Answer is Option (4) for SSC Section Officer Physics MCQ

The most common function of a diode is to allow an electric current to pass in one direction (called the diode’s forward direction), while blocking current in the opposite direction (the reverse direction).This unidirectional behavior is called rectification or verification and is used to convert alternating current to direct current, including extraction of modulation from radio signals in radio receivers— these diodes are forms of rectifiers diode is a two terminal electronic component with an asymmetric transfer characteristic, with low (ideally zero) resistance to current flow in one direction, and high (ideally infinite) resistance in the other.

Answer is Option (1) for SSC Section Officer Physics MCQ

Homi Jehangir Bhabha was an Indian nuclear physicist, founding director, and professor of physics at the Tata Institute of Fundamental Research. Colloquially known as “father of Indian nuclear programme,” Bhabha gained international prominence after deriving a correct expression for the probability of scattering positrons by electrons, a process now known as Bhabha scattering. His major contribution included his work on Compton scattering, R-process, and furthermore the advancement of nuclear physics. He was awarded Padma Bhushan by Government of India in 1954.

Answer is Option (3) for SSC Section Officer Physics MCQ

The heat content of anthracite ranges from 22 to 28 million Btu per short ton (26 to 33 MJ/kg) on a moist, mineral-matter-free basis. Anthracite (“coallike”) is a hard, compact variety of mineral coal that has a high luster. It has the highest carbon content, the fewest impurities, and the highest calorific content of all types of coals, which also include bituminous coal and lignite. Anthracite is the most metamorphosed type of coal (but still represents low-grade metamorphism), in which the carbon content is between 92.1% and 98%.

Answer is Option (1) for SSC Section Officer Physics MCQ

Frequency modulation (FM) conveys information over a carrier wave by varying its instantaneous frequency. This contrasts with amplitude modulation, in which the amplitude of the carrier is varied while its frequency remains constant. Frequency modulation is also used in telemetry, radar, seismic prospecting and newborn EEG seizure monitoring. Frequency modulation is known as phase modulation when the carrier phase modulation is the time integral of the FM signal. FM is widely used for broadcasting music and speech, two-way radio systems, magnetic taperecording systems and some video-transmission systems.

Answer is Option (1) for SSC Section Officer Physics MCQ

Brake force, also known as Brake Power, is a measure of braking power of a vehicle. Suppose a car whose mass is ‘x’ and is braked from a speed of y km/hr to come to halt at a uniform retardation in z min. If the speed of the car is doubled in the same distance, then the braking force required to stop the car is four times the original speed i.e. ‘4v’. Note that all the parameters remain to be same.

Answer is Option (2) for SSC Section Officer Physics MCQ

The quantity of impulse is force × time interval. In classical mechanics, linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter or moving slower, then it would have less momentum.

Answer is Option (2) for SSC Section Officer Physics MCQ

The fundamental qualities of Physics are the seven basic quantities that can be used to express all other physical quantities. These are as follows:

Length: Metre,

Heat: Kelvin,

Time: second,

Luminous Intensity: Candela,

Mass: Kilogram,

Electric Current: Ampere,

Amount of substance: Moles.

Answer is Option (1) for SSC Section Officer Physics MCQ

The hole size will increase because in expansion the size between two molecules do not increase so when the molecules on the outer edge move outward. Due to expansion, the size of the hole will also increase so as to compensate the distance change between the molecules. Thermal expansion is the tendency of matter to change in volume in response to a change in temperature. When a substance is heated, its particles begin moving more and thus usually maintain a greater average separation.

Answer is Option (2) for SSC Section Officer Physics MCQ

Radius of a capillary tube is inversely proportional to the height of the liquid column. So, if radius of the tube is doubled, rise of level of water will becomes half of the previous rise in capillary tube. Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper, in some non-porous materials such as liquefied carbon fiber, or in a cell. It occurs because of inter-molecular attractive forces between the liquid and solid surrounding surfaces.

