Selected MCQ

Current Question
Which quantity is invariant in all reference frames?
  • A. Velocity
  • B. Time
  • C. Rest mass
  • D. Length
Correct Answer: C
Explanation:
Rest mass is Lorentz invariant.
Related Question 1
Which quantity remains invariant under Lorentz transformations?
  • A. Velocity
  • B. Time
  • C. Spacetime interval
  • D. Length
Correct Answer: C
Explanation:
The spacetime interval is invariant in all inertial frames.
Related Question 2
Which thermodynamic quantity remains constant in adiabatic process?
  • A. Temperature
  • B. Pressure
  • C. Entropy (reversible case)
  • D. Volume
Correct Answer: C
Explanation:
Reversible adiabatic process is isentropic.
Related Question 3
Which quantity is vector?
  • A. Mass
  • B. Speed
  • C. Velocity
  • D. Energy
Correct Answer: C
Explanation:
Velocity has magnitude and direction.
Related Question 4
Which quantity is scalar?
  • A. Velocity
  • B. Force
  • C. Acceleration
  • D. Energy
Correct Answer: D
Explanation:
Energy has magnitude only.
Related Question 5
The speed of light in vacuum is invariant because:
  • A. It depends on observer motion
  • B. It is defined constant in relativity
  • C. It varies with energy
  • D. It depends on medium
Correct Answer: B
Explanation:
Special relativity postulates constant light speed in all inertial frames.