# General Science - Physics MCQs

Physics Objective (Multiple Choice) General Knowledge & General Science Questions & Answers for SSC-CGL, UPPSC, UPSC, NDA, CDS and UPSC Civil Services Prelims Examinations.

11. Which of the following is the unit of Solid Angle?

[A] radian

[B] steradian

[C] m^{2}

[D] π

Show Answer

**Correct Answer:** B [ steradian ]

**Notes:**

Steradian is the unit of Solid Angle (Angle in Space). One steradian is defined as the solid angle of a sphere subtended at the centre of a sphere by that surface of the surface whose area is equal to the square of the sphere’s radius. Its symbol is sr.

12. 1 nautical mile is equivalent to which of the following?

[A] 1.44 x 1000 m

[B] 1.852 x 100 m

[C] 1.852 x 1000 m

[D] 1.44 x 100 m

Show Answer

**Correct Answer:** C [ 1.852 x 1000 m ]

**Notes:**nautical mile is a unit of length. 1 nautical mile is equal to 1.852 x 1000 m Other important units of length are:

- 1 mile = 1.609 x 1000 m
- 1 light year = 9.46 x 10
^{15} m
- 1 AU = 1.5 x 10
^{11}m
- 1 Par sec = 3.1 x 10
^{16}m

13. 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

14. Which of these pairs has the same unit of measurement?

[A] Rate of flow and Acceleration

[B] Impulse and Moment of Force

[C] Rydberg constant and Gas constant

[D] Pressure and Coefficient of Elasticity

Show Answer

**Correct Answer:** D [ Pressure and Coefficient of Elasticity ]

**Notes:**

Pressure and Coefficient of Elasticity have the same unit i.e. N m^{-2} (Newton per metre square) Other important units: Rate of Flow: m^{3}s^{-1} Acceleration: ms^{-2} Rydberg constant: 1/m Gas constant: J/K Impulse: Ns Moment of Force: Nm

15. Which of the following represents non-uniform motion?

[A] equal displacements in unequal intervals of time

[B] unequal displacements in unequal intervals of time

[C] equal displacements in equal intervals of time

[D] unequal displacements in equal intervals of time

Show Answer

**Correct Answer:** A [equal displacements in unequal intervals of time]

**Notes:**

An object is said to be in non-uniform motion if it undergoes equal displacements in unequal intervals of time. In non-uniform motion, the velocity is different at different instants.

16. What is the slope of the velocity-time graph when an object moves with constant negative acceleration, having positive initial velocity?

[A] 90°

[B] more than 90°

[C] less than 90°

[D] 0°

Show Answer

**Correct Answer:** B [more than 90°]

**Notes:**

When an object moves with constant negative acceleration, having positive initial velocity, the velocity-time graph is a straight line having slope more than 90°. When an object moves with constant positive acceleration, having positive initial velocity, the velocity-time graph is a straight line having slope less than 90°.

17. 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.

18. Which of the following are Polar vectors?

[A] Displacement

[B] Force

[C] Both a and b

[D] None

Show Answer

**Correct Answer:** C [Both a and b]

**Notes:**

The polar vectors are those vectors which have a starting point or a point of application. Examples of Polar vector: Force, Displacement etc. Those vectors which represent rotational effect are called as axial vectors. Example: Angular velocity, Torque, Angular Momentum etc.

19. What is the work done by centripetal force in case of Uniform Circular Motion?

[A] 1 joule

[B] 0 joule

[C] Depends on the magnitude of Force

[D] None of the above

Show Answer

**Correct Answer:** B [0 joule]

**Notes:**

The work done by Centripetal Force in case of Uniform Circular Motion is zero. The displacement and force are mutually perpendicular to each other in case of centripetal force. Therefore the work done is zero.

20. What is the angular acceleration of a body moving with constant angular velocity?

[A] equal to the angular velocity

[B] 1

[C] 0

[D] Can’t be determined

Show Answer

**Correct Answer:** C [0]

**Notes:**

The angular acceleration of a body moving with constant angular velocity is 0. Angular acceleration of an object in circular motion is defined as the time rate of change of its angular velocity.

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