MOST Important CDS GK Question of Physics 2023

In this blog you will get MOST Important and previously asked CDS general knowledge question of Physics with answers which you must practice for your common defence exam . Alot of candidate looks for CDS different section question to practice and improve their preparation level . So here we have provided top 50 mostly asked physics gk questions in general knowledge paper of CDS exam .

Every year CDS exam is conducted by UPSC twice a year which is called CDS-1 & CDS-2 . In CDS exam there is a section of general knowledge which consist question of physics of gk type which candidate must practice .Below are some of the most important physics general knowledge questions with answer which can be useful for various competitive exam like CDS , NDA , AFCAT etc .

Physics General Knowledge Questions:

NOTE: The answer of the below questions are given at the ending .

1. Which one of the following Indian scientists was elected as a fellow of the Royal Society of London for his contribution in the field of Plant Physiology and Physics?
(a) Jagdish Chandra Bose
(b) Ashutosh Mukherjee
(c) Prafulla Chandra Ray
(d) P C Mahalanobis
2. Assertion (A): Steam is more harmful for human body than the boiling water in case of burn.
Reason (R): Boiling water contains more heat than steam.

(a) Both A and R are true, and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
3. Why is it difficult to see through fog?
(a) Rays of light suffer total internal reflection from the fog droplets
(b) Rays of light are scattered by the fog droplets
(c) Fog droplets absorb light
(d) The refractive index of fog is extremely high
4. The density of water varies with temperature which helps the aquatic animals to live in cold water. At what temperature is the density of water maximum?
(a) 1°C
(b) 2°C
(c) 3°C
(d) 4°C
5. Who gave the first evidence of the big-bang theory?
(a) Edwin Hubble
(b) Albert Einstein
(c) S Chandrasekhar
(d) Stephen Hawking
6. A ray of light is incident on a plane mirror at an angle 30° with the normal at the point of incidence. The ray will be deviated from its incidence direction by what angle?
(a) 30°
(b) 60°
(c) 120°
(d) None of these
1. What would be the best choice for window material to keep the outside heat away?
(a) Single-pane glass
(b) Double-pane glass without a gap in between
(c) Double-pane glass with water filled in between
(d) Double-pane glass with air in between
2. Bar is a unit of which one of the following?
(a) Force
(b) Energy
(c) Pressure
(d) Frequency
3. On which one of the following conservative laws, does a rocket work?
(a) Mass
(b) Energy
(c) Linear momentum
(d) Angular momentum
4. Assertion (A): In a pressure cooker food is cooked above boiling point.
Reason (R): Boiling point of water increases as the pressure increases.

(a) Both A and R are true and R is the correct explanation of A
(b) Both A and R are true, but R is not the correct explanation of A
(c) A is true, but R is false
(d) A is false, but R is true
5. The phenomenon of mirage occurs due to which one of the following?
(a) Polarization of light
(b) Dispersion of light
(c) Diffraction of light
(d) Total internal reflection of light
6. Which one of the following common devices works on the basis of the principle of mutual induction?
(a) Tube light
(b) Transformer
(c) Photodiode
(d) LED
7. Television signal cannot be received generally beyond a particular distance due to
(a) Curvature of the Earth
(b) Weakness of antenna
(c) Weakness of signal
(d) Absorption of signal in air
1. If a small raindrop falls through air
(a) Its velocity goes on increasing
(b) Its velocity goes on decreasing
(c) Its velocity goes on increasing for some time and then becomes constant
(d) It falls with constant speed for some time and then its velocity increases
2. Consider the following statements X-rays
1. Can pass through aluminum.
2. Can be deflected by magnetic field.
3. Move with a velocity less than the velocity of ultraviolet ray in vacuum.
(a) 1, 2 and 3
(b) Only 1
(c) 2 and 3
(d) 1 and 2
3. Which one of the following is the permissible level of noise in a silent zone at day time?
(a) 50 dB
(b) 60 dB
(c) 65 dB
(d) 75 dB
4. By which one of the following, an old written material which cannot be read easily, can be read
(a) γ-rays
(b) X-rays
(c) IR-rays
5. Earthquake (shock) waves are
(a) Infrasonic waves
(b) Ultrasonic waves
(c) Seismic
(d) Infrared waves
6. Laser is a device to produce
(a) A beam of white light
(b) Coherent light
(c) Microwaves
(d) X-rays
7. A perfect black body has the unique characteristic feature as
(a) A good absorber only
(c) A good absorber and a good radiator
(d) Neither a radiator nor an absorber
1. Fat can be separated from milk in a cream separation because of
(a) Cohesive force
(b) Gravitational force
(c) Centrifugal force
(d) Centripetal force
2. Which one of the following is not result of surface tension?
(a) Vapour formation above the liquid surface
(b) Convex shape of liquid meniscus
(c) Liquid rising in a capillary
(d) Spherical shape of mercury fallen on the floor
3. Hair of a shaving brush clings together when the brush is removed from water due to
(a) Viscosity
(b) Surface tension
(c) Friction
(d) Elasticity
4. Consider the following statements
1. Clear sky appears blue due to poor scattering of blue wavelength of visible light.
2. Red part of light shows more scattering than blue light in the atmosphere.
3. In the absence of atmosphere, there would be no scattering of light and sky will look
black.
Which of the statements given above is/are correct?

