10 Question-Answer on theory of relativity
1. An inertial frame of reference is one
(a) Which remains at absolute rest
(b) Which remains in absolute motion
(c) Which does not accelerate
(d) Which may be attached to an observer
Ans: (c)
2. Which of the following is not assumed to be absolute in Newtonian mechanics?
(a) Mass
(b) Time
(c) Space
(d) State of rest or motion.
Ans: (d)
3. An event can be described by an observer in a cartesian frame of reference moving along X-axis with number of coordinates as
(a) 2
(b) 3
(c) 4
(d) 6
Ans: (c)
4. In which of the following frame of reference, the acceleration of the particle is zero in the absence of applied force?
(a) Inertial
(b) Non inertial
(c) Cartesian
(d) Non Cartesian
Ans: (a)
5. Which of the following is/are invariant under Galilean transformations?
(a) Speed
(b) Velocity
(c) Acceleration
(d) Momentum
Ans: (c)
6. Which of the following is /are variant under Galilean transformations?
(a) Mass
(b) Space
(c) Time
(d) Momentum
Ans: (d)
7. “all the inertial frames of reference are equivalent. This statement is called the principle of
(a) Inertia
(b) Relative motion
(c) Equivalence
(d) Correspondence
Ans: (b)
8. Two photons approach each other. Their relative velocity will be:
(a) 2c
(b) C
(c) c/2
(d) zero
Ans: (b)
9. a source of light moves with velocity c/2 towards a stationary observer. The observed speed of light is
(a) c
(b) c/2
(c) 3 c/2
(d) 2c
Ans: (a)
10. The apparent length of a meter stick, as measured by an observer at rest when the stick is moving along its length with a velocity 86.6% of velocity of light will be
(a) 0.20 m
(b) 0.35 m
(c) 0.50 m
(d) 6.5 m
Ans: (c)