Answer is Option (3) for SSC Section Officer Physics MCQ

According to Archimedes principle and we can note that the amount of water displaced by a needle is lesser than the amount of water moved out by the needle (that is displacement of the needle). So the needle initially stays on the surface of the water and then sinks into the water. Surface tension is a contractive tendency of the surface of a liquid that allows it to resist an external force. It is revealed, for example, in the floating of some objects on the surface of water, even though they are denser than water, and in the ability of some insects (e.g. water striders) to run on the water surface. This property is caused by cohesion of similar molecules, and is responsible for many of the behaviors of liquids.

Answer is Option (1) for SSC Section Officer Physics MCQ

The mass of a star which is two times the mass of the sun turns into a neutron star. A neutron star is a type of stellar remnant that can result from the gravitational collapse of a massive star during a Type II, Type Ib or Type Ic supernova event. Such stars are composed almost entirely of neutrons, which are subatomic particles without electrical charge and with slightly larger mass than protons. Neutron stars are very hot and are supported against further collapse by quantum degeneracy pressure due to the Pauli’s exclusion principle. This principle states that no two neutrons (or any other fermionic particles) can occupy the same place and quantum state simultaneously. A typical neutron star has a mass between about 1.4 and 3.2 solar masses (Chandrasekhar Limit), with a corresponding radius of about 12 km if the Akmal– Pandharipande–Ravenhall equation of state (APR EOS) is used.

Answer is Option (1) for SSC Section Officer Physics MCQ

Any mass is attracted to the Earth by the pull of gravity. Gravity accelerates all objects towards the ground at a specific rate. Without any other forces present, the speed of an object in free fall will increase the farther or longer it falls. In general the air resistance on an object depends upon several variables. First, it depends upon the shape of the object. Its shape determines the object’s drag coefficient: the more aerodynamic the shape, the less drag. Second, it depends upon the size of the object; specifically the cross-sectional area presented to the airflow (perpendicular to the direction of travel). And lastly, it depends upon the speed of the object. At low speeds the object’s resistance is directly proportional to speed, and at higher speeds the object’s resistance is proportional to its speed squared. Most objects falling through the air would be considered to be moving at a higher speed, even though that speed might not be great compared to some velocities.

Answer is Option (3) for SSC Section Officer Physics MCQ

All Electrostatic Copiers work under the premise that a charge of electricity is placed on an Image Drum which has the ability to retain the electric charge much like a capacitor holds its charge but with the ability to hold or release the charge depending on how much light and darkness is applied to the Image Drum. A photocopier (also known as a copier or copy machine) is a machine that makes paper copies of documents and other visual images quickly and cheaply. Most current photocopiers use a technology called xerography, a dry process using heat. Copiers can also use other technologies such as ink jet, but xerography is standard for office copying.

Answer is Option (1) for SSC Section Officer Physics MCQ

The energy 1 kilowatt-hour (kWh) is 3600000 joules or 3.6 mega joule. In physics, energy is an indirectly observed quantity that is often understood as the ability of a physical system to do work on other physical systems. However, this must be understood as an overly simplified definition, as the laws of thermodynamics demonstrate that not all energy can perform work.

Answer is Option (3) for SSC Section Officer Physics MCQ

On the surface of the Earth, the escape velocity is about 11.2 kilometers per second (~6.96 mi/s), which is approximately 34 times the speed of sound (Mach 34) and several times the muzzle velocity of a rifle bullet (up to 1.7 km/s). However, at 9,000 km altitude in “space”, it is slightly less than 7.1 km/s. In physics, escape velocity is the speed at which the kinetic energy plus the gravitational potential energy of an object is zero. It is the speed needed to “break free” from a gravitational field without further propulsion. A rocket moving out of gravity well does not actually need to attain escape velocity to do so, but could achieve the same result at any speed with a suitable mode of propulsion and sufficient fuel. Escape velocity only applies to ballistic trajectories.

