Practicing Physics Previous Year MCQ for SSC CGL is one of the best ways to understand the exam pattern and improve accuracy. These questions are directly taken from past SSC CGL exams, covering key topics like Mechanics, Thermodynamics, Electricity, and Modern Physics. Solving them will help you analyze important trends, boost confidence, and enhance your problem-solving skills.
Answer the SSC CGL Physics Objective Questions
1. The damage of the human body due to radiation (X-rays or grays etc,) is measured in :
(1) Rem
(2) Roentgen
(3) Curie
(4) Rad
Answer is Option (1) for the Physics Previous Year MCQ
In the case of damage to human body due to radiation, the most important factor is the amount of the dose – the amount of energy actually deposited in the body. The absorbed radiation dose, the amount of energy absorbed per gram of body tissue, is usually measured in units called rads. Another unit of radation is the rem, or roentgen equivalent in man. For practical purposes, 1 rad (absorbed dose) = 1 rem or 1000 mrem (dose equivalent) (Source: United States Nuclear Regulatory Commission).
2. Transition ions absorb light in :
(1) infrared region
(2) ultraviolet region
(3) microwave region
(4) visible region
Answer is Option (4) for the Physics Previous Year MCQ
Transition metal ions have an incomplete set of 3d electrons. Changes in the energy of these electrons correspond to the energy of visible light. The absorption of visible light by these ions lend colour to gems.
3. Flywheel is an important part of a steam engine because it :
(1) accelerates the speed of the engine
(2) helps the engine in keeping the speed uniform
(3) decreases the moment of inertia
(4) gives strength to the engine
Answer is Option (2) for the Physics Previous Year MCQ
A flywheel is a rotating mechanical device that is used to store rotational energy. Flywheels have a significant moment of inertia and thus resist changes in rotational speed, enabling the engine to run at a constant, uniform motion. In the Industrial Revolution, James Watt contributed to the development of the flywheel in the steam engine.
4. The freezing point of fresh water is _______.
(1) 4°C
(2) 3°C
(3) 5°C
(4) 0°C
Answer is Option (4) for the Physics Previous Year MCQ
The freezing point of water is the temperature at which water changes phase from a liquid to a solid. Under normal conditions, ordinary water freezes at 0°C, or 32°F. The temperature may be lower if supercooling occurs or if there are impurities present in the water which could cause freezing point depression to occur.
5. The unit of noise pollution (level) is :
(1) decibel
(2) decimal
(3) ppm
(4) None of these
Answer is Option (1) for the Physics Previous Year MCQ
Noise pollution refers to any unpleasant, damaging or irritating noise that has the potential to harm people, wildlife or the environment. The decibel (dB) is the main unit used to measure the intensity or loudness of sounds. A sound can also be measured by its pitch, which is the frequency of sound vibrations per second.
6. Relative humidity is expressed as
(1) Grams
(2) Kilograms
(3) Percentage
(4) Ratio
Answer is Option (3) for the Physics Previous Year MCQ
Relative humidity is the amount of moisture in the air compared to what the air can “hold” at that temperature. It signifies the mass of water vapour present in the air expressed as a percentage of the mass. Relative humidity is the amount of moisture in the air compared to what the air can “hold” at that temperature. It signifies the mass of water vapour present in the air expressed as a percentage of the mass that would be present in an equal volume of saturated air at the same temperature. So Relative humidity is normally expressed as a percentage.
7. A real gas can act as an ideal gas in
(1) high pressure and low temperature
(2) low pressure and high temperature
(3) high pressure and high temperature
(4) low pressure and low temperature
Answer is Option (2) for the Physics Previous Year MCQ
Real gases approximate ideal gases when their pressure is relatively low, and their temperature reasonably high. A real gas deviates increasingly from ideality as it is compressed and cooled to near the point at which it will condense into a liquid. Compressing forces the molecules closer together so that intermolecular forces become stronger, and cooling reduces the kinetic energy of the molecules, so that they are more easily held by these forces.
8. According to special theory of relativity the mass of a particle
(1) increases with increase in velocity with respect to an observer.
(2) decreases with increase in velocity.
(3) decreases with decrease in velocity.
(4) is independent of its velocity.
Answer is Option (1) for the Physics Previous Year MCQ
According to the Special Theory of Relativity, the mass of a moving object measures more as its velocity increases until, at the speed of light, it becomes infinite. This is because as an object gains speed, it gains more (kinetic) energy.
9. The motion of the wheels of a bullock-cart while moving on the road is an example of
(1) Oscillatory and rotatory motion
(2) Oscillatory and translatory motion
(3) Translatory and rotatory motion
(4) Translatory motion only
Answer is Option (3) for the Physics Previous Year MCQ
There are four basic types of motion in mechanical systems: Rotary, Linear, Reciprocating and Oscillating motion. Rotatory motion is turning round in a circle, such as a wheel turning. While the wheel is moving, the mechanism transfers translational motion into rotary motion. As a matter of fact, translatory motion and rotatory motion occur at the same time.
10. Super conductors are substances that
(1) offer minimum resistance to flow of electric current
(2) conduct electricity at low temperature
(3) conduct electricity at high temperature
(4) offer high resistance to the flow of electric current
Answer is Option (1) for the Physics Previous Year MCQ
A superconductor is a material that can conduct electricity or transport electrons from one atom to another with no resistance. No heat, sound or any other form of energy is released from the material when it reaches the temperature at which it becomes superconductive.
11. A thin oil film on a water surface appears coloured because of
(1) reflection
(2) interference
(3) diffraction
(4) polarization
Answer is Option (2) for the Physics Previous Year MCQ
A thin oil film on a water surface appears coloured because of thin-film interference which involves the interference of light waves reflecting off the top surface of a film with the waves reflecting from the bottom surface. The refractive index of oil is larger than that of water, therefore the reflection on the back side occurs.
12. The ‘Greenhouse effect’ is mainly due to increase in atmospheric
(1) Ozone
(2) Nitrogen
(3) Sulphur dioxide
(4) Carbon dioxide
Answer is Option (4) for the Physics Previous Year MCQ
Carbon dioxide is the primary greenhouse gas that is contributing to recent climate change, 72% of the totally emitted greenhouse gases is carbon dioxide (CO2), 18% Methane and 9% Nitrous oxide (NO). Carbon dioxide emissions therefore are the most important cause of global warming.
13. In a conductor
(1) there is no conduction band
(2) the forbidden energy gap is very wide
(3) the forbidden energy gap is very narrow
(4) the valence band and the conduction band overlap each other
Answer is Option (4) for the Physics Previous Year MCQ
In the case of a conductor, there is no forbidden energy gap. The conduction and valence energy bands overlap each other. Obviously, the electrons from the valence band can freely enter the conduction energy band.
14. The moment of inertia of a body does not depend upon its
(1) axis of rotation
(2) angular velocity
(3) form of mass
(4) distribution of mass
Answer is Option (2) for the Physics Previous Year MCQ
Moment of inertia is the mass property of a rigid body that determines the torque needed for a desired angular acceleration about an axis of rotation. Moment of inertia depends on the shape of the body and the amount and distribution of its mass. It can be found through the sum of moments of inertia of the masses making up the whole object, under the same conditions.
