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. A pendulum is taken to Moon, what will happen to its time period?
[A] Increases
[B] Decreases
[C] Remains constant
[D] Either increase or decrease
Show Answer
Correct Answer: A [Increases]
Notes:
When the simple pendulum is taken to the moon, value of gravitational constant g will decrease and thus, its time period will increase.
2. Which among the following principle is used by Bats?
[A] RADAR (Radio Detective & Ranging
[B] SONAR (Sound Navigation & Ranging
[C] law of reflection
[D] law of diffraction
Show Answer
Correct Answer: B [SONAR (Sound Navigation & Ranging]
Notes:
Bats use SONAR (Sound Navigation & Ranging).Sonar is a technique that uses sound propagation to navigate, communicate with or detect objects on or under the surface of the water, such as other vessels.
3. 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.
4. Which among the following is the correct sequence of the terms used for various phases of the rocky object from space entering earth’s atmosphere and reaching on earth?
[A] Meteoroid – Meteor – Meteorite
[B] Meteorite – Meteoroid – Meteor
[C] Meteor – Meteorite – Meteoroid
[D] Meteoroid – Meteorite – Meteor
Show Answer
Correct Answer: A [ Meteoroid – Meteor – Meteorite]
Notes:
A meteoroid is a small rocky or metallic body travelling through space. When such an object enters the Earth’s atmosphere, it heats up from atmospheric friction and produces a streak of light, both from the glowing object and the trail of glowing particles that it leaves in its wake. This phenomenon is called a meteor, or colloquially a “shooting star” or “falling star”. If a meteoroid, comet or asteroid or a piece thereof withstands ablation from its atmospheric entry and impacts with the ground, then it is called a meteorite. (Wikipedia)
5. When you throw a ball with an angle to the horizontal (projectile); the ball has __:
[A] Uniform velocity in horizontal direction but uniform acceleration in vertical direction
[B] Uniform acceleration in horizontal direction but uniform velocity in vertical direction
[C] Uniform acceleration in both horizontal and vertical directions
[D] Uniform velocity in both horizontal and vertical directions
Show Answer
Correct Answer: A [ Uniform velocity in horizontal direction but uniform acceleration in vertical direction]
Notes:
The motion of a projectile is two dimensional motion consisting of (i) horizontal motion and (ii) vertical motion. Hence, at any instant, the velocity of a projectile has two components (i) horizontal component and (ii) vertical component. The horizontal component remains unchanged throughout the flight as there is no acceleration in horizontal direction. The vertical component is continuously affected by the force of gravity. Thus, the horizontal motion is uniform motion but the vertical motion is uniformly accelerated motion.)
6. An Electric generator is based on which of the following scientific principles?
[A] Faraday’s law of Electromagnetic Induction
[B] Super Conductivity
[C] Laws of Thermodynamics
[D] Newton’s Law of Motion
Show Answer
Correct Answer: A [Faraday’s law of Electromagnetic Induction]
Notes:
An Electric generator works on the principle of Faraday’s law of Electromagnetic Induction. An electric generator uses mechanical energy to generate electricity applying Faraday’s law of induction. It spins a coil at a constant rate in a magnetic field to induce an oscillating emf.
7. 1 femto metre is equal to how many metres?
[A] 10-12
[B] 10-14
[C] 10-15
[D] 1-24
Show Answer
Correct Answer: C [ 10-15 ]
Notes:1 femto metre is equal to 10
-15 metre. Some other metric prefixes are:
- nano = 10-9
- pico = 10-12
- atto = 10-18
- tera = 1012
- peta = 10-15
- exa = 10-18
8. What is the apparent weight of the person when the elevator is accelerating downwards?
[A] equal to the actual weight
[B] greater than the actual weight
[C] less than the actual weight
[D] 0
Show Answer
Correct Answer: C [less than the actual weight]
Notes:
The apparent weight of the person becomes less than the actual weight when the elevator is accelerating downwards. The apparent weight of the person becomes more than the actual weight when the elevator is accelerating upwards.
9. Which of the following is NOT an example of conservation of mechanical energy?
[A] Vibrations of a simple pendulum
[B] Motion of a small spherical ball over a watch glass
[C] Vibrations of an elastic spring
[D] None of the above
Show Answer
Correct Answer: D [None of the above]
Notes:Some examples of conservation of mechanical energy:
- Vibrations of a simple pendulum
- Motion of a small spherical ball over a watch glass
- Vibrations of an elastic spring
10. 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.
