250+ TOP MCQs on IC Engine – Valves Design and Answers

Automotive Engine Design Questions and Answers for Experienced people on “IC Engine – Valves Design”.

1. Which are the two types of valves?
a) Sleeve and tapper valve
b) Mushroom and ball valve
c) Tapper and ball valve
d) Mushroom and sleeve valves
Answer: d
Clarification: Mushroom and sleeve valves are the two types of valves used in the internal combustion engines and the mushroom valves are also known as poppet valves.

2. What are the mushroom valves also known as?
a) Tapper valve
b) Sleeve valve
c) Poppet valve
d) Non-return valve
Answer: c
Clarification: Mushroom valves are also known as poppet valves. Since it consists of a stem and one end enlarged to form a head that permits the flow through a passage surrounding the stem, that resembles the shape of a mushroom.

3. What does the poppet valve consisting of a disk known as?
a) Face
b) Stem
c) Head
d) Shank
Answer: c
Clarification: The poppet valve that consists of a disk known as head and the poppet valve head at the end of a rod is known as the stem. Stem experience lesser heat compared to the face of the valve.

4. What is the poppet valve head at the end of a rod is known as?
a) Stem
b) Face
c) Head
d) Shank
Answer: a
Clarification: The poppet valve that consists of a disk known as head and the poppet valve head at the end of a rod is known as the stem. This experience lesser heat compared to the face of the valve.

5. Which part of the valve is a conical surface that comes in contact with a valve seat?
a) Head
b) Face
c) Stem
d) shank
Answer: b
Clarification: The poppet valve that consists of a disk known as the head, the poppet valve head at the end of a rod is known as stem and the valve is a conical surface that comes in contact with a valve seat known as a face.

6. What is the face angle range for a poppet valve?
a) 20° to 50°
b) 35° to 60°
c) 30° to 45°
d) 40° to 55°
Answer: c
Clarification: 30° to 45° is the face angle range for a poppet valve. The face angle and the face can be altered accordingly using grinding or skimming machines.

7. What is the small conical surface of the valve results in which property?
a) Self-centering
b) Increase in weight
c) Hardness
d) Strength
Answer: a
Clarification: The small conical surface of the valve results in Self-centering. This is one of the important properties if this neglected, the charge won’t be compressed properly.

8. What is the small space between the head and the face is known as?
a) Blank
b) Space
c) Stem
d) Margin
Answer: d
Clarification: The small space between the head and the face is known as margin and the poppet valve head at the end of a rod is known as the stem. The margin contributes to improve airflow and durability.

9. In heavy-duty engines, which material is used in the valves?
a) Silicon-Chromium steel
b) Nickel-Chromium steel
c) Chromium-vanadium steel
d) Hardened steel
Answer: c
Clarification: In heavy-duty engines, the valves are made by chromium-vanadium steel and in normal cars, nickel-Chromium steelor silicon-Chromium steel are used.

10. Which material is used in the Inlet valves?
a) Chromium-vanadium steel
b) Nickel-Chromium steel
c) Silicon-Chromium steel
d) Hardened steel
Answer: b
Clarification: Inlet valves are made of Nickel-Chromium steel and exhaust valves are made of Silicon-Chromium steel. In heavy-duty engines, the valves are made by chromium-vanadium steel.

11. Which material is used Exhaust valves?
a) Hardened steel
b) Silicon-Chromium steel
c) Nickel-Chromium steel
d) Chromium-vanadium steel
Answer: b
Clarification: Inlet valves are made of Nickel-Chromium steel and exhaust valves are made of Silicon-Chromium steel. In heavy-duty engines, the valves are made by chromium-vanadium steel.

12. By which process valves are strengthened?
a) Heat-treated
b) Both heat treated and surface hardening
c) Surface hardening
d) Quenching
Answer: b
Clarification: Valves are strengthened by both heat treating and surface hardening for inlet and exhaust at the temperature in the range 250 to 300HB.

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