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 sentence is correct reason behind the blue color of ocean water?
[A] Water molecules absorb all other colors except blue
[B] Impurities in Sea water reflect the blue light
[C] Water molecules scatter the blue light
[D] None of the above
Show Answer
Correct Answer: C [Water molecules scatter the blue light]
Notes:
Water molecules scatter the blue light by absorbing the light waves and then rapidly re-emitting the light waves in different directions. That is why there are mostly blue wavelengths that are reflected back to our eyes.
2. Which among the following is measured by an Odometer?
[A] Pressure
[B] Height
[C] Distance
[D] Velocity
Show Answer
Correct Answer: C [Distance]
Notes:
An odometer is an instrument used for measuring the distance. It measures distance traveled by a vehicle such as a bicycle or car. The device may be electronic, mechanical, or a combination of the two.
3. What is the S.I unit of Coefficient of Mutual inductance?
[A] weber
[B] candela
[C] henry
[D] lambert
Show Answer
Correct Answer: C [ henry ]
Notes:
The unit of Coefficient of Mutual inductance is henry lambert is the S.I unit of Luminance weber is the S.I unit of Magnetic Flux candela is the S.I unit of Luminous Intensity
4. Which of the these physical quantities is a vector quantity?
[A] Temperature
[B] Speed
[C] Gravitational Intensity
[D] Work
Show Answer
Correct Answer: C [Gravitational Intensity]
Notes:
The physical quantities which have both magnitude and direction are called as Vector quantities. Some examples of Vector quantities: Acceleration, Velocity, Torque, Displacement, Gravitational Intensity, Force.
5. What is the relationship between Kinetic and limiting friction?
[A] Kinetic friction is slightly greater than limiting friction
[B] Kinetic friction is slightly less than limiting friction
[C] Kinetic friction is equal to limiting friction
[D] No relationship
Show Answer
Correct Answer: B [Kinetic friction is slightly less than limiting friction]
Notes:
The Kinetic friction is always slightly less than the limiting friction. This is because once the motion has started, the inertia of has been overcome and irregularities of one surface have little or no time to get locked into the irregularities of the other surface.
6. What is the coefficient of restitution for a perfectly elastic collision?
[A] 0
[B] 1
[C] -1
[D] 100
Show Answer
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.
7. Which of the following strains is produced in a body if the deforming force produces a change in the shape of the body without changing its volume?
[A] Linear
[B] Volumetric
[C] Shearing
[D] All of the above
Show Answer
Correct Answer: C [Shearing]
Notes:
If the deforming force produces a change in the shape of the body without changing its volume, the strain produced in the body is called as shearing strain. Shearing strain is defined as angle in radians through which a plane perpendicular to the fixed surface of the cubical body gets turned under the effect of tangential force.
8. What is the stress known as when there is a relative displacement between various layers of solid?
[A] Tangential
[B] Linear
[C] Lateral
[D] Longitudinal
Show Answer
Correct Answer: A [Tangential]
Notes:
When successive layers of solid move on each other i.e. when there is a relative displacement between various layers of solid, the stress produced is called as Tangential stress.
9. What do we call the maximum velocity of a fluid in a tube for which the flow remains streamlined?
[A] Hyper velocity
[B] critical velocity
[C] stream velocity
[D] laminar velocity
Show Answer
Correct Answer: B [critical velocity]
Notes:
The maximum velocity of a fluid in a tube for which the flow remains streamlined is called its critical velocity.
10. Which of the following represents angular frequency of a body?
[A] twice the frequency of the body
[B] product of frequency of the body with π
[C] half the frequency of the body
[D] product of frequency of the body with 3 π
Show Answer
Correct Answer: A [twice the frequency of the body]
Notes:
Angular frequency of a body executing periodic motion is equal to product of frequency of the body with factor 2π. Angular frequency = 2 π n The unit of Angular frequency will be rad per second.