(a) Only 1
(b) 1 and 2
(c) Only 3
(d) All of these
5. The most familiar form of radiant energy in sunlight that causes tanning and sun burning of human skin, is called
6. A boy throws four stones of same shape, size and weight with equal speed at different initial angles with the horizontal line. If the angles are 15°, 30°, 45° and 60°, at which angle the stone will cover the maximum horizontally?
(a) 15°
(b) 45°
(c) 30°
(d) 60°
1. Which one of the following statement is true?
(a) Temperatures differing 25° on the Fahrenheit (F) scale must differ by 45° on the Celsius (C) scale
(b) 0°F corresponds to – 32°C
(c) Temperatures which differ by 10° on the Celsius scale must differ by 18° on the Fahrenheit scale
(d) Water at 90°C is warmer than water at 202°F
2. A diffraction pattern is obtained using a beam of red light. Which one among the following will be the outcome, if the red light is replaced by blue light?
(a) Bands disappear
(b) Diffraction pattern becomes broader and further apart
(c) Diffraction pattern becomes narrower and crowded together
(d) No change
3. Raw mangoes shrivel when pickled in brine. The phenomenon is associated with
(a) Reverse osmosis
(b) Osmosis
(c) Increase of surface tension of fluid
(d) Decrease of surface tension of fluid
4. The apparent weight of a steel sphere immersed in various liquids is measured using a spring balance. The greatest reading is obtained for the liquid
(a) Having the smallest density
(b) Having the largest density
(c) In which the sphere was submerged deepest
(d) Having the greatest volume
5. If an object having mass of 1 kg is subjected to a force of 1 N it moves with
(a) A speed of 1 m/s
(b) A speed of 1 km/s
(c) An acceleration of 1 𝑚 per sec square
(d) An acceleration of 10 𝑚 𝑚 per sec square
6. An athlete diving off a high springboard can perform a variety of exercises in the air before entering the water below. Which one of the following parameters will remain constant during
the fall?

