Selected MCQ

Current Question
If the net external torque on a system is zero, which quantity is conserved?
  • A. Linear momentum only
  • B. Angular momentum
  • C. Kinetic energy only
  • D. Power
Correct Answer: B
Explanation:
Zero external torque implies conservation of total angular momentum.
Related Question 1
A body projected vertically upward from Earth’s surface neglecting air resistance will have which quantity conserved during flight if Earth’s rotation is neglected?
  • A. Kinetic energy only
  • B. Momentum only
  • C. Mechanical energy
  • D. Gravitational force
Correct Answer: C
Explanation:
In a uniform conservative gravitational field with no dissipation, total mechanical energy is conserved.
Related Question 2
A system with negative heat capacity is characteristic of:
  • A. Ideal gas
  • B. Black holes and self-gravitating systems
  • C. Solids
  • D. Liquids
Correct Answer: B
Explanation:
Adding energy can decrease temperature in gravitational systems.
Related Question 3
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 4
Which system controls reflex?
  • A. Digestive
  • B. Nervous
  • C. Respiratory
  • D. Circulatory
Correct Answer: B
Explanation:
Nervous system handles reflexes.
Related Question 5
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.