Answer is Option (2) for the Physics MCQ

The refractive index of many materials (such as glass) varies with the wavelength or colour of the light used, a phenomenon known as dispersion. This causes light of different colours to be refracted differently and to leave the prism at different angles, creating an effect similar to a rainbow. In optics, dispersion is the phenomenon in which the phase velocity of a wave depends on its frequency, or alternatively when the group velocity depends on the frequency. Media having such a property are termed dispersive media. Dispersion is sometimes called chromatic dispersion to emphasize its wavelengthdependent nature, or group-velocity dispersion (GVD) to emphasize the role of the group.

Answer is Option (2) for the SSC CGL Physics MCQ

A boat will float when the weight of the water it displaces equals the weight of the boat and anything will float if it is shaped to displace its own weight of water before it reaches the point where it will submerge. Floating of the boat works on the principle of buoyancy force which is an upward force exerted by a liquid, gas or other fluid, that opposes the weight of an immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus a column of fluid, or an object submerged in the fluid, experiences greater pressure at the bottom of the column than at the top. This difference in pressure results in a net force that tends to accelerate an object upwards.

Answer is Option (3) for the Physics MCQ

Surface tension is a contractive tendency of the surface of a liquid that allows it to resist an external force. This property is caused by cohesion of similar molecules, and is responsible for many of the behaviors of liquids. 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.

Answer is Option (3) for the Physics MCQ for SSC CGL

In the late of 17th century British scientist Isaac Newton studied cooling of bodies. Experiments showed that the cooling rate is approximately proportional to the difference of temperatures between the heated body and the environment. This fact can be written as the differential relation : \(\displaystyle \frac{{dQ}}{{dt}}=\alpha A({{T}_{s}}-T)\), where A is the surface area of the body through which the heat is transferred, T is the temperature of the body, \(\displaystyle {{T}_{s}}\) is the temperature of the surrounding environment, á is the heat transfer coefficient depending on the geometry of the body, state of the surface, heat transfer mode, and other factors. Surface area or volume ratio is an important influence on temperature control. For same volume sphere has minimum surface area, while circular plate has maximum surface area. So sphere cools slowest and plate cools fastest.

Answer is Option (4) for the Physics MCQ

Optical fibres are used in endoscopic instruments that enable doctors to view internal body parts without having to perform surgery. Fernando Alves Martins of Portugal invented the first fiber optic endoscope in 1963-64. Further innovations included using additional fibres to channel light to the objective end from a powerful external source, thereby achieving the high level of full spectrum illumination that was needed for detailed viewing, and colour photography. The previous practice of a small filament lamp on the tip of the endoscope had left the choice of either viewing in a dim red light or increasing the light output – which carried the risk of burning the inside of the patient. Alongside the advances to the optical side, the ability to ‘steer’ the tip was developed, as well as innovations in remotely operated surgical instruments contained within the body of the endoscope itself. This was the beginning of “key-hole surgery” as we know it today.

Answer is Option (1) for the SSC CGL Physics MCQ

Since the amplitudes, frequency and the speed of both the waves are in same, hence the wavelength of the composite wave will be the same as the single wave. The distance between the adjacent nodes will be \(\displaystyle \frac{\alpha }{2}\), Speed of the wave, i.e., V = nλ. Or, 20 = 10λ. So, λ = 2 mm. Therefore, \(\displaystyle \frac{\alpha }{2}\) = 1 mm

Answer is Option (2) for the Physics MCQ

Newly formed snow reflects about 90 per cent of the sunlight that falls upon it. This means that the sun is powerless to melt clean snow. And when snow does melt, it is not because of the sunlight. Snow does not melt on a spring day because of the sun’s heat. It melts because of the warm air from the sea.

Answer is Option (1) for the Physics MCQ

The density of dry air is more than that of moist air (when moisture is removed from air, its density increases). The speed of sound in a medium is inversely proportional to the square root of its density. Therefore, the speed of sound in moist air is more than that in dry air.

Answer is Option (1) for the Physics MCQ for SSC CGL

Curie, in physics, unit of activity of a quantity of a radioactive substance, named in honour of the French physicist Marie Curie. One curie (1 Ci) is equal to 3.7 × \(\displaystyle {{10}^{{10}}}\) becquerel (Bq). Radioactivity refers to the particles which are emitted from nuclei as a result of nuclear instability. Because the nucleus experiences the intense conflict between the two strongest forces in nature, it should not be surprising that there are many nuclear isotopes which are unstable and emit some kind of radiation. The most common types of radiation are called alpha, beta, and gamma radiation, but there are several other varieties of radioactive decay.

Answer is Option (3) for the Physics MCQ for SSC CGL

An oven that uses micro radiation waves as a source of heat in order to cook food as opposed to a fire source. Conceptualized in 1946, Dr. Perry Spencer allegedly discovered the heating properties of microwaves while studying the magnetron. A microwave oven, often colloquially shortened to microwave, is a kitchen appliance that heats food by dielectric heating accomplished with radiation used to heat polarized molecules in food. Microwave ovens heat foods quickly and efficiently because excitation is fairly uniform in the outer 25–38 mm of a dense (high water content) food item; food is more evenly heated throughout (except in thick, dense objects) than generally occurs in other cooking techniques. A microwave oven works by passing non-ionizing microwave radiation, usually at a frequency of 2.45 gigahertz (GHz)—a wavelength of 122 millimetres (4.80 in)—through the food. Microwave radiation is between common radio and infrared frequencies.

Answer is Option (4) for the Physics MCQ

When heated from 0⁰ to 10⁰ C volume of a given mass of water will first decrease and then increase. If the word “ice” or “solid” is not mentioned, the word “water” means liquid water. Water vapor can be produced from the evaporation or boiling of liquid water. So the volume first decreases and then increases again when water droplets form from the vapours due to stoppage of heat.

Answer is Option (1) for the SSC CGL Physics MCQ

The central mass of the sun becomes increasingly hot and dense, eventually initiating thermonuclear fusion in its core. It is thought that almost all other stars form by this process. nuclear fusion is a nuclear reaction in which two or more atomic nuclei join together, or “fuse”, to form a single heavier nucleus. During this process, matter is not conserved because some of the mass of the fusing nuclei is converted to energy which is released. Fusion is the process that powers active stars. The fusion of two nuclei with lower masses than iron (which, along with nickel, has the largest binding energy per nucleon) generally releases energy, while the fusion of nuclei heavier than iron absorbs energy.