Answer is Option (2) for SSC Section Officer Physics MCQ

We see rainbows because of the geometry of raindrops. When the sun shines from behind us into the rain, incident rays of light enter the drop and are refracted inwards. They are reflected from the back surface of the raindrop, and refracted again as they exit the raindrop and return to our eyes. A rainbow is an optical and meteorological phenomenon that is caused by reflection of light in water droplets in the Earth’s atmosphere, resulting in a spectrum of light appearing in the sky.

Answer is Option (4) for SSC Section Officer Physics MCQ

77-78 calories are released in a large size boiled egg. Boiled eggs are eggs (typically chicken eggs) cooked by immersion in boiling water with their shells unbroken.

Answer is Option (3) for SSC Section Officer Physics MCQ

Sound is a sequence of waves of pressure that propagates through compressible media such as air or water. (Sound can propagate through solids as well, but there are additional modes of propagation). Sound that is perceptible by humans has frequencies from about 20 Hz to 20,000 Hz. In air at standard temperature and pressure, the corresponding wavelengths of sound waves range from 17 m to 17 mm. During propagation, waves can be reflected, refracted, or attenuated by the medium. Now if we consider these cases, then the train which is arriving towards us having whistles of higher pitch because it propagates through a medium which is coming towards us but the train which is leaving propagating trough a medium moving further away from the listener and thus produced whistle of lower pitch.

Answer is Option (4) for SSC Section Officer Physics MCQ

Holography is a technique which enables three dimensional images to be made. It involves the use of a laser, interference, diffraction, light intensity recording and suitable illumination of the recording. The image changes as the position and orientation of the viewing system changes in exactly the same way as if the object were still present, thus making the image appear three-dimensional. The holographic recording itself is not an image; it consists of an apparently random structure of varying intensity, density or profile. Holography is a technique that enables a light field, which is generally the product of a light source scattered off objects, to be recorded and later reconstructed when the original light field is no longer present, due to the absence of the original objects.

Answer is Option (2) for SSC Section Officer Physics MCQ

It is just because woolen clothes have fibres and between those fibres air is trapped which reduces heat loss. Air reduces heat loss because it is an insulator or poor conductor of heat. Wool has several qualities that distinguish it from hair or fur: it is crimped, it is elastic, and it grows in staples (clusters). Wool’s scaling and crimp make it easier to spin the fleece by helping the individual fibers attach to each other, so they stay together. Because of the crimp, wool fabrics have a greater bulk than other textiles, and retain air, which causes the product to retain heat.

Answer is Option (4) for SSC Section Officer Physics MCQ

The time period ‘T’ of a simple pendulum is given by \(\displaystyle T=2\pi \sqrt{{\frac{l}{g}}}\), where l is the length and g is the acceleration due to gravity. Let us suppose g be to be a constant, then T = 2π √ 1. So the time period of a pendulum is directly proportional to the square root of its length. So, if the length increases, its time period also increase. It means that it takes longer to complete one oscillation. So when its length is halved, its time period is decreased by a factor of √2 .

Answer is Option (3) for SSC Section Officer Physics MCQ

Mist is a phenomenon caused by small droplets of water suspended in air. It can occur as part of natural weather or volcanic activity, and is common in cold air above warmer water, in exhaled air in the cold, and in a steam room of a sauna. It can also be created artificially with aerosol canisters if the humidity conditions are right. The only difference between mist and fog is visibility. Mist usually occurs near the shores, and is often associated with fog. Mist can be as high as mountain tops when extreme temperatures are low. Freezing mist is similar to freezing fog, only the density is less and the visibility greater.