15. To open a door easily, the handle should be fixed
(1) near the hinges
(2) away from mid-point opposite to hinges
(3) in the middle
(4) None of these
Answer is Option (4) for the Physics Previous Year MCQ
Since Torque = force x distance, to open a door easily, the handle should be fixed at the greatest distance from the hinges. If we pull with same force on a handle that is 2 feet away from the hinges, we will provide twice the torque, so it will be twice as easy to open.
16. Optical fibre works on the principle of
(1) refraction
(2) scattering
(3) interference
(4) total internal reflection
Answer is Option (4) for the Physics Previous Year MCQ
An Optical Fiber works on the principle of Total Internal Reflection. Light rays are reflected and guided down the length of an optical fiber. The acceptance angle of the fiber determines which light rays will be guided down the fiber.
17. The colours of stars depend on their
(1) temperature
(2) distance
(3) radius
(4) atmospheric pressure
Answer is Option (1) for the Physics Previous Year MCQ
The colour of a star tells about its temperature, and the temperature depends on some combination of the star’s mass and evolutionary phase.
18. The sky appears blue due to
(1) Rayleigh scattering
(2) Mie scattering
(3) Back scattering
(4) None of the above
Answer is Option (1) for the Physics Previous Year MCQ
The blue colour of the sky is due to Rayleigh scattering. As light moves through the atmosphere, most of the longer wavelengths pass straight through. Little of the red, orange and yellow light is affected by the air. However, much of the shorter wavelength light is absorbed by the gas molecules. The absorbed blue light is then radiated in different directions. It gets scattered all around the sky.
19. A particle is moving in a uniform circular motion with constant speed ‘v’ along a circle of radius ‘r’. The acceleration-of the particle is
(1) zero
(2) \(\displaystyle \frac{V}{r}\)
(3) \(\displaystyle \frac{V}{{{{r}^{2}}}}\)
(4) \(\displaystyle \frac{{{{V}^{2}}}}{r}\)
Answer is Option (4) for the Physics Previous Year MCQ
When a particle is moving in a uniform circular motion with constant speed and radius. the acceleration of the particle is given by \(\displaystyle \frac{{{{V}^{2}}}}{r}\). The particle will exhibit centripetal acceleration.
20. Which of the following devices can be used to detect radiant heat ?
(1) Liquid thermometer
(2) Six’s maximum and minimum thermometer
(3) Constant volume air thermometer
(4) Thermopile
Answer is Option (4) for the Physics Previous Year MCQ
Based on the thermoelectric effect, the thermopile can be used as a heat sensor to measure thermal radiation. A thermopile is made of thermocouple junction pairs connected electrically in series. Thermocouples near the ground measures radiant energy.
21. In which one of the following the phenomenon of total internal reflection of light is used ?
(1) Formation of mirage
(2) Working of binoculars
(3) Formation of rainbow
(4) Twinkling of stars
Answer is Option (3) for the Physics Previous Year MCQ
When the angle of incidence is greater than the critical angle, no refraction occurs. Instead, the incident beam is reflected, obeying the Law of Reflection. This is called Total internal reflection. In the formation of a rainbow, Total Internal Reflection occurs at the rear of the raindrop – the water-to-air interface.
22. Period of oscillation of 3 cm microwaves in seconds is
(1) 1 × \(\displaystyle {{10}^{{10}}}\)
(2) 1 × \(\displaystyle {{10}^{{-10}}}\)
(3) 0.01
(4) 0.001
Answer is Option (2) for the Physics Previous Year MCQ
The period of oscillation of 3 cm microwaves is 1 x \(\displaystyle {{10}^{{-10}}}\) (Physics, Volume 1, by Halliday). The period of oscillation is the smallest interval of time in which a system undergoing oscillation returns to the state it was in at the beginning of the oscillation.
23. The device used to convert solar energy into electricity is
(1) Photovoltaic cell
(2) Daniell cell
(3) Electrochemical cell
(4) Galvanic cell
Answer is Option (1) for the Physics Previous Year MCQ
Sunlight is converted into electricity using photovoltaics (PV). A photovoltaic system employs solar panels composed of a number of solar cells to supply usable solar power.
24. Light year is a unit of
(1) Light
(2) Current
(3) Distance
(4) Time
Answer is Option (3) for the Physics Previous Year MCQ
A light-year is a unit of length used informally to express astronomical distances. It is equal to just under 10 trillion kilometres.
25. It is easy to burst a gas-filled balloon with a needle than with a nail. It is because
(1) nail is more longer than needle.
(2) nail exerts more pressure than needle on the balloon.
(3) needle exerts more pressure than nail on the balloon.
(4) gas is reactive with the needle.
Answer is Option (3) for the Physics Previous Year MCQ
It is easy to burst a gas-filled balloon with a needle than with a nail because the needle applies more pressure than nail. Besides, the application of the pressure is on a small surface area than in the case of nail. In the case of needle, it is a very tiny area at the tip of the needle, so only a little force gives a lot of pressure (pressure = force/area).
26. Ice is packed in saw dust because
(1) saw dust will not get melted easily.
(2) saw dust is poor conductor of heat.
(3) saw dust is a good conductor of heat.
(4) saw dust does not stick to the ice.
Answer is Option (2) for the Physics Previous Year MCQ
Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since sawdust is a poor conductor of heat, it takes more time for the ice to absorb the required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.
27. The Dynamo converts
(1) Electrical Energy into Mechanical Energy
(2) Mechanical Energy into Magnetic Energy
(3) None of these
(4) Mechanical Energy into Electrical Energy
Answer is Option (4) for the Physics Previous Year MCQ
Dynamo is a device for converting mechanical energy into electrical energy, especially one that produces direct current. It uses electromagnetic principles to convert mechanical rotation into a pulsing direct electric current through the use of a commutator.
28. A Fuse wire is characterised by
(1) High resistance and low melting point
(2) High resistance and high melting point
(3) Low resistance and high melting point
(4) Low resistance and low melting point
Answer is Option (4) for the Physics Previous Year MCQ
A fuse is a type of low resistance resistor that acts as a sacrificial device to provide over current protection, of either the load or source circuit. Low resistance causes the fuse wire to melt if a current more than the safe current for the appliance starts flowing through the circuit. Besides, the wire of fuse has very low melting point. When high current flows through the circuit due to overloading or a short circuit, the wires get heated and melt. As a result, the circuit is broken and current stops flowing.
29. Burns caused by steam are much severe than those caused by boiling water because
(1) Steam pierces through the pores of body quickly
(2) Steam has latent heat
(3) Steam is gas and engulfs the body quickly
(4) Temperature of steam is higher
Answer is Option (2) for the Physics Previous Year MCQ
When water changes into steam, it absorbs latent heat, and when steam condenses to form water, it gives out an equal amount of latent heat. Bums caused by steam are much more severe than those caused by boiling water, simply because steam contains more heat (in the form of latent heat) than boiling water.
