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. Which among the following is measured using a Vernier Caliper?
[A] Dimensions
[B] Time
[C] Sound
[D] Temperature
Show Answer
Correct Answer: A [Dimensions]
Notes:
The Vernier caliper has a main scale and a sliding vernier scale which can measure nearest to 0.02 mm. It can be used to measure internal and the external dimensions of an object by using the smaller jaws at the top and the main jaws respectively. By using stems depth can be measured.
2. 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
Show Answer
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.
3. “Fermi” is a unit of which among the following?
[A] Mass
[B] Length
[C] Velocity
[D] Frequency
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Correct Answer: B [Length]
Notes:
“Fermi” is the unit of length. The femtometre is an SI unit of length equal to 10⁻¹⁵ metres, which means a quadrillionth of one.
4. Which of the following lie in the Tetra hertz frequency?
[A] Visible Light and Infra Red
[B] Infra Red and Microwaves
[C] Microwaves and Radio Waves
[D] Visible Light and Ultraviolet light
Show Answer
Correct Answer: B [ Infra Red and Microwaves]
Notes:
The range of the tera hertz radiation frequency is from roughly 0.1 THz to 10 THz. It is higher than the frequency of radio waves and microwaves, but lower than the frequency of infrared light.
5. If a moving body turns its speed to 1.5 times, its kinetic energy __:
[A] will become 1.5 times
[B] will become 3 times
[C] will become 2.25 times
[D] will become 6 times
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Correct Answer: C [ will become 2.25 times]
Notes:
Kinetic Energy is a product of half the Mass times Velocity Squared. When the velocity is doubled, the Kinetic energy would go up four times. If velocity is tripled, kinetic energy would go up nine times. If velocity is increased by 1.5 times the Kinetic energy would go up by 1.5×1.5=2.25 times.
6. The acceleration at a given instant of time is called as:
[A] Average acceleration
[B] Instantaneous acceleration
[C] Variable acceleration
[D] Zero acceleration
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Correct Answer: B [Instantaneous acceleration]
Notes:
The acceleration of an object at a given instant of time is called Instantaneous acceleration. When an object moves with variable acceleration, then it possesses different acceleration at different point of time.
7. What is the relationship between the angle of friction and the angle of repose?
[A] Equal to the angle of repose
[B] Twice the angle of repose
[C] Greater than the angle of repose
[D] Lesser than the angle of repose
Show Answer
Correct Answer: A [Equal to the angle of repose]
Notes:
The angle of friction is indeed equal to the angle of repose. The angle of repose is, to put it simply, the steepest angle at which a sloping surface formed of a particular loose material is stable. It signifies the maximum angle at which an object can rest on an inclined plane without sliding.
8. 1 kilogram force produces how much acceleration in a body of mass 1 kg?
[A] 1 ms-2
[B] 0
[C] 9.8 ms-2
[D] -1 ms-2
Show Answer
Correct Answer: C [9.8 ms-2]
Notes:
1 Kilogram force or 1 Kilogram weight is that much force which produces an acceleration of 9.8 ms-2 in a body of mass 1 kg. Also, 1 kg wt. or 1 kg f = 9.8 N
9. Which of the following is/are correct about Kinetic energy?
[A] Kinetic energy can be positive or negative
[B] Kinetic energy is independent of frame of reference
[C] Both a and b
[D] None of the above
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Correct Answer: D [None of the above]
Notes:
Kinetic energy of a body is half the product of mass of the body and square of the velocity of the body. K.E = 1/2(mv2) Kinetic energy depends on the frame of reference. Kinetic energy of a body is always positive.
10. Which of the following statements is correct?
[A] The acceleration due to gravity is same at the equator and the poles
[B] The acceleration due to gravity is maximum at the poles
[C] The acceleration due to gravity is least at the poles
[D] None of the above
Show Answer
Correct Answer: B [The acceleration due to gravity is maximum at the poles]
Notes:
The acceleration due to gravity is maximum at the poles and is least at the equator. The value of acceleration due to gravity increases as we go from the equator to the pole.