Answer is Option (2) for SSC Section Officer Physics MCQ

A cricketer lowers his hands while taking a catch to decrease the rate of momentum. Cricketers increase the time by pulling their hand’s backward with the ball while taking a catch. Linear momentum or translational momentum is the product of the mass and velocity of an object. For example, a heavy truck moving fast has a large momentum—it takes a large and prolonged force to get the truck up to this speed, and it takes a large and prolonged force to bring it to a stop afterwards. If the truck were lighter, or moving slower, then it would have less momentum.

Answer is Option (2) for SSC Section Officer Physics MCQ

In summer, when the barometer falls suddenly, a thunderstorm can be expected, and if it does not rise again upon its cessation, the weather will probably continue unsettled for several days. In summer, when a thunderstorm happens, there is little or no depression of the barometer.

Answer is Option (2) for SSC Section Officer Physics MCQ

If a particle dropped from the top of a tower uniformly falls on ground at a distance which is equal to the height of tower, then a parabolic path will be traversed by a particle because when the particle is dropped that point is called the point of projection and when it reaches the ground that point is called the point of impact. Now, if the two points is met with one another the curve emerges is parabolic in nature. Hence, we can say that the path followed by the particle is of parabolic trajectories.

Answer is Option (2) for SSC Section Officer Physics MCQ

The sky is blue because the molecules in the air scatter light in the higher wavelengths (that is, the blue light), while lower wavelength light (that is, the light on the red end of the spectrum) goes through to the ground. So, the light that get finally reflected down from the scattering is blue, therefore a blue sky. This is called Rayleigh scattering. Rayleigh scattering, named after the British physicist Lord Rayleigh, is the elastic scattering of light or other electromagnetic radiation by particles much smaller than the wavelength of the light. The particles may be individual atoms or molecules. It can occur when light travels through transparent solids and liquids, but is most prominently seen in gases.

Answer is Option (2) for SSC Section Officer Physics MCQ

A dynamo is a device for converting mechanical energy into electrical energy, esp. one that produces direct current. A dynamo is an electrical generator that produces direct current with the use of a commutator. Dynamos were the first electrical generators capable of delivering power for industry, and the foundation upon which many other later electric-power conversion devices were based, including the electric motor, the alternating-current alternator, and the rotary converter. A dynamo has the disadvantages of a mechanical commutator. Also, converting alternating to direct current using power rectification devices (vacuum tube or more recently solid state) is effective and usually economic.

Answer is Option (4) for SSC Section Officer Physics MCQ

It is because of the capillary action phenomenon because of which oil rise up the wick in a lamp. Capillary action, or capillarity, is the ability of a liquid to flow in narrow spaces without the assistance of, and in opposition to external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paintbrush, in a thin tube, in porous materials such as paper, in some non-porous materials such as liquefied carbon fiber, or in a cell. It occurs because of inter-molecular attractive forces between the liquid and solid surrounding surfaces.

Answer is Option (1) for SSC Section Officer Physics MCQ

Most of the ultraviolet radiation in sunlight is absorbed by oxygen in Earth’s atmosphere, which forms the ozone layer of the lower stratosphere. UV light is found in sunlight (where it constitutes about 10% of the energy in vacuum) and is emitted by electric arcs and specialized lights such as black lights. It can cause chemical reactions, and causes many substances to glow or fluoresce. Most ultraviolet is classified as non-ionizing radiation. The higher energies of the ultraviolet spectrum from wavelengths about 10 nm to 120 nm (‘extreme’ ultraviolet) are ionizing, but this type of ultraviolet in sunlight is blocked by normal di-oxygen in air, and does not reach the ground. In addition to short wave UV blocked by oxygen, a great deal (>97%) of mid-range ultraviolet (almost all UV above 280 nm and most above 315 nm) is blocked by the ozone layer, and like ionizing short wave UV, would cause much damage to living organisms if it penetrated the atmosphere.

Answer is Option (4) for SSC Section Officer Physics MCQ

Respiration does not rely on the sun, so it is possible for plants to respire around the clock. The rate of respiration is dependent on temperature: The warmer it is, the more a plant will respire. Drought, extreme winter or frost and heat injury all create a situation for the plant where moisture is not adequate to maintain the proper water levels in plant tissues. Extreme winter cold and frost are similar to summer drought in that frozen water is unavailable to the plant. The air is very dry as well.

