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. Any moving object on earth finally comes to rest due to which among the following?
[A] Gravity
[B] Friction
[C] Inertia
[D] Motion
Show Answer
Correct Answer: B [Friction]
Notes:
Friction is the main reason for any object to come to rest. It is the main reason for the stability of the objects on earth.
2. Knot is a unit of _________?
[A] Speed
[B] Distance
[C] Deapth
[D] Accelration
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Correct Answer: A [Speed]
Notes:
Knot is a unit of speed equal to one nautical mile per hour. 1 knot is equivalent to 1.852 km/h. “kn” is the ISO standard symbol of knot. It is used in the field of meteorology, maritime and air navigation.
3. Which of the following waves can be used to measure the speed of a approaching car?
[A] Light waves
[B] Micro waves
[C] Radio waves
[D] Sound waves
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Correct Answer: C [Radio waves]
Notes:
Radio waves are a type of electromagnetic radiation with wavelengths in the electromagnetic spectrum longer than infrared light. Radio waves have frequencies as high as 300 gigahertz to as low as 30 hertz. It is used to measure the speed of an approaching car.
4. “Svedberg Unit” is a measure of?
[A] Concentration
[B] Size
[C] Density
[D] Time
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Correct Answer: D [Time]
Notes:
A Svedberg unit (S/ Sv) is utilized to denote sedimentation coefficients, providing specific measurement of a particle based on its sedimentation rate under acceleration. Essentially, it computes how quickly a particle settles to the bottom of a solution. In terms of the time dimension, a Svedberg unit amounts to exactly 10−13 seconds, indicating that it is essentially a measure of time.
5. 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
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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.
6. 1 nautical mile is equivalent to which of the following?
[A] 1.44 x 1000 m
[B] 1.852 x 100 m
[C] 1.852 x 1000 m
[D] 1.44 x 100 m
Show Answer
Correct Answer: C [ 1.852 x 1000 m ]
Notes:nautical mile is a unit of length. 1 nautical mile is equal to 1.852 x 1000 m Other important units of length are:
- 1 mile = 1.609 x 1000 m
- 1 light year = 9.46 x 1015 m
- 1 AU = 1.5 x 1011m
- 1 Par sec = 3.1 x 1016m
7. The force acting on a body for a short time are called as:
[A] Average force
[B] Momentum
[C] Impulse
[D] Tension
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Correct Answer: C [Impulse]
Notes:
The force acting on a body for a short time are called as Impulse. Example: hitting a ball with a bat. Impulse = average force x time It is a measure of total effect of the force. Its unit is Ns
8. What is the coefficient of restitution for a perfectly elastic collision?
[A] 0
[B] 1
[C] -1
[D] 100
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Correct Answer: B [1]
Notes:
For a perfectly elastic collision, the coefficient of restitution is equal to 1 as the velocity of separation after collision is equal to the velocity of approach before collision. For a perfectly inelastic collision, the coefficient of restitution is equal to 0 as the velocity of separation after collision is equal to 0. The coefficient of restitution or coefficient of resilience is the ratio of relative velocity of separation after collision and the velocity of approach before collision.
9. What is the ratio of change in configuration to the original configuration called as?
[A] Strain
[B] Stress
[C] Elasticity
[D] Rebound
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Correct Answer: A [Strain]
Notes:
The ratio of change in configuration to the original configuration is called strain. Strain are of three types : 1. Linear 2. Volumetric 3. Shearing
10. What is the internal restoring force acting per unit area of cross section of the deformed body called?
[A] Strain
[B] Stress
[C] Pressure
[D] Surface Tension
Show Answer
Correct Answer: B [Stress]
Notes:
Stress is the internal restoring force acting per unit area of cross section of the deformed body. Stress is given by Force/Area.
