250+ TOP MCQs on IC Engine – Valve-Gear Mechanism and Answers

Automotive Engine Components Design Multiple Choice Questions on “ IC Engine – Valve-Gear Mechanism”.

1. What is the function of the valve gear mechanism in the IC engine?
a) Only opening inlet and exhaust valve
b) Open and close the inlet and exhaust ports
c) Only closing inlet and exhaust valve
d) Open and close the inlet and exhaust valve
Answer: d
Clarification: The function of the valve gear mechanism in the IC engine is to open and close the inlet andexhaust valve. Open inlet valve to enter the charge and open exhaust valve to remove burnt gas.

2. The fuel is admitted into the cylinder, by opening which valve?
a) Exhaust
b) Ball port
c) Inlet
d) Non-return
Answer: c
Clarification: The fuel is admitted into the cylinder, by opening the inlet valve and the burnt gases escape from the engine by opening the exhaust valve. Inlet valve experience lesser then exhaust valve.

3. The burnt gases escape from the engine by opening which valve?
a) Inlet
b) Non-return
c) Exhaust
d) Inlet port
Answer: c
Clarification: The fuel is admitted into the cylinder, by opening the inlet valve and the burnt gases escape from the engine by opening the exhaust valve. Inlet valve experience lesser then exhaust valve.

4. Which of the parts mentioned below is not a part of the valve-gear mechanism?
a) Piston
b) Valve
c) Spring
d) Tappet
Answer: a
Clarification: Valve, spring, tappet are all part of a valve-gear mechanism, but the piston is the part that compresses the charge and experiences the heat that is present inside the cylinder.

5. The camshaft is rotated by which driving mechanism in cars?
a) Chain-drive
b) Belt-drive
c) Shaft-drive
d) Fluid drive
Answer: b
Clarification: The camshaft is rotated by Belt-drive mechanism in cars and this belt is also called a timing belt. In bikes, we have a timing chain supported by a torsion supporting bar.

6. As the camshaft rotates, the cam pushes the follower, and push rod is moved in which direction?
a) Downward
b) Parallel
c) Upward
d) Horizontal
Answer: c
Clarification: As the cam rotates,the cam pushes the follower, and push rod is moved in an upward direction and the rocker arm is pivoted at its centerutilizing Fulcrum pin.

7. The rocker arm is pivoted at its centerusing which pin?
a) Fulcrum
b) Key
c) Cotter
d) Spigot
Answer: a
Clarification: As the cam rotates,the cam pushes the follower, and pushrod is moved in an upward direction and the rocker arm is pivoted at its centerusing a Fulcrum pin.

8. When the right end of the rocker arm is pushed up, the left end moves in which direction?
a) Upward
b) Parallel
c) Perpendicular
d) Downward
Answer: d
Clarification: When the right end of the rocker arm is pushed up, the left end moves in a downward direction and pushes the spring-loaded valve to achieve the motion.

9. The opening of valves is due to which motion of the rocker arm?
a) Tangential motion
b) Reciprocating motion
c) Oscillatory motion
d) Rotating motion
Answer: c
Clarification: The opening of valves is due to the oscillatory motion of the rocker arm. This is due to the force by initial compression presses the valve down on its seat.

10. One end of the spring is secured to the valve stem and the other end rests on which part?
a) Piston
b) Cylinder
c) Oil pan
d) Cylinder head
Answer: b
Clarification: One end of the spring is secured to the valve stem and the other end rests on the cylinder. The cylinder is fixed support and withstands the high-pressure.

11. Follower rests on which part of the valve-gear mechanism?
a) Rocker-arm
b) Cam
c) Valve
d) Tappet
Answer: b
Clarification: One end of the spring is secured to the valve stem and the other end rests on the cylinder and the follower rests cams of the valve-gear mechanism.

12. What happens to the spring when the valve is opened?
a) Elongate
b) Compress
c) Twist
d) both compress and twist
Answer: b
Clarification: The spring gets compressed when valves are opened which means the cams are in action and push the push rod thereby rocker-arm. Depending on usage, the spring loses its strength.