Answer is Option (3) for the Physics MCQ for SSC CGL

An LC circuit, also called a resonant circuit, tank circuit, or tuned circuit, consists of an inductor, represented by the letter L, and a capacitor, represented by the letter C. When connected together, they can act as an electrical resonator, an electrical analogue of a tuning fork, storing energy oscillating at the circuit’s resonant frequency. When connected together, they can act as an electrical resonator; an electrical analogue of a tuning fork, storing energy oscillating at the circuit’s resonant frequency. An LC circuit is an idealized model since it assumes there is no dissipation of energy due to resistance.

Answer is Option (3) for the Physics MCQ

X-rays are part of the electromagnetic spectrum, an ionizing radiation with wavelengths shorter than ultraviolet light. X-ray tubes evolved from experimental Crookes tubes with which X-rays were first discovered in the late 19th century, and the availability of this controllable source of X-rays created the field of radiography, the imaging of opaque objects with penetrating radiation.

Answer is Option (1) for the Physics MCQ

The Zener diode is like a general-purpose signal diode. When based in the forward direction it behaves just like a normal signal diode, but when a reverse voltage is applied to it, the voltage remains constant for a wide range of currents and hence widely used for regulated electric supply. The device was named after Clarence Zener, who discovered this electrical property. Many diodes described as “Zener” diodes rely instead on avalanche breakdown as the mechanism. Common applications include providing a reference voltage for voltage regulators, or to protect other semiconductor devices from momentary voltage pulses. Zener diodes are widely used as voltage references and as shunt regulators to regulate the voltage across small circuits.

Answer is Option (1) for the SSC CGL Physics MCQ

Colour or color is the visual perceptual property corresponding in humans to the categories called red, green, blue, and others. Colour derives from the spectrum of light (distribution of light power versus wavelength) interacting in the eye with the spectral sensitivities of the light receptors. Colour categories and physical specifications of colour are also associated with objects, materials, light sources, etc., based on their physical properties such as light absorption, reflection, or emission spectra. By defining a colour space, colours can be identified numerically by their coordinates.

Answer is Option (3) for the Physics MCQ for SSC CGL

Hydraulic brakes work on the principle of Pascal’s law which states that “pressure at a point in a fluid is equal in all directions in space”. According to this law when pressure is applied on a fluid it travels equally in all directions so that uniform braking action is applied on all four wheels. The hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing ethylene glycol, to transfer pressure from the controlling unit, which is usually near the operator of the vehicle, to the actual brake mechanism, which is usually at or near the wheel of the vehicle.

Answer is Option (2) for the Physics MCQ

Since mercury is 13+ times as dense as water, a given volume of mercury would carry about 4.4 times as much heat, so mercury is best conductor of heat among the given options. It is the only metal that is liquid at standard conditions for temperature and pressure. Mercury has one of the narrowest ranges of its liquid state of any metal. Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, It is used in lighting: electricity passed through mercury vapor in a fluorescent lamp produces shortwave ultraviolet light which then causes the phosphor in the tube to fluoresce, making visible light.

Answer is Option (2) for the Physics MCQ for SSC CGL

Electron microscopes are used to observe a wide range of biological and inorganic specimens including microorganisms, cells, large molecules, biopsy samples, metals, and crystals. An electron microscope uses a beam of electrons to illuminate a specimen and produce a magnified image. An electron microscope (EM) has greater resolving power than a light-powered optical microscope because electrons have wavelengths about 100,000 times shorter than visible light photons. The electron microscope uses electrostatic and electromagnetic “lenses” to control the electron beam and focus it to form an image. Industrially, the electron microscope is often used for quality control and failure analysis.

Answer is Option (2) for the SSC CGL Physics MCQ

Sonar (originally an acronym for Sound Navigation And Ranging) is a technique that uses sound propagation (usually underwater, as in submarine navigation) to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels. Two types of technology share the name “sonar”: passive sonar is essentially listening for the sound made by vessels; active sonar is emitting pulses of sounds and listening for echoes. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of “targets” in the water.

Answer is Option (2) for the Physics MCQ

The instrument which uses sound waves to measure the depth of oceans is sonar. Sound waves can travel much faster from one point to another. Sound waves are far more accurate for measuring these vast distances. Sonar may be used as a means of acoustic location and of measurement of the echo characteristics of “targets” in the water. Sonar may also be used in air for robot navigation, and SODAR is used for atmospheric investigations.

Answer is Option (1) for the Physics MCQ for SSC CGL

It is widely accepted that the first prototype of an electron microscope was built by Ernst Ruska and Max Knoll in 1931; it was not more powerful than an optical microscope, but it demonstrated the principle that is still used in today’s sophisticated and powerful instruments, and earned its builders a share of a Nobel Prize. An electron microscope uses a beam of electrons to illuminate a specimen and produce a magnified image. An electron microscope (EM) has greater resolving power than a light-powered optical microscope because electrons have wavelengths about 100,000 times shorter than visible light photons. The electron microscope uses electrostatic and electromagnetic “lenses” to control the electron beam and focus it to form an image.

Answer is Option (3) for the Physics MCQ

Diffusion is one of several transport phenomena that occur in nature. A distinguis-hing feature of diffusion is that it results in mixing or mass transport without requiring bulk motion. Thus, diffusion should not be confused with convection or advection, which are other transport mechanisms that use bulk motion to move particles from one place to another. From the atomistic point of view, diffusion is considered as a result of the random walk of the diffusing particles. In molecular diffusion, the moving molecules are self-propelled by thermal energy.

Answer is Option (3) for the Physics MCQ

Cloudless nights are colder because the nights that have clouds provide a blanket for the earth and trap some of the hot day air where as the cloudless nights have no protection so all the hot air rises up into the sky. radiation is a process in which energetic particles or energetic waves travel through vacuum, or through matter-containing media that are not required for their propagation. Waves of a massive medium itself, such as water waves or sound waves, are usually not considered to be forms of “radiation” in this sense. By contrast, gravitational waves, which are waves of space-time itself, qualify as a type of radiation.