Answer is Option (2) for SSC Section Officer Physics MCQ

Displacement-time graph is non linear. Linear motion (also called rectilinear motion) is motion along a straight line, and can therefore be described mathematically using only one spatial dimension. The linear motion can be of two types: uniform linear motion with constant velocity or zero acceleration; non uniform linear motion with variable velocity or non-zero acceleration. The motion of a particle (a point like object) along a line can be described by its position, which varies with (time). An example of linear motion is an athlete running 100m along a straight track. Linear motion is the most basic of all motion.

Answer is Option (4) for SSC Section Officer Physics MCQ

Infrared imaging is used extensively for military and civilian purposes. Military applications include target acquisition, surveillance, night vision, homing and tracking. Non-military uses include thermal efficiency analysis, environmental monitoring, industrial facility inspections, remote temperature sensing, short-ranged wireless communication, spectro-scopy, and weather forecasting. Infrared astronomy uses sensor-equipped telescopes to penetrate dusty regions of space, such as molecular clouds; detect objects such as planets, and to view highly red-shifted objects from the early days of the universe. There are two main types of remote sensing: passive remote sensing and active remote sensing. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography, infrared, charge-coupled devices, and radiometers.

Answer is Option (3) for SSC Section Officer Physics MCQ

Changes in weather involve air movements, formation of clouds, and precipitation. Energy is needed to make all these things happen. That energy comes from the sun. Heat energy enters and moves through the atmosphere in three different ways. One way that heat energy is transferred is radiation. Hot bodies such as the sun radiate their energy mainly in the form of short waves. These short waves are seen as visible light. Cooler bodies such as Earth radiate their energy as longer waves.

Answer is Option (2) for SSC Section Officer Physics 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. Physically, rectifiers take a number of forms, including vacuum tube diodes, mercury-arc valves, solid-state diodes, silicon-controlled rectifiers and other silicon-based semiconductor switches. Rectifiers have many uses, but are often found serving as components of DC power supplies and high-voltage direct current power transmission systems. Rectification may serve in roles other than to generate direct current for use as a source of power.

Answer is Option (1) for SSC Section Officer Physics MCQ

The electromagnetic spectrum is the name we use when we talk about different types of radiation as a group. The parts of the electromagnetic spectrum, arranged from highest energy to lowest, are gamma rays, X-rays, ultraviolet light, visible light, infrared light, microwaves, and radio waves. All the parts of the electromagnetic spectrum are the same thing — radiation. Radiation is made up of a stream of photons — particles without mass that move in a wave pattern, all at the same speed — the speed of light. Each photon contains a certain amount of energy. The only difference between the parts of the electromagnetic spectrum is the amount of energy the photons contain. Radio waves have the least energy, and gamma rays have the most.

Answer is Option (1) for SSC Section Officer Physics MCQ

With metals, there are plenty of mobile carriers, and the motion of the lattice atoms due to thermal energy causes them to interfere with the transport of mobile carriers through the lattice. With semiconductors, there are insufficient mobile carriers at low temperatures and resistance is high. But as one heats the material, more and more of the lightly bound carriers escape and become free to conduct.

It should be noted that once all the soon-to-be-mobile carriers in a semiconductor are fully activated, it then behaves like a ‘metal’ and further temperature increases will cause it to reduce conductivity.

Answer is Option (1) for SSC Section Officer Physics MCQ

Sir Isaac Newton brought out his monograph, titled ‘Philosophiæ Naturalis Principia Mathematica,’ in 1687. In this work, Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, by demonstrating the consistency between Kepler’s laws of planetary motion and his theory of gravitation, thus removing the last doubts about helio-centrism and advancing the Scientific Revolution. Newton’s law of universal gravitation states that every point mass in the universe attracts every other point mass with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between them.

