Mechanical Engineering MCQs

11. Which process is used to harden the surface of steel while keeping its core soft?
A. Annealing
B. Quenching
C. Case Hardening
D. Tempering
12. Which thermodynamic cycle is used in jet engines?
A. Otto Cycle
B. Diesel Cycle
C. Brayton Cycle
D. Rankine Cycle
13. Which component in an IC engine regulates the entry of fuel-air mixture into the cylinder?
A. Piston
B. Crankshaft
C. Camshaft
D. Valve
14. Which law states that the strain in a solid is proportional to the applied stress?
A. Boyle’s Law
B. Hooke’s Law
C. Pascal’s Law
D. Charles’ Law
15. What is the primary purpose of a heat exchanger?
A. To store heat
B. To transfer heat
C. To generate heat
D. To insulate heat
16. Which of the following is a type of thermodynamic process?
A. Isothermal
B. Adiabatic
C. Isochoric
D. All of the above
17. What is the main function of a governor in an engine?
A. Control speed
B. Increase power
C. Reduce emissions
D. Regulate temperature
18. Which material has the highest thermal conductivity?
A. Copper
B. Aluminum
C. Steel
D. Wood
19. What is the main purpose of a bearing?
A. To reduce friction
B. To increase friction
C. To support weight
D. To transmit power
20. What is the term for the ratio of the output power to the input power in a machine?
A. Efficiency
B. Power factor
C. Torque
D. Work