Answer is Option (3) for the SSC CGL Physics MCQ

Sound travels faster in liquids and non-porous solids than it does in air. It travels about 4.3 times as fast in water (1,484 m/s), and nearly 15 times as fast in iron (5,120 m/s), than in air at 20 degrees Celsius. Sound waves in solids are composed of compression waves (just as in gases and liquids), but also exhibit a different type of sound wave called a shear wave, which occurs only in solids. The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at 20 °C (68 °F), the speed of sound is 343.2 metres per second (1,126 ft/s). This is 1,236 kilometers per hour (768 mph), or about one kilometer in three seconds or approximately one mile in five seconds.

Answer is Option (4) for the Physics MCQ

Gas is easily compressed so it would have a more versatile range of measurement at least in our atmospheric conditions. Liquid is not so easily compressed, so, very little pressure via mass / gravity or heat would cause it to quickly jump between changes. A gas thermometer measures temperature by the variation in volume or pressure of a gas. One common apparatus is a constant volume thermometer. Gas thermometers are often used to calibrate other thermometers.

Answer is Option (3) for the Physics MCQ

A type of glass that contains cerium and other rare earths and has a high absorption of ultraviolet radiation is used in sunglasses. Sunglasses or sun glasses are a form of protective eyewear designed primarily to prevent bright sunlight and high-energy visible light from damaging or discomforting the eyes. They can sometimes also function as a visual aid, as variously termed spectacles or glasses exist, featuring lenses that are coloured, polarized or darkened. In the early 20th century they were also known as sun cheaters. The colour of the lens can vary depending on style, fashion, and purpose, but for general use, red, grey, green, or brown are recommended to avoid or minimize colour distortion, which could affect safety when, for instance, driving a car or a school bus.

Answer is Option (3) for the Physics MCQ for SSC CGL

The speed of light with the rise in the temperature of the medium remains unaltered because speed of light doesn’t depend on temperature. It does depend, however, on the refractive index of the substance it is travelling through. The speed of light in vacuum, commonly denoted c, is a universal physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact because the length of the metre is defined from this constant and the international standard for time.  

Answer is Option (4) for the 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. Hence, all the heat from our body gets trapped inside the clothes which makes us feels warmer with the clothes.

Answer is Option (4) for the Physics MCQ

Basically, refrigeration system consists of devices that compress and expand refrigerant gas . When refrigerant gas is compressed it expels heat and when it is suddenly expanded, absorbs heat. A refrigerator (colloquially fridge) is a common household appliance that consists of a thermally insulated compartment and a heat pump (mechanical, electronic, or chemical) that transfers heat from the inside of the fridge to its external environment so that the inside of the fridge is cooled to a temperature below the ambient temperature of the room. A vapor compression cycle is used in most household refrigerators, refrigerator– freezers and freezers. In this cycle, a circulating refrigerant such as R134a enters a compressor as low-pressure vapor at or slightly above the temperature of the refrigerator interior. The vapor is compressed and exits the compressor as highpressure superheated vapor. The superheated vapor travels under pressure through coils or tubes comprising the condenser, which are passively cooled by exposure to air in the room. The condenser cools the vapor, which liquefies. As the refrigerant leaves the condenser, it is still under pressure but is now only slightly above room temperature. This liquid refrigerant is forced through a metering or throttling device, also known as an expansion valve (essentially a pin-hole sized constriction in the tubing) to an area of much lower pressure.

Answer is Option (1) for the Physics MCQ

Shortwave radio is used for broadcasting of voice and music, and long-distance communication to ships and aircraft, or to remote areas out of reach of wired communication or other radio services and that’s why it is more energetic than long waves. Shortwave radio is radio communication using the upper MF (medium frequency) and all of the HF (high frequency) portion of the radio spectrum, between 1,800–30,000 kHz. Shortwave radio received its name because the wavelengths in this band are shorter than 200 m (1500 kHz) which marked the original upper limit of the medium frequency band first used for radio communications. The broadcast medium wave band now extends above the 200 m/1500 kHz limit, and the amateur radio 1.8 MHz – 2.0 MHz band (known as the “top band”) is the lowest-frequency band considered to be ‘shortwave’.

Answer is Option (3) for the SSC CGL Physics MCQ

The characteristics of plasmas are significantly different from those of ordinary neutral gases so that plasmas are considered a distinct “fourth state of matter. plasma is a state of matter similar to gas in which a certain portion of the particles is ionized. Heating a gas may ionize its molecules or atoms (reduce or increase the number of electrons in them), thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions. Ionization can be induced by other means, such as strong electromagnetic field applied with a laser or microwave generator, and is accompanied by the dissociation of molecular bonds, if presents.

Answer is Option (4) for the Physics MCQ

Lambert’s Law says that the intensity of emitted light from a surface is directly proportional to the cosine of the angle between the line of view and the normal to the surface. A Lambertian surface is a surface that follows this rule exactly. In practice, most surfaces are not perfectly Lambertian. A surface which obeys Lambert’s law is said to be Lambertian, and exhibits Lambertian reflectance. Such a surface has the same radiance when viewed from any angle. This means, for example, that to the human eye it has the same apparent brightness (or luminance). It has the same radiance because, although the emitted power from a given area element is reduced by the cosine of the emission angle, the apparent size (solid angle) of the observed area, as seen by a viewer, is decreased by a corresponding amount. Therefore, its radiance (power per unit solid angle per unit projected source area) is the same.

Answer is Option (3) for the Physics MCQ

The law of conservation of mass, also known as the principle of mass/matter conservation, states that the mass of an isolated system (closed to all transfers of matter and energy) will remain constant over time. This principle is equivalent to the conservation of energy: when energy or mass is enclosed in a system and none is allowed in or out, its quantity cannot otherwise change over time (hence, its quantity is “conserved” over time). The mass of an isolated system cannot be changed as a result of processes acting inside the system. The law implies that mass can neither be created nor destroyed, although it may be rearranged in space and changed into different types of particles; and that for any chemical process in an isolated system, the mass of the reactants must equal the mass of the products.

Answer is Option (3) for the Physics MCQ for SSC CGL

The decibel (abbreviated dB) is the unit used to measure the intensity of a sound. The decibel scale is a little odd because the human ear is incredibly sensitive. Our ears can hear everything from your fingertip brushing lightly over your skin to a loud jet engine. The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities. The decibel is used for a wide variety of measurements in science and engineering, most prominently in acoustics, electronics, and control theory.

