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. “Fermi” is a unit of which among the following?
[A] Mass
[B] Length
[C] Velocity
[D] Frequency
Show Answer
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.
2. If earth stops rotating, the impact on weight of a body will be minimum on which among the following places?
[A] Equator
[B] North Pole
[C] Tropic of Cancer
[D] Tropic of Capricorn
Show Answer
Correct Answer: B [North Pole]
Notes:
The question is related to the centrifugal forces, which represent the effects of inertia that arise in connection with rotation and which are experienced as an outward force away from the center of rotation. The impact of this force is maximum at Equator and minimum at Pole.
3. Electron microscope works on which of the following principles?
[A] Optical interference
[B] Wave Nature of electrons
[C] Motion of charged particle in electromagnetic fields
[D] Faraday’s law of Electromagnetic induction
Show Answer
Correct Answer: B [Wave Nature of electrons]
Notes:
Electron microscope works on the principle of Wave Nature of electrons. Electron microscopes use an electron beam instead of visible light and an electron detector instead of our eyes. An electron beam allows us to see at very small scales because electrons can also behave as light due to its wave nature.
4. Curie the a unit of which of the following?
[A] Luminescence
[B] Radioactivity
[C] Pressure
[D] Mass
Show Answer
Correct Answer: B [ Radioactivity ]
Notes:
The curie is a unit of ionizing radiation (radioactivity). It is symbolized with Ci . 1 curie = 3.7 x 10 10 disintegrations or nuclear transformations per second. This is approximately the amount of radioactivity emitted by one gram (1 g) of radium-226. The unit is named after Pierre Curie, a French physicist.
5. Which of these is/are examples of conservation of linear momentum?
[A] Explosion of bomb
[B] Recoiling of a gun
[C] Fight of rockets and jet planes
[D] All of the above
Show Answer
Correct Answer: D [All of the above]
Notes:Some examples of conservation of linear momentum:
- Recoiling of a gun
- Explosion of bomb
- Fight of rockets and jet planes
- A man jumping out of a boat to the shore
- A person on a frictionless surface
6. The energy by virtue of its position is known as:
[A] Kinetic energy
[B] Potential energy
[C] Internal energy
[D] Heat energy
Show Answer
Correct Answer: B [Potential energy]
Notes:
The energy by virtue of its position is known as Potential energy. The energy by virtue of its motion is known as Kinetic energy.
7. 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.
8. What will be the effect on the value of acceleration due to gravity at the poles if the rate of rotation of earth increases?
[A] No effect
[B] it will increase
[C] it will decrease
[D] it will become zero
Show Answer
Correct Answer: A [No effect]
Notes:
If the rate of rotation of earth increases then the value of acceleration due to gravity decreases at all the places on the surface of earth except at poles.
9. The ratio of the magnitude of the external force applied on a body to the magnitude of acceleration produced in its motion is known as:
[A] Inertial Mass
[B] Angular Momentum
[C] Gravitational Potential
[D] Gravitational Constant
Show Answer
Correct Answer: A [Inertial Mass]
Notes:
The inertial mass of a body may be measured as the ratio of the magnitude of the external force applied on it to the magnitude of acceleration produced in its motion. It is the measure of ability of the body to oppose the production of acceleration in its motion by an external force.
10. What is the orbital velocity of geo stationary satellite?
[A] 4.15 km/s
[B] 2.78 km/s
[C] 3.08 km/s
[D] 6.66 km/s
Show Answer
Correct Answer: C [3.08 km/s]
Notes:
Orbital velocity of geo stationary satellite can be calculated as (GM/r)1/2. The orbital velocity of geo stationary satellite is 3.08 km/s.
