SPECIAL RELATIVITY EXAM QUESTION
AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which postulate states that the laws of physics are the same in all inertial
frames?
A. Principle of equivalence
B. Constancy of light speed
C. Relativity principle
D. Galilean invariance
Answer: C
Rationale: The first postulate of special relativity asserts that all inertial
observers measure the same physical laws.
2. What is the value of the speed of light in vacuum?
A. 3 × 10⁶ m/s
B. 3 × 10⁷ m/s
C. 3 × 10⁸ m/s
D. 3 × 10⁹ m/s
Answer: C
Rationale: The speed of light in vacuum is a universal constant equal to 3 ×
10⁸ m/s.
3. Which transformation replaces Galilean transformations in special
relativity?
A. Fourier transformation
B. Lorentz transformation
C. Laplace transformation
, D. Gauge transformation
Answer: B
Rationale: Lorentz transformations correctly relate space and time
coordinates between inertial frames moving at relativistic speeds.
4. Time dilation implies that a moving clock runs
A. Faster
B. Slower
C. At the same rate
D. Irregularly
Answer: B
Rationale: Observers measure moving clocks to tick more slowly
compared to clocks at rest.
5. Length contraction affects objects
A. Parallel to motion
B. Perpendicular to motion
C. In all directions
D. Only at rest
Answer: A
Rationale: Length contraction occurs only along the direction of relative
motion.
6. The Lorentz factor γ is defined as
A. v/c
B. √(1 − v²/c²)
C. 1/√(1 − v²/c²)
D. √(1 + v²/c²)
Answer: C
Rationale: The Lorentz factor quantifies relativistic effects and increases
with velocity.
7. When v ≪ c, relativistic mechanics reduces to
A. Quantum mechanics
B. Classical mechanics
, C. Statistical mechanics
D. Field theory
Answer: B
Rationale: At low velocities, relativistic equations approximate classical
Newtonian results.
8. Simultaneity in special relativity is
A. Absolute
B. Relative
C. Undefined
D. Classical
Answer: B
Rationale: Events simultaneous in one frame may not be simultaneous in
another moving frame.
9. Proper time is measured in the frame where
A. The observer is moving
B. The event occurs at the same location
C. The observer accelerates
D. Time is dilated
Answer: B
Rationale: Proper time is measured by a clock at rest relative to the
events.
10.Proper length is measured
A. In any inertial frame
B. In the frame where the object is moving
C. In the rest frame of the object
D. In an accelerated frame
Answer: C
Rationale: Proper length is the length measured in the object’s rest frame.
11.Which invariant quantity remains the same in all inertial frames?
A. Velocity
B. Time interval
AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A
INSTANT DOWNLOAD PDF
1. Which postulate states that the laws of physics are the same in all inertial
frames?
A. Principle of equivalence
B. Constancy of light speed
C. Relativity principle
D. Galilean invariance
Answer: C
Rationale: The first postulate of special relativity asserts that all inertial
observers measure the same physical laws.
2. What is the value of the speed of light in vacuum?
A. 3 × 10⁶ m/s
B. 3 × 10⁷ m/s
C. 3 × 10⁸ m/s
D. 3 × 10⁹ m/s
Answer: C
Rationale: The speed of light in vacuum is a universal constant equal to 3 ×
10⁸ m/s.
3. Which transformation replaces Galilean transformations in special
relativity?
A. Fourier transformation
B. Lorentz transformation
C. Laplace transformation
, D. Gauge transformation
Answer: B
Rationale: Lorentz transformations correctly relate space and time
coordinates between inertial frames moving at relativistic speeds.
4. Time dilation implies that a moving clock runs
A. Faster
B. Slower
C. At the same rate
D. Irregularly
Answer: B
Rationale: Observers measure moving clocks to tick more slowly
compared to clocks at rest.
5. Length contraction affects objects
A. Parallel to motion
B. Perpendicular to motion
C. In all directions
D. Only at rest
Answer: A
Rationale: Length contraction occurs only along the direction of relative
motion.
6. The Lorentz factor γ is defined as
A. v/c
B. √(1 − v²/c²)
C. 1/√(1 − v²/c²)
D. √(1 + v²/c²)
Answer: C
Rationale: The Lorentz factor quantifies relativistic effects and increases
with velocity.
7. When v ≪ c, relativistic mechanics reduces to
A. Quantum mechanics
B. Classical mechanics
, C. Statistical mechanics
D. Field theory
Answer: B
Rationale: At low velocities, relativistic equations approximate classical
Newtonian results.
8. Simultaneity in special relativity is
A. Absolute
B. Relative
C. Undefined
D. Classical
Answer: B
Rationale: Events simultaneous in one frame may not be simultaneous in
another moving frame.
9. Proper time is measured in the frame where
A. The observer is moving
B. The event occurs at the same location
C. The observer accelerates
D. Time is dilated
Answer: B
Rationale: Proper time is measured by a clock at rest relative to the
events.
10.Proper length is measured
A. In any inertial frame
B. In the frame where the object is moving
C. In the rest frame of the object
D. In an accelerated frame
Answer: C
Rationale: Proper length is the length measured in the object’s rest frame.
11.Which invariant quantity remains the same in all inertial frames?
A. Velocity
B. Time interval