Answer is Option (1) for the Physics MCQ

An isoneph is a line indicating equal cloud cover or equal cloudiness. Variations in the degrees of slope, temperature, occurrence of rainfall, may be represented by drawing the lines of equal values on a map. All such maps are termed as Isopleth Map. The word Isopleth is derived from ‘Iso’ meaning equal and ‘pleth’ means lines. Thus, an imaginary line, which joins the places of equal values, is referred as Isopleth. The more frequently drawn isopleths include Isotherm (equal temperature), Isobar (equal pressure), Isohyets (equal rainfall), Isonephs (equal cloudiness), Isohels (equal sunshine), contours (equal heights), Isobaths (equal depths), Isohaline (equal salinity), etc.

Answer is Option (2) for the SSC CGL Physics MCQ

The ionosphere is a part of the upper atmosphere, from about 85 km to 600 km altitude, comprising portions of the mesosphere, thermosphere and exosphere, distinguished because it is ionized by solar radiation. It plays an important part in atmospheric electricity and forms the inner edge of the magnetosphere. It has practical importance because, among other functions, it influences radio propagation to distant places on the Earth. The ionosphere is a shell of electrons and electrically charged atoms and molecules that surrounds the Earth, stretching from a height of about 50 km to more than 1000 km. It owes its existence primarily to ultraviolet radiation from the Sun.

Answer is Option (2) for the Physics MCQ for SSC CGL

Cryogenics is the study of how to get to low temperatures and of how materials behave when they get there. Besides the familiar temperature scales of Fahrenheit and Celsius (Centigrade), cryogenicists use other temperature scales, the Kelvin and Rankine temperature scales. One of the more modern processes being used to treat metals (as well as other materials) is cryogenic tempering. While the science of heat treatment is well known and widely understood, the principles of cryogenic tempering remain a mystery to most people in industry.

Answer is Option (4) for the SSC CGL Physics MCQ

Special theory of relativity postulates that the speed of light is a universal constant. We cannot reach speeds greater than the speed of light by the relativistic addition of velocities. The equation is how to reconcile with this result of special relativity with Newton’s second law, F=ma. It would be seen that any constant force, no matter how small, applied for a considerably very long time, should continuously accelerate any mass ‘m’ at a rate a=f/m until the speed was arbitrarily very large. Einstein, concluded that energy has inertia i.e. the more energy a body possess, the more inertia that body will display. Since, inertia is a property of matter, which is associated with mass. Thus from Einstein’s argument mass is simply a property attributed to the total energy of the body and only the total energy is required, to know the total mass of the body.

Answer is Option (3) for the Physics MCQ

An atomic clock is a clock device that uses an electronic transition frequency in the microwave, optical, or ultraviolet region of the electromagnetic spectrum of atoms as a frequency standard for its timekeeping element. Atomic clocks are the most accurate time and frequency standards known, and are used as primary standards for international time distribution services, to control the wave frequency of television broadcasts, and in global navigation satellite systems such as GPS.

Answer is Option (1) for the Physics MCQ

Astigmatism is an optical defect in which vision is blurred due to the inability of the optics of the eye to focus a point object into a sharp focused image on the retina. This may be due to an irregular or toric curvature of the cornea or lens. The two types of astigmatism are regular and irregular. Irregular astigmatism is often caused by a corneal scar or scattering in the crystalline lens, and cannot be corrected by standard spectacle lenses, but can be corrected by contact lenses. Regular astigmatism arising from either the cornea or crystalline lens can be corrected by a toric lens. This optical shape gives rise to regular astigmatism in the eye. Toric lens is somewhat similar in significance to cylindrical cells.

Answer is Option (2) for the Physics MCQ for SSC CGL

Superconductivity is a phenomenon of exactly zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature. It is characterized by the Meissner effect, the complete ejection of magnetic field lines from the interior of the superconductor as it transitions into the superconducting state. The electrical resistivity of a metallic conductor decreases gradually as temperature is lowered. In a superconductor, the resistance drops abruptly to zero when the material is cooled below its critical temperature. An electric current flowing in a loop of superconducting wire can persist indefinitely with no power source.

Answer is Option (4) for the SSC CGL Physics MCQ

In a Laser all the atoms emit the light waves of same frequency, amplitude and phase. A laser is a device that emits light (electromagnetic radiation) through a process of optical amplification based on the stimulated emission of photons. The term “laser” originated as an acronym for Light Amplification by Stimulated Emission of Radiation.

Answer is Option (2) for the Physics MCQ SSC CGL

Heat capacity (usually denoted by a capital C, often with subscripts), or thermal capacity, is the measurable physical quantity that characterizes the amount of heat required to change a substance’s temperature by a given amount. In the International System of Units (SI), heat capacity is expressed in units of joule(s) (J) per Kelvin (K). Among iron piece, water, gold piece and benzene; water has the maximum heat capacity i.e. 4.1813 j/g.k.

Answer is Option (2) for the Physics MCQ

Relative humidity is the ratio of the partial pressure of water vapor in an air-water mixture to the saturated vapor pressure of water at a prescribed temperature. The relative humidity of air depends not only on temperature but also on the pressure of the system of interest. If the system at State A is isobarically heated (heating with no change in system pressure) then the relative humidity of the system decreases because the saturated vapor pressure of water increases with increasing temperature.

Answer is Option (3) for the Physics MCQ

Fleming’s right hand rule shows the direction of induced current when a conductor moves in a magnetic field. The right hand is held with the thumb, first finger and second finger mutually perpendicular to each other. The rule is named after British engineer John Ambrose Fleming.

Answer is Option (3) for the SSC CGL Physics MCQ

Air is a good insulator. Therefore, we feel warmer as the heat can’t conduct away as easily. The reason layers work to keep us warm is that they form air pockets in between each layer which is insulated by our body heat. The more pocket of air we have, the more insulation we have, thus the warmer we are.

Answer is Option (1) for the Physics MCQ for SSC CGL

Long distance propagation of radio waves depends on an invisible layer of charged particles, which envelops the Earth. This layer of charged particles known as the ionosphere has been in existence for millions of years. For those, who pioneered the long distance radio communication during the early part of the twentieth century, the ionosphere came as a boon.