30. Which of the following options correctly explains the term heat budget?
(1) It is a mode of transfer of heat through matter by molecular activity.
(2) It is the balance between incoming and outgoing radiation
(3) It is the radiation from the earth in the form of long waves.
(4) It is the amount of heat which the surface of earth receives from the sun.
Answer is Option (2) for the Physics Previous Year MCQ
Incoming heat being absorbed by the Earth, and outgoing heat escaping the Earth in the form of radiation are both perfectly balanced. If they were not balanced, then Earth would be getting either progressively warmer or progressively cooler with each passing year. This balance between incoming and outgoing heat is known as Earth’s heat budget.
31. The purpose of choke in a fluorescent lamp is :
(1) to increase the current flow
(2) to decrease the current flow
(3) to decrease the resistance
(4) ro decrease the voltage momentarily
Answer is Option (2) for the Physics Previous Year MCQ
The choke primarily serves to limit current flow to the correct level for the tube. It also can be used during startup to provide an inductive ‘kick’ forming a momentary higher-voltage pulse to start the lamp.
32. The mercury and sodium street lamps light up because of :
(1) Atomic emission
(2) Atomic absorption
(3) Electron emission
(4) Electron absorption
Answer is Option (1) for the Physics Previous Year MCQ
The light in sodium vapour lamp and mercury vapour lamp is, because of electron emission. In case of Sodium Lamps, filaments of the lamp sputter fast moving electrons, which hit the sodium atoms (vapour) causing the valence electrons of the sodium atoms to excite to higher energy levels and the electrons thus excited relax by emitting the characteristic monochromatic bright yellow light. The mechanism in mercury vapour lamp is more involved and sequential. The sputtered electrons from the filaments, after having been accelerated by high voltage, hit the mercury atoms. Here also, the excited electrons of mercury atoms relax by emitting characteristic but ultraviolet light.
33. A person can jump higher on the moon’s surface than on the earth because :
(1) the moon’s surface is rough
(2) the acceleration due to gravity in moon is smaller than that on the earth.
(3) the moon is cooler than earth
(4) the moon has no atmosphere
Answer is Option (2) for the Physics Previous Year MCQ
The acceleration due to the gravitational field of moon (g = 1.62631 ms-2) is one-sixth of the acceleration due to gravity on the Earth. So the weight of the same body is also 1/6th on moon in comparison to that on the surface of the earth. It is due to this reason; a man can jump six times higher on moon than on earth.
34. Which one of the following is not a feature of Indifference Curve?
(1) They do not intersect each other
(2) They slope downwards to the right
(3) They are parallel to each other
(4) They are concave to each other
Answer is Option (4) for the Physics Previous Year MCQ
Indifference curves are usually convex to the origin. In other words, the indifference curve is relatively flatter in its right-hand portion and relatively steeper in its left-hand portion. The degree of convexity of an indifference curve depends on the rate of fall in the marginal rate of substitution.
35. The apparent weight of a man in a lift is less the real weight when :
(1) the lift is going up with an acceleration
(2) the lift is going down with uniform speed
(3) the lift is going up with uniform speed
(4) the lift is going down with an acceleration
Answer is Option (4) for the Physics Previous Year MCQ
If the lift accelerates downwards with acceleration a, then the apparent weight of the man standing in the lift will be less than the true weight of the man by an amount ma. On the contrary, if the lift accelerates upwards with acceleration, then the apparent weight of the man will be greater than his true weight.
36. Rainbows are produced when sunlight :
(1) Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction
(2) Incident on rain drops hanging in the atmosphere is dispersed after suffering refraction and internal reflection.
(3) Incident on raindrops hanging in the atmosphere is dispersed after suffering reflection.
(4) None of the given statements is correct
Answer is Option (2) for the Physics Previous Year MCQ
When the light rays from the Sun are incident on water drops hanging in the atmosphere; these rays are dispersed into seven colours of white light and internally reflected by the drops. This dispersion and internal reflection results in production of colour arcs which appear hanging in the sky and known as rainbow. So the solar rays incident on the rain drops are refracted, internally reflected and transmitted to form the rainbow.
37. Sound is heard over longer distances on rainy days because
(1) sound travels slowly in moist air
(2) sound travels faster in moist air
(3) moist air does not absorb sound
(4) moist air absorbs sound
Answer is Option (2) for the Physics Previous Year MCQ
The speed of sound in a medium is inversely proportional to the square root of its density. Higher is the humidity in the air, greater will be the velocity of sound. Therefore, the speed of sound in moist air is more than that in dry air. This is why the sirens of mills, whistle of trains and others are heard up to longer distances on a rainy day than on a dry day.
38. X–rays are
(1) positively charged particles
(2) negatively charged particles
(3) neutral particles
(4) None of these
Answer is Option (3) for the Physics Previous Year MCQ
Like gamma rays and neutrons, X-rays are electrically neutral. They have neither a positive nor a negative charge. They cannot be accelerated or made to change direction by a magnet or electrical field. In contrast, charged subatomic particles comprise light charged particles (electrons and positrons) and heavy charged particles (protons, alpha particles and heavier ions).
39. Railway tracks are banked on curves so that :
(1) the train may not fall down inwards.
(2) the weight of the train may be reduced.
(3) necessary centripetal force may be obtained from the horizontal component of the normal reaction due to track.
(4) no frictional force may be produced between the wheels and the track.
Answer is Option (3) for the Physics Previous Year MCQ
A vehicle moving at a fast speed on a straight rail/ road has a large inertia, i.e. tendency to keep moving in the same direction at the same speed. When it takes a circular turn on a curved rail/road, it experiences an additional force, termed as centripetal force, acting towards the centre of the circle. While rounding the curve as the vehicle has tendency to leave curved path and regain straight line path, force of friction between wheels and ground provides necessary centripetal force. In order that the vehicle can go round the curved track at a reasonable speed without skidding, the sufficient centripetal force is managed for it by banking the rail/road.
40. We feel cool when we sit near the fan, this is because
(1) fan gives cool air.
(2) fan cools surrounding air.
(3) air vapourises the sweat on our body.
(4) we feel cool when air touches the body.
Answer is Option (3) for the Physics Previous Year MCQ
We feel comfortable sitting under a fan when we are perspiring because a fan increases the rate of evaporation of sweat (or moisture) from our body and makes us feel cool and comfortable.
41. The average kinetic energy of the molecules of an ideal gas is directly proportional to
(1) Velocity of Molecules
(2) Mass of Molecules
(3) Absolute temperature of the gas
(4) Temperature of environment
Answer is Option (3) for the Physics Previous Year MCQ
The average kinetic energy of gas molecules is directly proportional to absolute temperature only. This implies that all molecular motion ceases if the temperature is reduced to absolute zero.