Answer is Option (3) for SSC Section Officer Physics MCQ

A lightning rod is a metal rod or metallic object mounted on top of a building, electrically bonded using a wire or electrical conductor to interface with ground or “earth” through an electrode, engineered to protect the building in the event of lightning strike. If lightning targets the building it will preferentially strike the rod and be conducted to ground through the wire, instead of passing through the building, where it could start a fire or cause electrocution. Copper and its alloys are the most common materials used in lightning protection. Copper does not attract lightning, but it effectively and rapidly facilitates the transmission of lightning energy to the ground because of its excellent electrical conductivity and corrosion resistance characteristics. Also, it bends easily compared to other conductor materials.

Answer is Option (3) for SSC Section Officer Physics MCQ

A hydrogen atom is very light. Most of the air on earth is made up of nitrogen, oxygen, and carbon dioxide. All of these elements are heavier than hydrogen, so the balloon is pushed upwards. Hydrogen weighs 0.08988 grams per liter. Nitrogen, which makes up 80% of the air we breathe, weighs 1.2506 grams per liter. Hydrogen filled balloons follow the same principle as we do when we float in the water; the law of buoyancy. If the water we displace weighs more than we do, we will float.

Answer is Option (3) for SSC Section Officer Physics MCQ

In electricity, a battery is a device consisting of one or more electrochemical cells that convert stored chemical energy into electrical energy. A battery is a device that converts chemical energy directly to electrical energy. It consists of a number of voltaic cells; each voltaic cell consists of two half-cells connected in series by a conductive electrolyte containing anions and cations. One half-cell includes electrolyte and the electrode to which anions (negatively charged ions) migrate, i.e., the anode or negative electrode; the other half-cell includes electrolyte and the electrode to which cations (positively charged ions) migrate, i.e., the cathode or positive electrode. In the redox reaction that powers the battery, cations are reduced (electrons are added) at the cathode, while anions are oxidized (electrons are removed) at the anode.

Answer is Option (4) for SSC Section Officer Physics MCQ

AM broadcasting is the process of radio broadcasting using amplitude modulation. AM was the first method of impressing sound on a radio signal and is still widely used today. An AM receiver detects amplitude variations in the radio waves at a particular frequency. It then amplifies changes in the signal voltage to drive a loudspeaker or earphones. The earliest crystal radio receivers used a crystal diode detector with no amplification.

Answer is Option (1) for SSC Section Officer Physics MCQ

Complementary colours are pairs of colours that are of “opposite” hue in some colour model. In colour theory, two colours are called complementary if, when mixed in the proper proportion, they produce a neutral colour (grey, white, or black). In roughly-perceptual colour models, the neutral colours (white, grey, and black) lie along a central axis. In the RGB colour model (and derived models such as HSV), primary colours and secondary colours are paired in this way: red and cyan; green and magenta; blue and yellow.

Answer is Option (2) for SSC Section Officer Physics MCQ

Indigo is a dye different than any other. It does not require any mordant. Rather it is dyed through a living fermentation process. The process “reduces” the Indigo, changing it from blue to yellow. In this state, it dissolves in an alkaline solution. The fibre is worked in the solution, or “vat”. When brought out to the air, it is a bright green. Slowly the air changes it to the beautiful deep and rich blue of Indigo.

Answer is Option (3) for SSC Section Officer Physics MCQ

In physics, elasticity is a physical property of materials which return to their original shape after the stress that caused their deformation is no longer applied. For very small deformations, most elastic materials, such as springs, exhibit linear elasticity. This means that they are characterized by a linear relationship between stress and strain (the relative amount of deformation). To describe elastic properties of linear objects like wires, rods, or columns which are stretched or compressed, a convenient parameter is the ratio of the stress to the strain, a parameter called the “Young’s modulus” or “Modulus of Elasticity” of the material. Young’s modulus can be used to predict the elongation or compression of an object as long as the stress is less than the yield strength of the material. Among rubber, steel, wet clay and plastic; steel has the maximum elasticity ranging between 180-200 gpa.