Answer is Option (4) for the Physics MCQ

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing. Sound also travels through plasma. 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 cannot travel through a vacuum because it does not provide the medium to propagate.

Answer is Option (4) for the Physics MCQ SSC CGL

Photocells are scientifically known as photoresistors. A photo-resistor or light dependent resistor (LDR) is a resistor whose resistance decreases with increasing incident light intensity; in other words, it exhibits photoconductivity. A photo-resistor is made of a high resistance semiconductor. If light falling on the device is of high enough frequency, photons absorbed by the semiconductor give bound electrons enough energy to jump into the conduction band. The resulting free electron conduct electricity, thereby lowering resistance. Photo-resistors are basically photocells.

Answer is Option (3) for the Physics MCQ SSC CGL

Atmospheric pressure is basically the weight of air in the atmosphere above the reservoir, so the level of mercury continues to change until the weight of mercury in the glass tube is exactly equal to the weight of air above the reservoir. In areas of low pressure, air is rising away from the surface of the earth more quickly than it can be replaced by air flowing in from surrounding areas. This reduces the weight of air above the reservoir so the mercury level drops to a lower level. A sudden drop in atmospheric pressure over a few hours often forecasts an approaching storm, with heavy rain and strong winds.

Answer is Option (3) for the SSC CGL Physics MCQ

Following the density principle, the density of the egg compared to the density of the tap water is lesser (the density principle states that an object or substance with lesser density will float on the surface of the substance or object which has the greater density). Now, with salt, salt makes the density of the tap water to increase and increases also the salinity of the water making the egg float because the density of the water with salt is now greater than the density of the egg and that is why an egg sinks in soft water but floats in a concentrated solution of salt.

Answer is Option (3) for the Physics MCQ

The answer is related to the conservation of angular momentum. The person on the rotating table will maintain approximately the same angular momentum during the spin. If he moves his arms in, it will reduce the rotational inertia by reducing the distance of the mass of her arms and hands from the axis of rotation. In order to maintain the same angular momentum, angular rotation is increased. However, when he spreads his hands outward, the angular rotation is decreased. The spin becomes slower.

Answer is Option (2) for the Physics MCQ

The Moon and other celestial bodies contain a vast amount of natural resources. One, and in abundance, is helium-3. It is estimated that forty tons of it can meet twenty five percent of the global energy demand for one year. This clean, nonradioactive and safe source of energy scarcely exist on Earth. Helium-3 derives from the dismantlement of old and outdated nuclear warheads. Helium-3 is used within medicine, scientific research, and well logging operations in the oil and gas industry, and for homeland security. Major space nations such as Russia, China, India, and Japan appear to have integrated within their space programmes to commercially exploit the Moon for helium-3 in the future.

Answer is Option (2) for the Physics MCQ SSC CGL

Concave lens possesses at least one surface that curves inwards. It is a diverging lens, spreading out those light rays that have been refracted through it. A concave lens is thinner at its centre than at its edges, and is used to correct short-sightedness (myopia). After light rays have passed through the lens, they appear to come from a point called the principal focus. The image formed by a concave lens is virtual, upright, and smaller than the object, and it cannot be projected onto a screen.

Answer is Option (3) for the Physics MCQ

In materials science, shear modulus or modulus of rigidity, denoted by G, or sometimes S , is defined as the ratio of shear stress to the shear strain. The shear modulus describes the material’s response to shearing strains (like cutting it with dull scissors).The shear modulus is concerned with the deformation of a solid when it experiences a force parallel to one of its surfaces while its opposite face experiences an opposing force (such as friction). In the case of an object that’s shaped like a rectangular prism, it will deform into a parallelepiped.

Answer is Option (1) for the SSC CGL Physics MCQ

Sound is a mechanical wave that is an oscillation of pressure transmitted through a solid, liquid, or gas, composed of frequencies within the range of hearing. During propagation, waves can be reflected, refracted, or attenuated by the medium. Sound is transmitted through gases, plasma, and liquids as longitudinal waves, also called compression waves. Through solids, however, it can be transmitted as both longitudinal waves and transverse waves. Longitudinal sound waves are waves of alternating pressure deviations from the equilibrium pressure, causing local regions of compression and rarefaction, while transverse waves (in solids) are waves of alternating shear stress at right angle to the direction of propagation.

Answer is Option (1) for the Physics MCQ

Heavy water, formally called deuterium oxide or 2\(\displaystyle {{H}_{2}}O\) or \(\displaystyle {{D}_{2}}O\), is a form of water that contains the hydrogen isotope deuterium, rather than the common protium isotope. The colloquial term heavy water is often also used to refer a highly enriched water mixture that contains mostly deuterium oxide but also contains some ordinary water molecules as well: for instance heavy water used in CANDU reactors is 99.75% enriched by hydrogen atom-fraction. In comparison, in ordinary water, there are only about 156 deuterium atoms per million hydrogen atoms). In its pure form, it has a density about 11% greater than water, but otherwise, is physically and chemically similar. Heavy water is 10.6% denser than ordinary water, a difference which is not immediately obvious.

Answer is Option (1) for the Physics MCQ SSC CGL

Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. The reactions involved in respiration are catabolic reactions, which break large molecules into smaller ones, releasing energy in the process as they break high-energy bonds. Respiration is one of the key ways a cell gains useful energy to fuel cellular activity. Chemically, cellular respiration is considered an exothermic redox reaction.

Answer is Option (4) for the Physics MCQ

The frequency of a full-wave rectifier is double that of the input, if the input is a sine wave. A fullwave rectifier converts the whole of the input waveform to one of constant polarity (positive or negative) at its output. Full-wave rectification converts both polarities of the input waveform to DC (direct current), and yields a higher mean output voltage. Two diodes and a centre tapped transformer, or four diodes in a bridge configuration and any AC source (including a transformer without center tap), are needed. Single semiconductor diodes, double diodes with common cathode or common anode, and four diode bridges, are manufactured as single components.

Answer is Option (4) for the SSC CGL Physics MCQ

Convection transfers heat vertically into the atmosphere. In order for heat to be transferred to other regions, it must be transferred horizontally by the wind. The horizontal transfer of heat by the wind is called advection. Advection is a transport mechanism of a substance or conserved property by a fluid due to the fluid’s bulk motion. An example of advection is the transport of pollutants or silt in a river by bulk water flow downstream.

