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 of the following term denotes the internal reaction force per unit area developed as a result of applied external force ?
[A] Stress
[B] Friction
[C] Moment of Inertia
[D] tension
Show Answer
Correct Answer: A [Stress]
Notes:
Stress is the force acting per unit area. It is the internal force reaction per unit area developed as a result of external force.
2. On which of the following the jet Engine works?
[A] Conservation of energy
[B] Conservation of Linear Momentum
[C] Conservation of Mass
[D] Conservation of Angular momentum
Show Answer
Correct Answer: B [Conservation of Linear Momentum]
Notes:Conservation of Linear Momentum law says that if no external force acts on a system, then its total linear momentum remains conserved. In equation form, Momentum=mass*velocity. To increase the momentum of an object, we need to either increase its mass or velocity or both.
- Rockets work on law of conservation of momentum. As momentum in one direction is given to the rocket’s exhaust gases, momentum in the other direction is given to the rocket itself.
3. Which among the following strictly works on the principle of dipole movement of the water molecules?
[A] Refrigerator
[B] Microwave Oven
[C] Air Conditioner
[D] Electric Geyser
Show Answer
Correct Answer: B [Microwave Oven]
Notes:
Microwave Oven strictly works on the principle of dipole movement of water molecule. A microwave oven is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range.
4. The term “Isopycnic” is most closely defined by which among the following?
[A] Two places with same atmospheric pressure
[B] Two liquids with same viscosity
[C] Two liquids with same density
[D] Two places with same temperature
Show Answer
Correct Answer: C [Two liquids with same density]
Notes:
The term “Isopycnic” refers to two substances having the same density. It is derived from the Greek words “iso,” meaning equal, and “pycnos,” meaning dense. In scientific contexts, isopycnic conditions are often used in centrifugation techniques to separate particles based on their density, such as in the purification of DNA or proteins.
5. If the time taken in an echo is 5 seconds, which among the following will be the approximate distance of the object from source of sound? (assume normal room temperature at 20°C)
[A] 1715 meters
[B] 1256 meters
[C] 857 meters
[D] 554 meters
Show Answer
Correct Answer: C [ 857 meters]
Notes:To calculate the distance of the object from the source of sound based on the time taken for the echo, we can use the formula for distance traveled by sound:
Distance = (Speed of Sound × Time) / 2
The speed of sound in air at normal room temperature (20°C) is approximately 343 meters per second (m/s).
Given that the time taken in the echo is 5 seconds, we can plug the values into the formula:
Distance = (343 m/s × 5 s) / 2 Distance = 1715 meters / 2 Distance ≈ 857.5 meters
So, the approximate distance of the object from the source of sound is approximately 857.5 meters.
6. Large Underground Xenon experiment (LUX) is being carried out in which country?
[A] U.S.A
[B] Russia
[C] China
[D] Japan
Show Answer
Correct Answer: A [ U.S.A]
Notes:
Large Underground Xenon experiment (LUX) is located 1,510 m underground at the Sanford Underground Laboratory in Lead city, South Dakota, United States.
7. Which of these branches of Physics deal with heat and temperature and their relation to energy and work?
[A] Geophysics
[B] Mechanics
[C] Atomic Physics
[D] Thermodynamics
Show Answer
Correct Answer: D [Thermodynamics]
Notes:
Thermodynamics is that branch of physics which deals with heat and temperature and their relation to energy (such as mechanical, electrical, or chemical energy) and work. The behaviour of these quantities is governed by the four laws of thermodynamics
8. 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
Show Answer
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.
9. What kind of energy is stored in the spring of a watch?
[A] Kinetic
[B] Potential
[C] Heat
[D] Chemical
Show Answer
Correct Answer: B [Potential]
Notes:
Potential energy is stored in the spring of a watch. Potential energy is the energy by virtue of an object’s position relative to other objects. It is often associated with restoring forces such as a spring or the force of gravity.
10. The Universal Gravitational Constant for two bodies is dependent on which of the following?
[A] Nature of the bodies
[B] Size of the bodies
[C] Nature of medium between the bodies
[D] None of the above
Show Answer
Correct Answer: D [None of the above]
Notes:
The value of Universal Gravitational Constant is same throughout the universe. It is independent of nature of the bodies, size of the bodies and nature of medium between the bodies.
