Relativity Quiz 1

Question 1

An aeroplane has a length of $$40	ext{ m}$$. When it is in flight mode, its length appears to be $$38	ext{ m}$$ for the eyes of a person at ground. Calculate the speed of the aeroplane.<img  src="https://cmds-vedantu.s3.ap-southeast-1.amazonaws.com/prod/question-sets/2186df7e-909d-4459-89b1-340bc454e0e54433129047466689124.png"/>

Accepted Answer

$$0.31\,c$$

Answer

$$0.13\,c$$

Answer

$$0.34\,c$$

Answer

$$0.43\,c$$

Question 2

A kid is playing with a plastic scale of length $$50	ext{ cm}$$. He projects it in the air in such a way that the scale moves parallel to its length. The length of the scale when its mass is three-fourth of its rest mass in metres is

Accepted Answer

$$0.66$$

Answer

$$0.50$$

Answer

$$0.56$$

Answer

None of these

Question 3

The relativistic factor for a particle of mass $$8	imes {{10}^{-20}}	ext{ kg}$$ is $$6.4$$.Determine the particle’s relativistic kinetic energy.

Accepted Answer

$$43.2\,{{c}^{2}}	imes {{10}^{-20}}$$

Answer

$$34.2\,{{c}^{2}}	imes {{10}^{-20}}$$

Answer

$$43.2\,{{c}^{2}}	imes {{10}^{-19}}$$

Answer

$$34.2\,{{c}^{2}}	imes {{10}^{-19}}$$

Question 4

The concept of relativity applies to both accelerated as well as unaccelerated motion. _ relativity handles with _ motion whereas _ relativity handles with _ motion only. In special relativity, a parameter called gamma factor_ plays the major role. This is also called the _ factor. It is given by _ where $$v$$ is the _ between inertial frames of reference and _ is the speed of light in vacuum.

Accepted Answer

General; accelerated; special; unaccelerated; $$\gamma $$; Lorentz; $$\dfrac{1}{\sqrt{1-\dfrac{{{v}^{2}}}{{{c}^{2}}}}}$$; relative velocity; $$c$$

Answer

Special; accelerated; general; unaccelerated; $$\gamma $$; Lambda; $$\dfrac{1}{\sqrt{1-\dfrac{{{c}^{2}}}{{{v}^{2}}}}}$$; velocity; $$c$$

Answer

General; accelerated; special; unaccelerated$$\gamma $$; Lambda; $$\dfrac{1}{\sqrt{1-\dfrac{{{v}^{2}}}{{{c}^{2}}}}}$$; relative velocity; $$c$$

Answer

Special; accelerated; general; unaccelerated; $$\gamma $$; Lorentz; $$\dfrac{1}{\sqrt{1-\dfrac{{{c}^{2}}}{{{v}^{2}}}}}$$; velocity; $$c$$

Question 5

An artificial celestial body sends information to the earth at a frequency $$1.5\,GHz$$, when it is moving away from the Earth at a speed of $$0.35\,c$$. Evaluate the frequency at which the information is received on the earth.

Accepted Answer

$$1.04\,GHz$$

Answer

$$2.04\,GHz$$

Answer

$$3.04\,GHz$$

Answer

$$4.04\,GHz$$