42. ‘Parsec’ is the unit measurement of
(1) Density of stars
(2) Astronomical distance
(3) Brightness of heavenly bodies
(4) Orbital velocity of giant stars
Answer is Option (2) for the Physics Previous Year MCQ
Parsec is a unit of distance used in astronomy to measure large distances to objects outside our Solar System. It is equal to about 3.26 light years (3.086 × \(\displaystyle {{10}^{{13}}}\) kilometres). One parsec is the distance at which one astronomical unit subtends an angle of one arcsecond.
43. The phenomenon of change in direction of light when it passes from one medium to another is called
(1) Propagation
(2) Reflection
(3) Refraction
(4) Dispersion
Answer is Option (3) for the Physics Previous Year MCQ
Refraction is the change in direction of wave propagation due to a change in its transmission medium. Due to the change of medium, the phase velocity of the wave is changed but its frequency remains constant. Refraction of light is the most commonly observed refractive phenomenon, but any type of wave can refract when it interacts with a medium.
44. Super cooling stands for cooling of a liquid :
(1) at freezing point
(2) below freezing point
(3) at melting point
(4) above melting point
Answer is Option (2) for the Physics Previous Year MCQ
Supercooling, also known as undercooling, is the process of lowering the temperature of a liquid or a gas below its freezing point without it becoming a solid. A good example of this phenomenon is clouds in high altitude that are an accumulation of supercooled droplets of water below their freezing point. Refrigeration is a popular commercial application of supercooling.
45. Alcohol is more volatile than water because _________ is lower than water.
(1) its boiling point
(2) its density
(3) its viscosity
(4) its surface tension
Answer is Option (1) for the Physics Previous Year MCQ
Drinking alcohol (ethanol) and a lot of other simple alcohols are more volatile than water because they are less polar. Thus, alcohol has higher vapor pressure and a lower boiling point than water; therefore, it evaporates more quickly. Its low boiling point of 78⁰ C is what makes it possible to distill alcohol into a much stronger solution than wine or beer.
46. Which term is not associated with sound wave?
(1) Hertz
(2) Decibel
(3) Candela
(4) Mach
Answer is Option (3) for the Physics Previous Year MCQ
Candela is the standard unit of luminous intensity, the luminous power per unit solid angle emitted by a point light source in a particular direction, in the International System of Units. The word candela means candle in Latin.
47. If an electron and a photon have the same wavelength, then they will have the same
(1) velocity
(2) linear momentum
(3) angular momentum
(4) energy
Answer is Option (2) for the Physics Previous Year MCQ
When a non-relativistic electron and a non-relativistic proton are moving and have the same de Broglie wavelength, then they will have the same linear momentum p = mv. If the electron and proton have the same momentum, they cannot have the same speed because of the difference in their masses. An electron and photon can have the same wavelength since the wavelength of electron can be changed by changing its velocity.
48. At boiling point of liquids, its
(1) Temperature increases
(2) Atmospheric pressure increases
(3) Temperature remains constant
(4) Vapour pressure decreases
Answer is Option (3) for the Physics Previous Year MCQ
An interesting property of matter is that its temperature remains constant during a phase change, assuming its surrounding pressure is constant. A liquid changes into gaseous state at a constant temperature called its boiling point. For example, when water is converted into vapors (gaseous state) at 100°C and so 100°C is its boiling point. The temperature remains constant at 100°C. The temperature of water increases only after all the water is evaporated. Likewise, once the temperature of a liquid is lowered to its freezing point, the temperature does not decrease until all the liquid has changed its phase to become a solid.
49. On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because
(1) Mercury is a metal
(2) Density of mercury is greater than that of water
(3) Cohesion of mercury is greater than its adhesion with glass
(4) Cohesion of water is greater than its adhesion with glass
Answer is Option (3) for the Physics Previous Year MCQ
When liquid is placed on a smooth surface like glass plate, the relative strengths of the cohesive and adhesive forces acting on that liquid determine the shape it will take (and whether or not it will wet the surface). If the adhesive forces between a liquid and a surface are stronger, they will pull the liquid down, causing it to wet the surface. However, if they cohesive forces among the liquid itself are stronger, they will resist such adhesion and cause the liquid to retain a spherical shape and bead the surface. Mercury drop remains spherical on a plate of glass because its cohesive force is greater than its adhesive force with glass.
50. Which of the following is an insulator?
(1) Mercury
(2) Carbon
(3) Germanium
(4) Glass
Answer is Option (4) for the Physics Previous Year MCQ
Insulators are materials that do not allow the transfer or that slow the transfer of heat or electricity. Some of the examples of insulators are: glass, plastic, rubber, porcelain, wood, ceramic, dry air, etc.
51. Name the process by which bubbles from liquid are formed?
(1) Effervescence
(2) Surface Tension
(3) Surface Energy
(4) Degasification
Answer is Option (1) for the Physics Previous Year MCQ
Effervescence is the escape of gas from an aqueous solution and the foaming or fizzing that results from a release of the gas. It leads to the formation of gas bubbles in a liquid. For example, when opening a bottle of champagne, beer or carbonated beverages such as soft drinks, the visible bubbles are produced by the escape from solution of the dissolved gas.
52. The boiling point of water depends upon the
(1) atmospheric pressure
(2) volume
(3) density
(4) mass
Answer is Option (1) for the Physics Previous Year MCQ
The boiling point corresponds of water to the temperature at which its vapour pressure equals the surrounding environmental pressure. So it is dependent on the atmospheric pressure. For example, at higher altitudes, the atmospheric pressure decreases. As this pressure decreases, the boiling point of the water also decreases.
53. What is the phenomenon which established the transverse nature of light ?
(1) Reflection
(2) Interference
(3) Diffraction
(4) Polarisation
Answer is Option (4) for the Physics Previous Year MCQ
The phenomena which prove the transverse nature of light is polarization. Since the intensity of polarized light on passing through a tourmaline crystal changes, with the relative orientation of its crystallographic axes with that of the polarizer, therefore light must consist of transverse waves. Transverse waves are waves that are oscillating perpendicularly to the direction of propagation.
54. What is the name of the device used to convert alternating current into direct current ?
(1) Ammeter
(2) Galvanometer
(3) Rectifier
(4) Transformer
Answer is Option (3) for the Physics Previous Year MCQ
A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
55. Why does ice covered in sawdust not melt quickly ?
(1) Sawdust does not allow the air to touch the ice
(2) The water is absorbed by sawdust
(3) Sawdust is a bad conductor of heat
(4) Sawdust is good conductor of heat
Answer is Option (3) for the Physics Previous Year MCQ
Ice needs to absorb heat energy to melt and become water (called latent heat of fusion). Since sawdust is a poor conductor of heat, it takes more time for the ice to absorb the required heat energy. This allows ice to remain in solid state for more time when packed in saw dust.