(a) The athlete’s linear momentum
(b) The athlete’s moment of inertia
(c) The athlete’s kinetic energy
(d) The athlete’s angular momentum
1. The pressure exerted on the ground by a man is greatest
(a) When the lies down in the ground
(b) When the stands on the toes of one foot
(c) When the stands with both foot flat on the ground
(d) All of the above yield the same pressure
2. A passenger in a moving train tosses a five rupee coin. If the coin falls behind him, then the train must be moving with a uniform
(a) Acceleration
(b) Deceleration
(c) Speed
(d) Velocity
3. As the sunlight passes through the atmosphere, the rays are scattered by tiny particles of dust, pollen, soot and other minute particulate matters present there. However, when we look up, the sky appears blue during mid-day because
(a) Blue light is absorbed most
(b) Blue light is scattered most
(c) Blue light is reflected most
(d) Ultraviolet and yellow component of sunlight combine
4. The force acting on a particle executing simple harmonic motion is
(a) Directly proportional to the displacement and is directed away from the mean position
(b) Inversely proportional to the displacement and is directed towards the mean position
(c) Directly proportional to the displacement and is directed towards the mean position
(d) Inversely proportional to the displacement and is directed away from the mean position
5. Which one of the following statements is correct?
(a) The angle of contact of water with glass is acute while that of mercury with glass is obtuse
(b) The angle of contact of water with glass is obtuse, while that of mercury with glass is acute
(c) Both the angle of contact of water with glass and that of mercury with glass are acute
(d) None of the above
6. Why are inner lining of hot water geysers made up of copper?
(a) Copper has low heat capacity
(b) Copper has high electrical conductivity
(c) Copper is good conductor of both heat and electricity
(d) Copper does not react with steam
7. Half portion of a rectangular piece of ice is wrapped with a white piece of cloth while the other half with a black one. In this context, which one among the following statements is correct?
(a) Ice melts more easily under black wrap
(b) Ice melts more easily under white wrap
(c) No ice melts at all under the black wrap
(d) No ice melts at all under the white wrap
1. In scuba-diving, while ascending towards the water surface, there is a danger of bursting the lungs. It is because of
(a) Archimedes’ principle
(b) Boyle’s law
(c) Gay-Lussac’s law of combining volumes
(d) Graham’s law of diffusion
2. The blackboard seems black because it
(a) Reflects every colour
(b) Does not reflect any colour
(c) Reflects black colour
(d) Absorbs black colour
3. Mr X was advised by an architect to make outer walls of his house with hollow bricks. The correct reason is that such walls
(a) Make the building stronger
(b) Help keeping inside cooler in summer and warmer in winter
(c) Prevent seepage of moisture from outside
(d) Protect the building from lightning
4. If a ship moves from freshwater into seawater, it will
(a) Sink completely
(b) Sink a little bit
(c) Rise a little higher
(d) Remain unaffected
5. Viewfinders, used in automobiles to locate the position of the vehicles behind, are made of
(a) Plane mirror
(b) Concave mirror
(c) Convex mirror
(d) Parabolic mirror
6. The cat can survive fall from a height much more than human or any other animal. It is because the cat
(a) Can immediately adjust itself to land on all four paws and bend the legs to absorb the impact of falling
(b) Has elastic bones
(c) Has thick and elastic skin
(d) Also gets injury equally with other animals, but has tremendous endurance, resistance and
speedy recovery
7. Fire fly gives us cold light by virtue of the phenomenon of
(a) Chemiluminescence
(b) Phosphorescence
(c) Fluorescence
(d) Effervescence
1. Transformer is a kind of appliance that can
1. Increase power
2. Increase voltage
3. Decrease voltage
4. Measure current and voltage
Select the correct answer using the codes given below

(a) Only 4
(b) 1 and 4
(c) 2 and 3
(d) 2, 3 and 4
2. A body has a mass of 6 kg on the Earth; when measured on the Moon, its mass would be
(a) Nearly 1 kg
(b) Less than 1 kg
(c) Less than 6 kg
(d) 6 kg
3. When a ball drops onto the floor it bounces. Why does it bounce?
(a) Newton’s third law implies that for every action (drop) there is a reaction (bounce)
(b) The floor exerts a force on the ball during the impact
(c) The floor is perfectly rigid
(d) The floor heats up on impact
4. If the door of a running refrigerator in a closed room is kept open, what will be the net effect on the room?
(a) It will heat the room
(b) It will cool the room
(c) It will make no difference on the average
(d) It will make the temperature go up and down

Conclusion:

To succeed in any competitive exam you need to practice very hard along with building your concept. Practicing general knowledge physics question for CDS exam will help you to understand your level of preparation of the exam . By practicing you will get aware about your weak points which you can improve before the actual exam . Ndabooks is committed to help various aspirant who wanted to prepare for defence exam like NDA , CDS , AFCAT and many other .

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