Answer is Option (4) for SSC Section Officer Physics MCQ

We need light to see what is around us and to see colour. Light bounces off the objects we look at. These reflect different amounts of light which we see as different colours. Our eyes need light to work. Light entering the eye is collected by the retina and processed by the brain to obtain the pictures that we need to see. Light is an essential part of this process, for example it is difficult to read when light levels are low. Sometimes light can cause problems for our vision. Usually our eyes adjust to the new source of light and we are able to see clearly again after a few seconds. The eye adjusts to the new level of light by making our pupil smaller (constricting). When a person walking in bright light enters a dark room, he is not able to see clearly because the iris is unable to dilate the pupil immediately. This phenomenon is called as photophobia.

Answer is Option (3) for SSC Section Officer Physics MCQ

The main theory of swing bowling surrounded turbulent and laminar airflow. Laminar air separates from the surface of the ball earlier than turbulent flow air, so that the separation point moves toward the front of the ball on the laminar side. On the turbulent flow side it remains towards the back; inducing a greater lift force on the turbulent airflow side of the ball. The calculated net lift force is not enough to account for the amount of swing observed: Additional force is provided by the pressure-gradient force.

Answer is Option (1) for SSC Section Officer Physics MCQ

In classical electromagnetism, magneti-zation or magnetic polari-zation is the vector field that expresses the density of permanent or induced magnetic dipole moments in a magnetic material. The origin of the magnetic moments responsible for magnetization can be either microscopic electric currents resulting from the motion of electrons in atoms, or the spin of the electrons or the nuclei. In the process of magnetization of a bar, the entire bulk of the bar gets magnetized. The magnetization of a material is done by electric current. By the process of magnetization, the formed pieces develop North polarity on one end or side and South polarity on the other end or side, in a very short period of time.

Answer is Option (2) for SSC Section Officer Physics MCQ

Raindrops start out as round high in the atmosphere as water collects on dust and smoke particles in clouds. But as raindrops fall, they lose their rounded shape. A raindrop falling through the atmosphere forms as a roughly spherical structure due to the surface tension of water. This surface tension is the “skin” of a body of water that makes the molecules stick together. The cause is the weak hydrogen bonds that occur between water molecules. On smaller raindrops, the surface tension is stronger than in larger drops. The reason is the flow of air around the drop. Air flow on the bottom of the water drop is greater than the airflow at the top.

Answer is Option (1) for SSC Section Officer Physics MCQ

In particle physics, fundamental interactions (sometimes called interactive forces or fundamental forces) are the ways that elementary particles interact with one another. An interaction is fundamental when it cannot be described in terms of other interactions. The four known fundamental interactions are electromagnetism, strong interaction (“strong nuclear force”), weak interaction (“weak nuclear force”), and gravitation. All are non-contact forces. Gravitation is by far the weakest of the four interactions. The weakness of gravity can easily be demonstrated by suspending a pin using a simple magnet (such as a refrigerator magnet). The magnet is able to hold the pin against the gravitational pull of the entire Earth.

Answer is Option (2) for SSC Section Officer Physics MCQ

The speed of sound in an ideal gas is independent of frequency, but it weakly depends on frequency for all real physical situations. It is a function of the square root of the absolute temperature, but is independent of pressure or density for a given ideal gas. Sound speed is slightly dependent on pressure only because air is not quite an ideal gas. In addition, for different gases, the speed of sound is inversely dependent on square root of the mean molecular weight of the gas, and affected to a lesser extent by the number of ways in which the molecules of the gas can store heat from compression, since sound in gases is a type of compression.