56. The washing machine works on the principle of
(1) Dialysis
(2) Diffusion
(3) Reverse osmosis
(4) Centrifugation
Answer is Option (4) for the Physics Previous Year MCQ
Washing machines work on the principle of centrifugation. They are based on medium sized centrifuges that put an object in rotation around a fixed axis, applying force perpendicular to the axis. It uses the sedimentation principle, where the centripetal acceleration separates substances of greater and lesser density. Besides, it also makes use of the centrifugal force generated in the “spin cycle” of washing machines that throws the water out through the little holes of perforated drum so that the washed clothes end up much drier.
57. The ‘Choke’ used with a tube light is basically
(1) an inductor
(2) a capacitor
(3) a transformer
(4) a resistor
Answer is Option (1) for the Physics Previous Year MCQ
In electronics, a choke is an inductor used to block higher-frequency alternating current (AC) in an electrical circuit, while passing lower-frequency or direct current (DC). In a tubelight, the high voltage is created by suddenly interrupting the current in choke, which is connected in series with the tubelight.
58. Curie is an unit of
(1) Radioactivity
(2) energy of Gamma rays
(3) intensity of Gamma rays
(4) work function
Answer is Option (1) for the Physics Previous Year MCQ
The curie (symbol Ci) is a non-SI unit of radioactivity, named ‘in honour of’ Pierre Curie. It was originally defined as “the quantity or mass of radium emanation in equilibrium with one gram of radium (element)”, but is currently defined as: 1 Ci = 3.7 × \(\displaystyle {{10}^{{10}}}\) decays per second after more accurate measurements of the activity of 226Ra.
59. Energy travels from Sun to Earth through
(1) conduction
(2) convection
(3) radiation
(4) modulation
Answer is Option (3) for the Physics Previous Year MCQ
Solar energy, in the form of heat and light, travels from the sun to Earth through the process of radiation. This way, energy can be transferred through empty space without relying on matter. This radiation is largely visible as light to the naked eye, although it also includes ultraviolet and infrared radiation as well.
60. Heat is transmitted from higher temperature to lower temperature through the actual motion of the molecules in
(1) Conduction
(2) Convection
(3) Radiation
(4) Both conduction and convection
Answer is Option (2) for the Physics Previous Year MCQ
The process of heat transfer from one place to another place without the movement of particles is called conduction Example: Heat transfer through Metal rods. On the contrary, convection is the process by which heat is transmitted through a substance from a point to another due to the bodily motion of the heated particles of the substance. The fluids (liquids and gases) are heated by this process.
61. Which one among the following components is used as an amplifying device?
(1) Transformer
(2) Diode
(3) Capacitor
(4) Transistor
Answer is Option (4) for the Physics Previous Year MCQ
An amplifier is an electronic device that increases the voltage, current, or power of a signal. Generally, transistors are active devices that can be used with discrete components to amplify voltage, power or both depending upon the configuration.
62. The unit of measurement of noise is
(1) Decibel
(2) Hertz
(3) Amplifier
(4) Acoustics
Answer is Option (1) for the Physics Previous Year MCQ
The decibel (dB) is the unit used to measure the intensity of sound or noise level. It is given in terms of a logarithmic function of a ratio of power intensities. One decibel is one tenth of one bel, named in honor of Alexander Graham Bell who was the inventor of the telephone and phonograph.
63. The commonly used coolant in refrigerators is
(1) Ammonia
(2) Nitrogen
(3) Freon
(4) Oxygen
Answer is Option (3) for the Physics Previous Year MCQ
Modern refrigerators usually use a refrigerant called HFC-134a (1,1,1,2-Tetrafluoroethane), which does not deplete the ozone layer, instead of Freon. Freon used to be the most common refrigerant till the 1980s; however, its use has declined since the 1990s because it comes under Chlorofluorocarbon (CFC). Ammonia was also used a a common refrigerant in old refrigerators. However, Freon still remains the most commonly used refrigerant. Hydrochlorofluorocarbon (HCFC), is a type of refrigerator coolant used in newer refrigerator models. The types used today include HFC-134a, HCFC-142b and HCFC-22.
64. A galvanometer can be converted into a voltmeter by connecting with it a
(1) high resistance in parallel
(2) low resistance on parallel
(3) high resistance on series
(4) low resistance in series
Answer is Option (3) for the Physics Previous Year MCQ
In order to convert a Galvanometer into voltmeter, a very high resistance known as “series resistance” is connected in series with the galvanometer. The conversion is made for enabling the galvanometer to measure the potential difference across any component in a circuit.
65. During which of the following operating conditions of an automobile, carbon monoxide content in exhaust gas is maximum?
(1) Acceleration
(2) Cruising
(3) Idle running
(4) Deacceleration
Answer is Option (3) for the Physics Previous Year MCQ
High Carbon Monoxide (CO) content in exhaust gas of automobiles usually indicate a fuel mixture richer than ideal (rich mixture – air fuel ratio below 14.7). High CO levels result from inadequate Oxygen supply needed for complete combustion that is caused by a too rich mixture – too much fuel or not enough air. This is most seen during :
(1) Idle running or low idle speed;
(2) Improper float settings in carbureted vehicles;
(3) Dirty or restricted air filters;
(4) Excessively dirty or contaminated oil
66. The least distance of distinct vision is
(1) 35 cm
(2) 25 cm
(3) 45 cm
(4) 15 cm
Answer is Option (2) for the Physics Previous Year MCQ
Least distance of distinct vision is the minimum object’s distance that is able to produce a distinct image on the retina. This distance is about 25 cm from the eye. However, it varies with age. For infants the least distance of distinct vision is about 5 to 8 cm.
67. The component used for tuning a radio is basically a variable
(1) Resistor
(2) Condenser
(3) Inductor
(4) Transformer
Answer is Option (2) for the Physics Previous Year MCQ
A tuning capacitor or tuning condenser is a variable capacitor used in an electronic circuit of a radio. It usually connects in parallel to a loop antenna and its capacitance may be intentionally and repeatedly changed mechanically or electronically.
68. 0°K is equivalent to
(1) 273°C
(2) – 273°C
(3) 0°C
(4) 100°C
Answer is Option (2) for the Physics Previous Year MCQ
0 degrees Kelvin is equal to -273.15 degrees Celsius. It is the lowest possible temperature, at which all molecules have the least possible amount of kinetic energy. It refers to a state at which the enthalpy and entropy of a cooled ideal gas reaches its minimum value, taken as 0.
69. In an optical fibre the signal is transmitted
(1) in a straight line path
(2) In a curved path
(3) due to total internal reflection
(4) Due to refraction
Answer is Option (3) for the Physics Previous Year MCQ
Total internal reflection is the basic concept behind the optical fiber. Optical fiber employs the transmission of light down fibers of plastic or glass. Because the fibers are thin, light entering one is likely to strike the inside surface at an angle greater than the critical angle and, thus, be totally reflected. In fact, most fibers have a varying refractive index to allow more light to be guided along the fiber through total internal refraction.
