Selected MCQ

Current Question
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.
Related Question 1
Which wave travels in vacuum?
  • A. Sound
  • B. Water
  • C. Light
  • D. Seismic
Correct Answer: C
Explanation:
Light does not require medium.
Related Question 2
Which instrument measures wind speed?
  • A. Hygrometer
  • B. Anemometer
  • C. Barometer
  • D. Thermometer
Correct Answer: B
Explanation:
Anemometer measures wind velocity.
Related Question 3
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 4
The wavefunction of a particle must be continuous because:
  • A. It represents force
  • B. Its square gives probability density
  • C. It represents velocity
  • D. It defines temperature
Correct Answer: B
Explanation:
Discontinuity would imply undefined probability.
Related Question 5
Which phenomenon bends light?
  • A. Reflection
  • B. Refraction
  • C. Diffraction
  • D. Interference
Correct Answer: B
Explanation:
Refraction changes direction in medium.