Answer is Option (4) for the Physics MCQ SSC CGL

The decibel (dB) is a logarithmic unit that indicates the ratio of a physical quantity (usually power or intensity) relative to a specified or implied reference level. A ratio in decibels is ten times the logarithm to base 10 of the ratio of two power quantities.

63. The bats can fly in the dark because

(1) they can see the objects in darkness

(2) they have weak legs and are likely to be attacked by predators

(3) they generate flashes of light

(4) they generate ultrasonic sound waves

Show Answer

Answer is Option (4) for the Physics MCQ

Bats use echolocation to navigate and forage, often in total darkness. They generally emerge from their roosts in caves, attics, or trees at dusk and hunt for insects into the night. Their use of echolocation allows them to occupy a niche where there are often many insects (that come out at night since there are fewer predators then) and where there is less competition for food, and where there are fewer other species that may prey on the bats themselves. Microbats generate ultrasound via the larynx and emit the sound through the open mouth or, much more rarely, the nose.

Answer is Option (3) for the Physics MCQ

Fresh water cooled to zero (0) degree Celsius and subjected to additional loss of heat energy normally will freeze. A mixture of fresh water and ice has an equilibrium temperature of zero (0) degree Celsius. Adding heat to the mixture causes ice to melt whereas removing heat causes water to freeze. For that reason, 0 (zero) degree Celsius is called the freezing point of fresh water. Cloud droplets can cool well below the usual freezing point while remaining liquid. Such cloud droplets are composed of super cooled water.

Answer is Option (2) for the Physics MCQ SSC CGL

In physics and materials science, the Curie temperature (Tc), or Curie point, is the temperature at which a ferromagnetic or a ferromagnetic material becomes paramagnetic on heating; the effect is reversible. A magnet will lose its magnetism if heated above the Curie temperature. The term is also used in piezoelectric materials to refer to the temperature at which spontaneous polarization is lost on heating.

Answer is Option (1) for the SSC CGL Physics MCQ

The angle of repose or the critical angle of repose, of a granular material is the steepest angle of descent or dip of the slope relative to the horizontal plane when material on the slope face is on the verge of sliding. This angle is in the range 0°–90°.When bulk granular materials are poured onto a horizontal surface, a conical pile will form. The internal angle between the surface of the pile and the horizontal surface is known as the angle of repose and is related to the density, surface area and shapes of the particles, and the coefficient of friction of the material. For certain applications it is more useful to define static friction in terms of the maximum angle before which one of the items will begin sliding. This is called the angle of friction or friction angle. The tangent of the angle of friction is equal to the coefficient of friction. Angle of friction is equal to the angle of repose.

Answer is Option (2) for the Physics MCQ SSC CGL

Radiation is one of the byproducts of radioactive decay of unstable atomic nuclei. Nuclear fission is the process on which the operation of most nuclear power plants is based. When certain nuclei (for example that of uranium-235) are bombarded with neutrons, the nucleus splits into two smaller nuclei of roughly (though not exactly) equal sizes. Because of the binding characteristics of the neutrons and protons in the original and resultant nuclei (and also the famous mass-energy relation that Einstein discovered), the result of this split is the liberation of a large amount of energy, manifested in the kinetic energy of the resultant nuclei.

Answer is Option (4) for the SSC CGL Physics MCQ

An optical fiber (or optical fibre) is a flexible, transparent fiber made of glass (silica) or plastic, slightly thicker than a human hair. It functions as a waveguide, or “light pipe”, to transmit light between the two ends of the fiber. Optical fibers typically include a transparent core surrounded by a transparent cladding material with a lower index of refraction. Light is kept in the core by total internal reflection. This causes the fiber to act as a waveguide. Total internal reflection is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary and the incident angle is greater than the critical angle, no light can pass through and all of the light is reflected.

Answer is Option (3) for the Physics MCQ SSC CGL

A mirage is a naturally occurring optical phenomenon in which light rays are bent to produce a displaced image of distant objects or the sky. In contrast to a hallucination, a mirage is a real optical phenomenon which can be captured on camera, since light rays actually are refracted to form the false image at the observer’s location. As light passes from colder air across a sharp boundary to significantly warmer air, the light rays bend away from the direction of the temperature gradient. When light rays pass from hotter to cooler, they bend toward the direction of the gradient. If the air near the ground is warmer than that higher up, the light ray bends in a concave, upward trajectory. Once the rays reach the viewer’s eye, the visual cortex interprets it as if it traces back along a perfectly straight “line of sight”. This line is however at a tangent to the path the ray takes at the point it reaches the eye.

Answer is Option (4) for the SSC CGL Physics MCQ

During daylight, the sky appears to be blue because air scatters blue sunlight more than it scatters red. At night, the sky appears to be a mostly dark surface or region scattered with stars. Except for light that comes directly from the sun, most of the light in the day sky is a result of scattering, which is dominated by a small-particle limit called Rayleigh scattering. The scattering due to molecule sized particles (as in air) is greater in the forward and backward directions than it is in the lateral direction. Scattering is significant for light at all visible wavelengths, but it is stronger at the shorter (bluer) end of the visible spectrum, meaning that that the scattered light is more blue than its source, the sun.

Answer is Option (2) for the Physics MCQ SSC CGL

Flint glass is optical glass that has relatively high refractive index and low Abbe number (high dispersion). A concave lens of flint glass is commonly combined with a convex lens of crown glass to produce an achromatic doublet lens because of their compensating optical properties, which reduces chromatic aberration (colour defects).

Answer is Option (4) for the SSC CGL Physics MCQ

Since the pendulum rate will increase with an increase in gravity, and local gravity varies with latitude and elevation on Earth, pendulum clocks must be readjusted to keep time after a move. For example, a pendulum clock moved from sea level to 4000 feet will lose 16 seconds per day. Even moving a clock to the top of a tall building will cause it to lose measurable time due to lower gravity. Time period of a pendulum taken to the moon will be longer than the period of the same pendulum on earth.

Answer is Option (1) for the Physics MCQ for SSC CGL

The atmosphere is an ocean of air held in place by gravity, extending from the surface to an altitude of hundreds of kilometers, the edge of space. Energy from the sun heating the air and land surface to different degrees, drives atmospheric circulation. Patterns of circulation are also influenced by Earth’s rotation, latitude and the distribution of land, ocean and ice. Surface gravity, the force that holds down an atmosphere, differs significantly among the planets. For example, the large gravitational force of the giant planet Jupiter is able to retain light gases such as hydrogen and helium that escape from lower gravity objects.