70. What type of lens is used to correct vision of a person suffering from Myopia?
(1) Convex lens
(2) Concave lens
(3) Crossed lens
(4) Cylindrical lens
Answer is Option (2) for the Physics Previous Year MCQ
Near-sightedness, also known as short-sightedness and myopia, is a condition of the eye where light focuses in front of, instead of on, the retina. This causes distant objects to be blurry while close objects appear normal. This defect can be corrected by wearing a concave (diverging) spectacle lens. The rays of light from a near object are diverged before entering the eye so that the cornea and eye lens can direct the focal point onto the retina.
71. A man standing close to the platform at a railway station experiences a pulling force towards a fast moving train because of __________ .
(1) gravitational force between train and man
(2) illusion of the man
(3) the centripetal force
(4) pressure difference due to fast moving air in between
Answer is Option (4) for the Physics Previous Year MCQ
When a fast-moving train passes a man standing on the platform at rest, the air between train and person also moves with greater speed. This rapidly moving air, by Bernoulli’s principle will have a lower pressure than the still air a few feet away. The still air, having higher pressure, and being behind the man standing close will tend to push him toward the train.
72. Water is used in a hot water bag because
(1) It is easily available
(2) It has high specific gravity
(3) It has high specific heat
(4) It is a liquid substance
Answer is Option (3) for the Physics Previous Year MCQ
Water has the highest specific heat of any known substance except hydrogen; that is, it requires more heat to raise the temperature of water a definite number of degrees than it does to raise the temperature of an equal amount of any other substance the same number of degrees. Practically this same thing can be stated in another way: Water in cooling gives out more heat than any other substance in cooling through the same number of degrees. For this reason water is used in foot warmers and in hot-water bags (General Science by Bertha Clark).
73. The temperature of a liquid is 32°F. What is its temperature in Celsius scale?
(1) 32° C
(2) 0° C
(3) 100° C
(4) 212° C
Answer is Option (2) for the Physics Previous Year MCQ
The formulas for converting between degree Celsius and degree Fahrenheit are: °F = °C 9/5 + 32 and °C = (°F – 32) 5/9. So, in Celsius scale, 32° F= 0° C
74. The point where total mass of a body is supposed to be concentrated is known as
(1) Dead centre
(2) Centre of mass
(3) Centre of gravity
(4) Centre of motion
Answer is Option (2) for the Physics Previous Year MCQ
The centre of mass of a body or a system of particles is defined as a single point at which the whole mass of the body or system is imagined to be concentrated and all the applied forces acts at that point. It is that point that moves when forces are applied on the body.
75. Where do the electrical charges reside in a charged conductor?
(1) at the core
(2) throughout the body
(3) depended upon the nature of the body
(4) outer surface of the body
Answer is Option (4) for the Physics Previous Year MCQ
In all conductors, charges reside on the surface. The reason for this is that conductors have free electrons, that is, the electrons are loosely attached to the nucleus of the atoms in the conductors. When a solid conductor in equilibrium carries a net charge, the charge resides on the outer surface of the conductor. Besides, the electric field just outside the conductor is perpendicular to the surface and that the field inside is zero.
76. The colour of the ocean appears to be blue because the sunlight falling on it is
(1) reflected
(2) refracted
(3) diffracted
(4) scattered
Answer is Option (4) for the Physics Previous Year MCQ
The reason the ocean is blue is due to the absorption and scattering of light. The blue wavelengths of light are scattered, similar to the scattering of blue light in the sky but absorption is a much larger factor than scattering for the clear ocean water. In water, absorption is strong in the red and weak in the blue, thus red light is absorbed quickly in the ocean leaving blue. The red, yellow, and green wavelengths of sunlight are absorbed by water molecules in the ocean.
77. Which of the following is not true about X-rays?
(1) have low penetrating power
(2) travel with the speed of light
(3) Can be reflected or refracted
(4) can affect photographic plates
Answer is Option (1) for the Physics Previous Year MCQ
X-rays and gamma rays are photons, i.e. high energy light-waves. When emitted by a source, for example, radium or cobalt, located outside the body, they easily pass through the body, hence they are usually called penetrating radiation. Because X-rays are penetrating, they can be used in diagnostic medicine to image human bones or human organs made opaque by a dye.
78. What type of force acts on a car moving around a curve?
(1) Centrifugal force
(2) Cohesive force
(3) Centripetal force
(4) Gravitational force
Answer is Option (3) for the Physics Previous Year MCQ
Any object moving in a circle (or along a circular path) experiences a centripetal force. It is this physical force that pushes or pulls the object towards the center of the circle. In the case of a car moving along a curve, as it makes a turn, the force of friction acting upon the turned wheels of the car provides centripetal force required for circular motion. The net force on a car travelling around a curve is the centripetal force, \(\displaystyle {{F}_{C}}=m{{v}^{2}}/r\), directed toward the center of the curve.
79. Which phenomenon is responsible for the echo of sound wave?
(1) Reflection
(2) Refraction
(3) Interference
(4) Polarisation
Answer is Option (1) for the Physics Previous Year MCQ
Reflection of sound waves off of surfaces lead to one of two phenomena – an echo or a reverberation. The echo is produced due to hitting of the sound waves with the obstacles which makes the sound to reflect back. Echoes occur when a reflected sound wave reaches the ear more than 0.1 seconds after the original sound wave was heard.
80. Which of the metals has the maximum thermal conductivity?
(1) Iron
(2) Aluminium
(3) Silver
(4) Copper
Answer is Option (3) for the Physics Previous Year MCQ
Silver has the best thermal conductivity of 429 W/mK at RT (295K). It is followed by copper, gold and aluminium. Metals generally have very good electrical conductivity, that leads to high thermal conductivity. There is a rule governing the relation between electrical conductivity and thermal conductivity, called Wiedemann-Franz Law.
81. Which of the following is the cleanest source of energy?
(1) Biofuel
(2) Fossil fuel
(3) Nuclear power
(4) Wind energy
Answer is Option (4) for the Physics Previous Year MCQ
Solar, wind and hydro power are examples of cleanest energy sources. According to a new US study, Greenhouse gases produced over the lifetime of a wind turbine are less than that of fossil-fuel based energy sources and most other renewable. Only ocean energy (wave and tidal) and hydropower have lower emissions than wind. As a clean, fuel-free source of energy, wind turbines create energy without generating the damaging pollutants.
82. Which one of the following is an ohmic conductor?
(1) Germanium
(2) Silicon
(3) Carbon
(4) Silver
Answer is Option (4) for the Physics Previous Year MCQ
Ohmic conductors are conductors that obey Ohm’s law, that is Voltage/Current ratio is constant; in other words, the equation Resistance = Voltage/Current is obeyed. An Ohmic conductor’s resistance does not change with varying current. Metallic conductors such as silver are Ohmic conductors.
83. The spring balance works on the principle of __________ .
(1) Boyle’s Law
(2) Hooke’s Law
(3) Bernoulli’s principle
(4) Pascal’s Law
Answer is Option (2) for the Physics Previous Year MCQ
A spring scale or spring balance or Newton meter is a type of weighing scale. It consists of spring fixed at one end with a hook to attach an object at the other. It works by Hooke’s Law, which states that the force needed to extend a spring is proportional to the distance that spring is extended from its rest position.