Answer is Option (2) for SSC Section Officer Physics MCQ

The density of gases depends upon the temperature. The higher the temperature, the more the molecules are spread out and the lower the density. The result is that warm gases rise and cool gases sink. The same concept helps to explain the weather resulting in high and low pressures. High pressure means high density, cooler, sinking air. Low pressure means low density, warmer, rising air. In general, density can be changed by changing either the pressure or the temperature.

Answer is Option (3) for SSC Section Officer Physics MCQ

Earthquakes, volcanic eruptions and other underwater explosions (including detonations of underwater nuclear devices), landslides, glacier calvings, meteorite impacts and other disturbances above or below water all have the potential to generate a tsunami. Tsunami can be generated when the sea floor abruptly deforms and vertically displaces the overlying water. Tectonic earthquakes are a particular kind of earthquake that are associated with the Earth’s crustal deformation; when these earthquakes occur beneath the sea, the water above the deformed area is displaced from its equilibrium position. More specifically, a tsunami can be generated when thrust faults associated with convergent or destructive plate boundaries move abruptly, resulting in water displacement, owing to the vertical component of movement involved.

Answer is Option (1) for SSC Section Officer Physics MCQ

Photosynthesis, process by which green plants and certain other organisms use the energy of light to convert carbon dioxide and water into the simple sugar glucose. The wavelength most effective in conducting photosynthesis is 420nm. Actually, 420nm is on the blue side of the spectrum, which makes up between 1 and 10% of the light needed for photosynthesis. There is a plateau on the blue side when comparing blue wavelength effects on photosynthesis, and 420nm is right on the edge of it. 430nm would be more in the middle of the plateau, making it the safer bet. Plants need red light, and lots of it. Red light contributes to over 90% of photosynthesis.

Answer is Option (2) for SSC Section Officer Physics MCQ

If C is the temperature in Celsius and F is the temperature in Fahrenheit then, C/S = (F – 32)/9. They are equal at -40° (minus 40 degrees), because if we convert the readings of Celsius and Fahrenheit, we will have: Celsius to Fahrenheit (-40°C x 9/5) +32 = -72 + 32 = -40°F. Fahrenheit to Celsius (-40°F – 32°) x 5/9 = (-72) x 5/9 = -40°C.

Answer is Option (2) for SSC Section Officer Physics MCQ

An anemometer is a device for measuring wind speed, and is a common weather station instrument. The first known description of an anemometer was given by Leon Battista Alberti around 1450.

Answer is Option (4) for SSC Section Officer Physics MCQ

The specific heat of water is 1 calorie/gram °C = 4.186 joule/gram °C which is higher than any other common substance. As a result, water plays a very important role in temperature regulation.

Answer is Option (3) for SSC Section Officer Physics MCQ

Copper ; 9% less conductive than silver; aluminium is 10% less conductive than copper; while steel is the least conductive among the given options. The most electrically conductive metal is silver.

Answer is Option (2) for SSC Section Officer Physics MCQ

Ordinary evaporation is a surface phenomenon – since the vapor pressure is low and since the pressure inside the liquid is equal to atmospheric pressure plus the liquid pressure, bubbles of water vapor cannot form. But at the boiling point, the saturated vapor pressure is equal to atmospheric pressure, bubbles form, and the vaporization becomes a volume phenomena.

Answer is Option (3) for SSC Section Officer Physics MCQ

Heavy water is used in certain types of nuclear reactors where it acts as a neutron moderator to slow down neutrons so that they are more likely to react with the fissile uranium-235 than with uranium-238 which captures neutrons without fissioning. Because they do not require uranium enrichment, heavy water reactors are of concern in regards to nuclear proliferation.

Answer is Option (2) for SSC Section Officer Physics MCQ

Tear gas is a compound. Each molecule of tear gas contains one atom of chlorine. The compound 2- chlorobenzalmalononitrile, a cyanocarbon, is the defining component of a “tear gas” commonly referred to as CS gas, which is used as a riot control agent.