Answer is Option (2) for the SSC CGL Physics MCQ

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. In general, it’s main function is to convert kinetic friction into rolling friction. It achieves this by using at least two races to contain the balls and transmit the loads through the balls.

75. ‘Shock-absorbers’ are usually made of steel as it :

(1) is not brittle

(2) has lower elasticity

(3) has higher elasticity

(4) has no ductile property

Answer is Option (3) for the Physics MCQ SSC CGL

A shock absorber is a mechanical device designed to smooth out or damp shock impulse, and dissipate kinetic energy. Steel is an alloy made by combining iron and other elements, the most common of these being carbon. When carbon is used, its content in the steel is between 0.2% and 2.1% by weight, depending on the grade. Varying the amount of alloying elements and the form of their presence in the steel (solute elements, precipitated phase) controls qualities such as the higher elasticity, hardness, ductility, and tensile strength of the resulting steel.

Answer is Option (1) for the SSC CGL Physics MCQ

The speed of sound is the distance travelled during a unit of time by a sound wave propagating through an elastic medium. In dry air at 20 °C (68 °F), the speed of sound is 343.2 metres per second (1,126 ft/s). the speed of sound varies from substance to substance. Sound travels faster in liquids and nonporous solids than it does in air. It travels about 4.3 times as fast in water (1,484 m/s), and nearly 15 times as fast in iron (5,120 m/s), than in air at 20 degrees Celsius. Sound waves in solids are composed of compression waves (just as in gases and liquids), but also exhibit a different type of sound wave called a shear wave, which occurs only in solids.

Answer is Option (4) for the Physics MCQ SSC CGL

In optics, Lambert’s cosine law says that the radiant intensity or luminous intensity observed from an ideal diffusely reflecting surface or ideal diffuse radiator is directly proportional to the cosine of the angle between the observer’s line of sight and the surface normal. The law is also known as the cosine emission law or Lambert’s emission law. A surface which obeys Lambert’s law is said to be Lambertian, and exhibits Lambertian reflectance. Such a surface has the same radiance when viewed from any angle. This means, for example, that to the human eye it has the same apparent brightness (or luminance).

Answer is Option (1) for the SSC CGL Physics MCQ

Superconductors are materials that carry electrical current with little or no resistance when cooled below a certain temperature. While conventional superconductors need to be cooled close to absolute zero (-273.15 °C) before they super conduct, high temperature superconductors do so above the boiling point of liquid nitrogen (-196 °C).

Answer is Option (4) for the Physics MCQ SSC CGL

In digital logic, an inverter or NOT gate is a logic gate which implements logical negation. An inverter circuit outputs a voltage representing the opposite logic-level to its input. Inverters can be constructed using a single NMOS transistor or a single PMOS transistor coupled with a resistor.

Answer is Option (2) for the SSC CGL Physics MCQ

Persistence of vision is the phenomenon of the eye by which an afterimage is thought to persist for approximately one twenty-fifth of a second on the retina. In the early days of cinema, it was scientifically determined that a frame rate of less than 16 frames per second (frame/s) caused the mind to see flashing images. Audiences still interpret motion at rates as low as ten frames per second or slower, but the flicker caused by the shutter of a film projector is distracting below the 16-frame threshold.

Answer is Option (1) for the Physics MCQ SSC CGL

In photography, shutter speed or exposure time is the effective length of time a camera’s shutter is open. The total exposure is proportional to this exposure time, or duration of light reaching the film or image sensor. The correct exposure for a particular object depends on the brightness of the object to be photographed.

Answer is Option (2) for the SSC CGL Physics MCQ

Normal speech is about 60 dB (decibels). A dangerous sound is anything that is 80 dB or higher which can lead to hearing loss. At 70 dB or lower, the risk of harm to healthy ears is negligible. Listening to sound above 80 decibels can cause profound deafness.

Answer is Option (3) for the Physics MCQ SSC CGL

A Newton Disc can be created by painting a disc with the seven different colours. A combination of red, green and blue in the circular disc will yield the same result. This is due to the phenomenon called persistence of vision.

Answer is Option (1) for the SSC CGL Physics MCQ

The dimensions of Force are M (mass), L (length) and T (time). It can also be expressed as

[newton] = [kilogram] [metre] [second] \(\displaystyle ^{{-2}}\).

Answer is Option (4) for the Physics MCQ SSC CGL

The use of a long strand of plastic (or other material such as glass) to pipe light from one end of the medium to the other is the basis for modern day use of optical fibers. Since total internal reflection takes place within the fibers, no incident energy is ever lost due to the transmission of light across the boundary.

Answer is Option (1) for the SSC CGL Physics MCQ

The Farad is the SI derived unit of capacitance. It is named after the English physicist Michael Faraday.

 Answer is Option (3) for the Physics MCQ SSC CGL

Elasticity is the capability of an object to return to its former shape once a load inducing strain is removed. Young Modulus or elastic modulus [tendency to be deformed elastically (i.e., non-permanently) when a force is applied to it]of steel is more than that of rubber.

 Answer is Option (3) for the Physics MCQ SSC CGL

Semiconductors are insulators at low temperatures and reasonably good conductors at higher temperatures. As temperature increases, the semiconductor material becomes a better and better conductor.

Answer is Option (1) for the SSC CGL Physics MCQ

A television channel is a physical or virtual channel over which a television station or television network is distributed. Channel numbers represent actual frequencies used to broadcast the television signal. For example, in North America, “channel 2” refers to the broadcast or cable band of 54 to 60 MHz, with carrier frequencies of 55.25 MHz for NTSC analog video (VSB) and 59.75 MHz for analog audio (FM), or 55.31 MHz for digital ATSC (8VSB).

Answer is Option (2) for the Physics MCQ SSC CGL

Water never has an absolute density because its density varies with temperature. Water has its maximum density of 1g/cm³ at 4 degrees Celsius. When the temperature changes from either greater or less than 4 degrees, the density will become less than 1 g/cm³. Water has the maximum density of 1 g/cm³ only when it is pure water.