84. If there were no gravity, which of the following will not be there for a fluid?
(1) Viscosity
(2) Surface Tension
(3) Pressure
(4) Upward Thrust
Answer is Option (4) for the Physics Previous Year MCQ
If there is no gravity, there will not be any upward thrust to keep a liquid buoyant. Whenever a body is placed in a fluid, the fluid applies resultant up ward directional force on the body and it is called up thrust. It’s numerical value which is the product of volume of the fluid displaced, density of the fluid and acceleration due to gravity at the given place. Up thrust increases with increase in acceleration due to gravity and vice versa.
85. Sun appears red in colour at sunrise and sunset due to
(1) the fact that sun emits only red colour at that time
(2) red light having longer wave length scatters away
(3) that sun comes out of the mountains
(4) that all other colours scatter away except red
Answer is Option (4) for the Physics Previous Year MCQ
According to Rayleigh’s law, the intensity of scattered light varies inversely as the fourth power of its wavelength. Sunlight consists of seven colours. Of these, red has the maximum wavelength. During sunrise and sunset, the rays have to travel a larger part of the atmosphere because they are very close to the horizon. Therefore, light other than red is mostly scattered away. Most of the red light, which is the least scattered, enters our eyes. Hence, the sun and the sky appear red.
86. At hill stations, the boiling point of water will be
(1) same as at sea level
(2) less than that at sea level
(3) more than that at sea level
(4) equal to the melting point of ice
Answer is Option (2) for the Physics Previous Year MCQ
The boiling point is the temperature at which the vapour pressure of the liquid equals the environmental pressure surrounding the liquid. Atmospheric pressure is due to air above any given point. The atmospheric pressure at high altitudes like hill station is less than at the sea level. Thus, vapour pressure will equal atmospheric pressure at a comparatively low temperature. Thus, the boiling point of water is reduced less than at sea level.
87. When we see an object, the image formed on the retina is
(1) Real and inverted
(2) Real and erect
(3) Virtual and erect
(4) Virtual and inverted
Answer is Option (1) for the Physics Previous Year MCQ
The retina is the thin light-sensitive membrane lining the inner eyeball-towards the back of the eye. As our eye lens are convex in nature, they form mostly real and inverted images on the retina. When the images formed are real and inverted, the message sent by the optic nerve are chemical impulses which turn them into erect images that we see.
88. Kinetic energy depends on
(1) the velocity or speed of the moving body.
(2) the mass of the moving body
(3) the pressure of the moving body
(4) both mass and velocity of the moving body
Answer is Option (4) for the Physics Previous Year MCQ
Kinetic energy is the energy associated with the movement of objects. The amount of kinetic energy that an object has depends upon two variables: the mass (m) of the object and the speed (v) of the object. The following equation is used to represent the kinetic energy (KE) of an object:
KE = \(\displaystyle \frac{1}{2}m{{v}^{2}}\)
89. In which form is the supplied heat energy stored during change in temperature of substance?
(1) Heat energy
(2) Kinetic energy
(3) Potential energy
(4) Both kinetic and potential energy
Answer is Option (2) for the Physics Previous Year MCQ
Temperature is used as a measure for heat in an object by measuring the amount of kinetic energy in the molecules that make up the object. It is a measure of the average kinetic energy of the random molecular motion. Heat is a form of energy that can be transferred from the heat source to the molecules, and it can also change its form from heat to movement. The molecules that gain extra energy will have a higher tendency to move more than the molecules that have not gained the extra energy. Energy of motion is called kinetic energy. When the molecules move or vibrate more, they have a higher kinetic energy, and this is recorded as an increase in temperature. In nutshell, as a body gains or loses kinetic energy its temperature will increase or decrease.
90. A galvanometer can be converted to a voltmeter by connecting
(1) a high resistance in parallel
(2) a high resistance in series
(3) a low resistance in series
(4) a low resistance in parallel
Answer is Option (2) for the Physics Previous Year MCQ
In order to convert a Galvanometer into voltmeter, a very high resistance known as “series resistance” is connected in series with the galvanometer. The conversion is made for enabling the galvanometer to measure the potential difference across any component in a circuit.
91. The frequency of direct current is _______
(1) Zero
(2) 50 HZ
(3) 60 HZ
(4) 100 HZ
Answer is Option (1) for the Physics Previous Year MCQ
Direct Current (DC) refers to power systems that use only one polarity of voltage or current, and to refer to the constant, zero-frequency, or slowly varying local mean value of a voltage or current. It is unidirectional flow of electric charge. Direct current is produced by sources such as batteries, power supplies, thermocouples, solar cells, or dynamos.
92. For photoelectric effect to take place, the metal used as the cathode should have______
(1) high melting point
(2) low melting point
(3) low work function
(4) low resistance
Answer is Option (3) for the Physics Previous Year MCQ
The photoelectric effect is the propensity of high energy electromagnetic radiation to eject electrons from a given material. The photoelectric effect has been utilized in devices called photocells, consisting of two electrodes in a sealed vacuum tube. By coating one electrode (the photocathode) with a alkali metal of low work function, a photo current could be generated even from visible light. Work function is the minimum energy needed to remove an electron from the surface of a material.
93. Flemings “Left hand Rule” is associated with the effect of
(1) Electric field on current
(2) Magnetic field on magnet
(3) Electric field on magnet
(4) Magnetic Field on current
Answer is Option (4) for the Physics Previous Year MCQ
Whenever, a current carrying conductor comes under a magnetic field, there will be force acting on the conductor and on the other hand, if a conductor is forcefully brought under a magnetic field, there will be an induced current in that conductor. In both of the phenomenon, there is a relation between magnetic field, current and force. This relation is directionally determined by Fleming Left Hand rule and Fleming Right Hand rule respectively.
94. Every hot object emits _____
(1) X–rays
(2) Visible light
(3) Infrared rays
(4) Ultraviolet rays
Answer is Option (3) for the Physics Previous Year MCQ
As per Planck’s law, all objects emit electromagnetic radiation according to their temperature. Colder objects emit waves with very low frequency (such as radio or microwaves), while hot objects emit infrared rays or even ultraviolet and higher frequencies. At room temperature, most of the radiation is in the infra-red region.
95. In hydel power station, the motion produced in turbines is due to
(1) flow of water
(2) burning of coal
(3) burning of diesel
(4) production of steam
Answer is Option (1) for the Physics Previous Year MCQ
A water turbine is a rotary machine that converts kinetic energy and potential energy of water into mechanical work. Hydroelectric power comes from water at work, water in motion. To generate electricity, water must be in motion. This is kinetic (moving) energy. When flowing water turns blades in a turbine, the form is changed to mechanical (machine) energy. The turbine turns the generator rotor which then converts this mechanical energy into another energy form — electricity.
