# 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.

31. 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

32. What is the S.I unit of Pressure Energy?

[A] Nm

[B] Watt

[C] Joule

[D] No units

Show Answer

**Correct Answer:** C [ Joule ]

**Notes:**

Joule is the unit of Pressure energy. Pressure energy is the energy stored in a fluid due to the force per unit area applied onto it Pressure energy = Pressure x volume Its dimensional formula is M L^{2 }T^{-2}

33. Light year is a unit of which of these following?

[A] distance

[B] time

[C] pressure

[D] power

Show Answer

**Correct Answer:** A [ distance ]

**Notes:**

Light year is a unit of distance. One light year is the distance travelled by light in vacuum in one year. 1 light year = 9.46 x 10^{15 }m velocity of light in vacuum = 3 x10^{8 m/s}

34. Joule/kg is the S.I unit of which of these physical quantities?

[A] Entropy

[B] Permittivity of free space

[C] Latent heat

[D] Gas constant

Show Answer

**Correct Answer:** C [ Latent heat ]

**Notes:**

Joule/kg is the S.I unit of Latent heat Latent heat(L) = heat(Q)/mass(m) Latent heat is the heat required to convert a solid into a liquid or vapor, or a liquid into a vapor, without any change in temperature. Unit of Entropy: J/K Unit of Permittivity of free space: H/m Unit of Gas constant : J/K

35. The Newton’s third law is applicable when:

[A] bodies are at rest

[B] bodies are in motion

[C] bodies are in the air

[D] bodies are at rest or in motion

Show Answer

**Correct Answer:** D [bodies are at rest or in motion]

**Notes:**

The Newton’s third law is applicable whether the bodies are at rest or in motion. It states that to every action there is an equal and opposite reaction.

36. The second law of motion gives us a measure of which of the following physical quantities?

[A] Acceleration

[B] Force

[C] Power

[D] Work done

Show Answer

**Correct Answer:** B [Force]

**Notes:**

The second law of motion gives us a measure of force. The product of the mass of the body and the acceleration produced in it gives us the magnitude of force. Force (f) = mass (m) x acceleration (a) Force is a vector quantity and the direction is same as that of acceleration

37. Which of the following statements is correct about the value of acceleration due to gravity (g) in a light and heavy falling body?

[A] the value of g will be greater in the light body

[B] the value of g will be greater in the heavy body

[C] the value of g will be equal in both the bodies

[D] the value of g depends on the mass

Show Answer

**Correct Answer:** C [the value of g will be equal in both the bodies]

**Notes:**

Acceleration due to gravity is independent of mass, shape, size etc. of falling body. Therefore, a light and heavy body will have equal acceleration.

38. What is the value of Universal Gravitational Constant?

[A] 6.67×10^{-9} N–m2 kg–2

[B] 6.67×10^{-10} N–m2 kg–2

[C] 6.67×10^{11} N–m2 kg–2

[D] 6.67×10^{-11} N–m2 kg–2

Show Answer

**Correct Answer:** D [6.67×10^{-11} N–m2 kg–2]

**Notes:**

The value of Universal Gravitational Constant is same throughout the universe and is equal to 6.67×10^{-11} Nm^{2} kg^{-2} in S.I. and 6.67×10^{-8} dyne cm^{2} g^{-2}

39. The acceleration due to gravity on any planet does not depend on which of the following?

[A] Radius of the planet

[B] Mass of the planet

[C] Density of the planet

[D] Mass of the object

Show Answer

**Correct Answer:** D [Mass of the object]

**Notes:**

The value of acceleration due to gravity on any planet depends upon the mass radius and density of planet and it is independent of mass, shape and density of the body placed on the surface of the planet.

40. On which of the following the escape velocity of a body does not depend?

[A] Mass of the body

[B] Radius of the planet

[C] Mass of the planet

[D] None of the above

Show Answer

**Correct Answer:** A [Mass of the body]

**Notes:**

The escape velocity is independent of the mass and angle of projection of the body. Escape velocity depends on the mass and radius of the planet from the surface of which the body is to be projected.

Advertisement
[contact-form-7 id="141158" title="Contact form 1"]