Answer is Option (3) for the SSC CGL Physics MCQ

The lower atmosphere is more or less transparent to radio waves. However, the ionosphere reflects back the radio waves. Thus, a signal emitted by an antenna from a certain place can be received at another place on the surface of Earth in the following two ways: ground wave propagation and sky wave propagation.

Answer is Option (4) for the SSC CGL Physics MCQ

A photon is an elementary particle, the quantum of light and all other forms of electromagnetic radiation. The modern photon concept was developed gradually by Albert Einstein.

 Answer is Option (3) for the Physics MCQ SSC CGL

It happens because of viscosity. The viscosity of a fluid is a measure of its resistance to gradual deformation by shear stress or tensile stress. It is due to friction between neighboring parcels of the fluid that are moving at different velocities.

Answer is Option (4) for the Physics MCQ SSC CGL

A White Hole is a hypothetical hole in outer space from which energy, stars, and other celestial matter emerge or explode. It is a theoretical celestial object into which matter is funneled from a black hole.

Answer is Option (1) for the SSC CGL Physics MCQ

Light scattering in colloidal solutions or particles in suspension is known as Tyndall Effect. It is similar to Rayleigh scattering, in that the intensity of the scattered light depends on the fourth power of the frequency, so blue light is scattered much more strongly than red light.

Answer is Option (4) for the Physics MCQ SSC CGL

Reactors are industrial processing tanks for the treatment of wastewater. The tanks have a “flow through” system, with raw wastewater (influent) coming in at one end and treated water (effluent) flowing out the other. While one tank is in settle/ decant mode the other is aerating and filling.

Answer is Option (2) for the SSC CGL Physics MCQ

Electrons carry current in a good conductor of electricity and they are negatively charged. This makes a good electrical conductor negatively charged.

Answer is Option (3) for the Physics MCQ

Bragg Spectrometer is an instrument used to analyze crystal structure by using X-rays. In it, a beam of collimated X-rays strikes the crystal, and a detector measures the angles and intensities of the reflected beam.

Answer is Option (3) for the Physics MCQ SSC CGL

Alpha particles consist of two protons and two neutrons bound together into a particle identical to a helium nucleus, which is generally produced in the process of alpha decay.

Answer is Option (4) for the SSC CGL Physics MCQ

The tesla (symbol T) is the SI derived unit used to measure magnetic fields. Tesla can be measured in different ways; for example, one tesla is equal to one Weber per square meter. The tesla was first defined in 1960 by the General Conference on Weights and Measures (CGPM). It was named in honor of the physicist, electrical engineer, and inventor, Nikola Tesla.

Answer is Option (3) for the SSC CGL Physics MCQ

In circular motion, the magnitude of the velocity of the body is constant but the direction is constantly changing. This means that, even though the speed is not changing, the velocity is changing. This means that body moving in a circular is accelerating. At any instant, the direction of the velocity is a tangent to the circular path. A body moving at constant speed in a circular path experiences an acceleration directed towards the centre of the circular path. This acceleration is called a centripetal acceleration and is provided by a centripetal force. Overall, the displacement, velocity and acceleration are vector quantities. They change; but kinetic energy remains constant because the speed is constant.

Answer is Option (3) for the Physics MCQ SSC CGL

On a chilly day, the room temperature is lower than our body temperature. Since metals have a higher coefficient of thermal conductivity than plastic, they are better conductor of heat than plastic. So, when we touch the metal cap and the plastic body of a pen, heat from our fingers will flow to the metal cap much more quickly than to the plastic body.

Answer is Option (3) for the Physics MCQ SSC CGL

A transformer is an electrical device that transfers energy from one circuit to another by magnetic coupling with no moving parts. It converts high voltage AC into low voltage AC and vice-versa. It is based upon the principle of mutual induction. Transformers alone cannot convert AC to DC or DC to AC; besides, they cannot change the voltage or current of DC.

Answer is Option (3) for the SSC CGL Physics MCQ

Sound “quality” or “timbre” describes those characteristics of sound which allow the ear to distinguish sounds which have the same pitch and loudness. Timbre is mainly determined by the harmonic content of a sound and the dynamic characteristics of the sound such as vibrato and the attack-decay envelope of the sound. Harmonic content is the most important of these.

Answer is Option (4) for the Physics MCQ SSC CGL

When fast moving electrons strike on high atomic weight substance, X – ray is produced. In contrast, Photoelectric effect takes place when radiation of sufficient frequency incident on the metal surface and electrons are emitted. Hence, X – ray is the inverse phenomenon of photoelectric effect.

Answer is Option (4) for the SSC CGL Physics MCQ

A single solar cell can produce only a small amount of electricity. In those cases where more electrical power is needed, a large number of solar cells are joined in series. This group of solar cells is called a ‘solar cell panel’. Thus, a solar cell panel consists of a large number of solar cells joined together in a definite pattern.

Answer is Option (3) for the SSC CGL Physics MCQ

Copper is generally preferred for electrical power transmission instead of iron because of its high electrical conductivity and low resistivity. The conductivity (in s (S/m) at 20 °C) of copper is 5.96×107, while that of iron is 1.00×107. Among metals, silver has the highest electrical conductivity of 6.30×107, but it is not used commonly due to its high cost.

Answer is Option (1) for the Physics MCQ SSC CGL

The Sun is a main-sequence star, and thus generates its energy by nuclear fusion of hydrogen nuclei into helium. In its core, the Sun fuses 620 million metric tons of hydrogen each second. Fusion is a nuclear reaction in which two or more atomic nuclei come very close and then collide at a very high speed and join to form a new nucleus.

Answer is Option (4) for the SSC CGL Physics MCQ

A fuse wire is a safety wire connected in series with the live wire that has high resistivity and low melting point. Fuses are always connected in series with the component(s) to be protected from overcurrent. In case of any large current supply or malfunctioning in the electric connections, it melts and breaks the electric circuit.

Answer is Option (2) for the Physics MCQ SSC CGL

The hydraulic brake is an arrangement of braking mechanism which uses brake fluid, typically containing glycol ethers or diethylene glycol, to transfer pressure from the controlling mechanism to the braking mechanism. It works on the principle of Pascal’s law which states that “pressure at a point in a fluid is equal in all directions in space”. When pressure is applied on a fluid it travels equally in all directions so that uniform braking action is applied on all wheels.