96. Two vectors are said to be equal if
(1) only their magnitudes are same
(2) only their directions are same
(3) both magnitude and direction are same
(4) magnitudes are same but directions are opposite
Answer is Option (3) for the Physics Previous Year MCQ
If the magnitude as well as direction of two vectors are equal, then they are known as equal vectors. In other words, two vectors are said to be equal, if they possess equal magnitude and are headed towards the same direction. For two equal vectors, their directed line segments must be parallel.
97. Fuse wire is made of an alloy of
(1) Tin and Lead
(2) Tin and Copper
(3) Lead and Copper
(4) Copper and Silver
Answer is Option (1) for the Physics Previous Year MCQ
The common material used as fuse wire is an alloy of tin and lead (63% tin and 37% lead). Fuse wires provide overcurrent protection of an electrical circuit including the source of power and the load. Its essential component is a metal wire or strip that melts when too much current flows through it, thereby interrupting the flow of current.
98. Which of the following has the lowest frequency?
(1) Visible light
(2) Gamma rays
(3) Xrays
(4) Ultra violet rays
Answer is Option (1) for the Physics Previous Year MCQ
The electromagnetic spectrum is generally divided into seven regions, in order of decreasing wavelength and increasing energy and frequency: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays and gamma rays. So, among the given options, visible lights has the lowest frequency, while gamma rays have the highest.
99. A fresh egg when placed in salt water will
(1) sink and go to the bottom
(2) sink but will not go to the bottom
(3) float
(4) burst
Answer is Option (3) for the Physics Previous Year MCQ
When a fresh egg is placed in regular water, it sinks. However, when the same egg is placed in saltwater, it floats. This is because salt water is denser than the egg causing it to float.
100. Sending a frame to a group of stations is known as
(1) Single casting
(2) Spreading
(3) Multicasting
(4) Casting
Answer is Option (3) for the Physics Previous Year MCQ
In addition to transmitting frames directed to a single address, local area networks are capable of sending frames directed to a group of address, called a multicast address, which can be received by a group of stations. They can also send frames directed to all stations using the broadcast address. A frame sent to multicast destination address can be received by all stations configured to listen for that multicast address.
101. Which one among the following components cannot be developed within an “integrated circuit”?
(1) Diode
(2) Triode
(3) Transformer
(4) Transistor
Answer is Option (3) for the Physics Previous Year MCQ
Some components like transformers and inductors cannot be integrated into an IC except for very specialized high frequency applications. They have to be connected externally to the semiconductor pins. In general, transformers are located in circuit boards as separate components and cannot be integrated into semiconductor based integrated circuits.
102. A particle is thrown vertically upward. When it reaches the highest point, it has
(1) a downward acceleration
(2) an upward acceleration
(3) a downward velocity
(4) a horizontal velocity
Answer is Option (1) for the Physics Previous Year MCQ
When a particle is thrown vertically upwards in space, it will experience constant acceleration towards the ground (irrespective of the direction in which it is moving in), known as acceleration due to gravity. At the highest point, it has zero velocity but has downward acceleration equal to acceleration due to gravity.
103. The quality or tone of a musical sound produced by a stringed instrument depends on
(1) frequency of vibration
(2) length of the strings in the instrument
(3) Amplitude of vibration
(4) wave form of the sound
Answer is Option (4) for the Physics Previous Year MCQ
The timbre or quality of a sound depends on its wave form, which varies with the number of overtones, or harmonics, that are present, their frequencies, and their relative intensities. In simple terms, timbre is what makes a particular musical sound have a different sound from another, even when they have the same pitch and loudness.
104. Why does a cannon recoil after firing ?
(1) Conservation of energy
(2) Backward thrust of gases produced
(3) Newton’s third law of motion
(4) Newton’s first law of motion
Answer is Option (3) for the Physics Previous Year MCQ
Recoil is the backward momentum of a gun when it is discharged. In technical terms, the recoil caused by the gun exactly balances the forward momentum of the projectile and exhaust gases (ejecta), According to Newton’s third law. In case of canons, the momentum is transferred to the ground through its mount.
105. A bomb explodes on the moon. You will hear its sound on earth after ______
(1) 20 minutes
(2) 2 hours 20 minutes
(3) 3.7 hours
(4) You cannot hear the sound of explosion
Answer is Option (4) for the Physics Previous Year MCQ
The sound will never reach Earth because there are not enough molecules or atoms of matter per cubic centimeter of space to create the pressure waves in a medium that is a sound wave. In simple words, Sound propagation needs a medium. The people on the Earth can see the flash, but no sound.
106. Person who is colour blind cannot distinguish between
(1) Black and yellow
(2) Red and green
(3) Yellow and white
(4) Green and blue
Answer is Option (2) for the Physics Previous Year MCQ
Color blindness is the decreased ability to see color or differences in color. The most common form of colour blindness is known as red/green colour blindness and most colour blind people suffer from this. Those affected have difficulty with discriminating red and green hues due to the absence or mutation of the red or green retinal photoreceptors.
107. During the motion of a projectile fired from the earth surface, _______
(1) its kinetic energy remains constant
(2) its momentum remains constant
(3) vertical component of its velocity remains constant
(4) horizontal component of its velocity remains constant
Answer is Option (4) for the Physics Previous Year MCQ
The motion of a projectile is a two-dimensional motion—Horizontal motion and vertical motion—that take place independent of each other. The horizontal velocity of a projectile is constant (a never changing in value). The force of gravity continuously affects the vertical component, so the vertical motion is a uniformly accelerated motion.
108. Which of the following waves cannot be polarised?
(1) Radio
(2) Ultra violet
(3) Infrared
(4) Ultrasonic
Answer is Option (4) for the Physics Previous Year MCQ
Only transverse waves (such as radio, ultraviolet and infrared waves) can be polarized since their vibrations can potentially occur in all directions perpendicular to the direction of travel. It is therefore possible to confine the vibrations to a single plane. However, sound waves are longitudinal in which vibrations are parallel to the direction of travel of the wave. The vibrations of a longitudinal wave occur along a single line, it is therefore not possible to confine that to a plane. So it cannot be polarized.
109. Absolute Zero is defined as
(1) The temperature at which all molecular motion ceases
(2) At which water boils at 298K
(3) At which liquid Helium boils
(4) At which the volume becomes zero
Answer is Option (1) for the Physics Previous Year MCQ
Absolute zero is the temperature at which all motion in matter stops and is thought to be unreachable. It is the point at which the fundamental particles of nature have minimal vibrational motion, retaining only quantum mechanical, zero-point energy induced particle motion. By international agreement, absolute zero is defined as precisely; 0 K on the Kelvin scale, which is a thermodynamic (absolute) temperature scale; and –273.15 degrees Celsius on the Celsius scale.
110. Electromagnet is constructed with which of the following ?
(1) Steel
(2) Soft Iron
(3) Aluminum
(4) Nickel
Answer is Option (2) for the Physics Previous Year MCQ
An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. The magnetic field disappears when the current is turned off. It is made of soft iron since it has the property of losing its magnetism very quickly. The soft iron core of the electromagnet makes the magnetic field stronger.
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