Physics MCQs
Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, NDA, CDS and all one day examinations of India.
1. Speed of sound is maximum in which among the following?
[A] Solids
[B] liquids
[C] Gases
[D] Vaccum
Show Answer
Correct Answer: A [Solids]
Notes:
The speed of sound decreases when we go from solid to gaseous state.
2. The ideal fluid which is a hypothetical fluid should contain _______?
[A] Zero Viscosity Only
[B] Zero Compressibility Only
[C] Zero Viscosity & Zero Compressibility
[D] None of the above
Show Answer
Correct Answer: C [Zero Viscosity & Zero Compressibility]
Notes:
An ideal fluid hypothetical fluid should contain Zero Viscosity & Zero Compressibility. Almost all fluids will not have zero viscosity and zero compressibility.
3. The speed of Sound is maximum in which of the following ?
[A] Air at zero degree C
[B] Air at 100 degree C
[C] Water
[D] Same in all
Show Answer
Correct Answer: C [Water]
Notes:The speed of sound in a medium is determined by the properties of that medium, primarily its density and elasticity. The speed of sound is fastest in solids, followed by liquids, and then gases. Let’s analyze the given options:
[A] Air at zero degrees Celsius: The speed of sound in air increases with temperature. At lower temperatures, the molecules in the air have less kinetic energy, which results in a slower speed of sound. So, the speed of sound in air at 0°C is slower compared to higher temperatures.
[B] Air at 100 degrees Celsius: As mentioned earlier, the speed of sound in air increases with temperature. So, the speed of sound in air at 100°C would be faster than at 0°C but still slower than in a solid or liquid.
[C] Water: The speed of sound in water is significantly faster than in air. Water is denser and more elastic than air, which allows sound waves to travel through it more quickly.
[D] same in all: This statement is not correct. The speed of sound varies depending on the medium. It is not constant and is definitely not maximum everywhere.
So, among the given options, the maximum speed of sound would be in “Water” (Option C).
4. While passing over an obstacle a light ray slightly bends round the corner. The phenomenon is known as__:
[A] Scattering
[B] Polarisation
[C] Diffraction
[D] Refraction
Show Answer
Correct Answer: C [ Diffraction]
Notes:
The phenomenon of light rays bending around the corners of obstacles is called diffraction. Diffraction refers to various phenomena that occur when a wave encounters an obstacle or a slit.
5. What is the angular acceleration of a body moving with constant angular velocity?
[A] equal to the angular velocity
[B] 1
[C] 0
[D] Can’t be determined
Show Answer
Correct Answer: C [0]
Notes:
The angular acceleration of a body moving with constant angular velocity is 0. Angular acceleration of an object in circular motion is defined as the time rate of change of its angular velocity.
6. Which of the following is/are independent of mass during the projectile motion?
[A] Time of Flight
[B] Horizontal Range
[C] Maximum Height
[D] All of the above
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Correct Answer: D [All of the above]
Notes:
The Time of Flight, Horizontal Range and the Maximum Height of an object are independent of mass of the object during the projectile motion.
7. The work done in moving a body over a smooth inclined plane does not depend on which of the following?
[A] mass of the body
[B] height of the inclined plane
[C] slope of the inclined plane
[D] All of the above
Show Answer
Correct Answer: C [slope of the inclined plane]
Notes:
The work done in moving a body over a smooth inclined plane does not depend on the slope of the inclined plane. W = mgh in case of smooth inclined plane, where m = mass of the body, g = acceleration due to gravity and h = height of the inclined plane.
8. By how much the orbital velocity of Moon has to increase for it to cease to remain the earth’s satellite?
[A] 2 times
[B] 3 times
[C] √2 times
[D] √3 times
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Correct Answer: C [√2 times]
Notes:
If the speed of a satellite orbiting close to the earth is made √2 times (or increased by 41%) then it will escape from the gravitational field. Moon is a natural satellite of earth.
9. The distance of Neptune and Saturn from sun are nearly 1013 and 1012 meters respectively. Assuming that they move in circular orbits, what will be the ratio of their periodic times?
[A] 40
[B] 10√10
[C] 20√20
[D] 30√30
Show Answer
Correct Answer: B [10√10]
Notes:
By using Kepler’s third law, Tneptune/Tsaturn = (Rneptune/Rsaturn)3/2
10. What is the property of matter by which a body tends to regain its original configuration after the removal of deforming force known as?
[A] Plasticity
[B] Ductility
[C] Elasticity
[D] Malleability
Show Answer
Correct Answer: C [Elasticity]
Notes:
The property of matter because of which a body tends to regain its original shape and size after the deforming force is removed is called its elasticity. Plasticity: It is that property of matter by virtue of which it does not regain its original shape and size after the removal of deforming force.
