250+ TOP MCQs on IC Engine – Rocker Arms Design and Answers

Automotive Engine Components Design Multiple Choice Questions on “IC Engine – Rocker Arms Design”.

1. What is the basic function of the rocker arm, concerning the motion of the cam and follower?
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 or close the inlet or exhaust valve
Answer: d
Clarification: The basic function of the rocker arm, concerning the motion of the cam and follower, is to open or close the inlet or exhaust valve. This experience lot of heat.

2. To reduce the weight and inertia force of the rocker arm, which cross-section is used?
a) V-section
b) L-section
c) I-section
d) T-section
Answer: c
Clarification: To reduce the weight and inertia force of the rocker arm I-section cross-section is used. Whenever the inertia force is important, then I-section will be the first option.

3. Which of the mentioned below is not the material of rocker arm?
a) Grey-cast iron
b) Malleable cast iron
c) Chromium alloy
d) Cast steel
Answer: c
Clarification: Grey-cast iron, Malleable cast iron, Cast steel are all the material that is used in the manufacturing rocker-arm whereas chromium alloy is not usually used.

4. In a four-stroke engine, which valve is heavily loaded?
a) Exhaust
b) Inlet
c) Non-return
d) One way
Answer: a
Clarification: In a four-stroke engine, the exhaust valve is heavily loaded when compared to the inlet valve due to smaller in size and experience a lot of heat.

5. The force on which valve is less compared to others?
a) Non-return
b) Inlet
c) Ports
d) Exhaust
Answer: b
Clarification: In a four-stroke engine, the exhaust valve is heavily loaded when compared to the inlet valve and the force on the inlet valve is less comparing to the exhaust valve.

6. The maximum force exerted by the valve will determine which force on the rocker arm?
a) Torsional moment
b) Tangential moment
c) Bending moment
d) Both torsional and tangential moment
Answer: c
Clarification: The maximum force exerted by the valve will determine the bending moment on the rocker-arm. Hence, the bending moment is the right answer.

7. In the cross-section of the rocker arm, the bending moment is maximum at what point?
a) Centre of the pivot
b) Centre of gravity
c) Centre of mass
d) Centre of mass and pivot
Answer: a
Clarification: In the cross-section of the rocker arm, the bending moment is maximum at the Centre of the pivot point. Hence, the eye passing through this point is strengthened.

8. Which of the mentioned below is the formula to calculate the thickness of each eye?
a) t=(frac{l+h}{2})
b) t=(frac{V}{2})
c) t=(frac{l+v}{2})
d) t=(frac{l}{2})
Answer: d
Clarification: t=(frac{l}{2}) is the formula to calculate the thickness of each eye and D₂=2d₂is the formula to calculate the outer diameter of the eye. Hence, t=(frac{l}{2}) is the right answer.

9. Which of the mentioned below is the formula to calculate the outer diameter of the eye?
a) D₂=d₂
b) D₂=2d₂+2A₂
c) D₂=2d₂
d) A₂=2d₂+2
Answer: c
Clarification: t=(frac{l}{2}) is the formula to calculate the thickness of each eye and D₂=2d₂ is the formula to calculate the outer diameter of the eye. Hence, D₂=2d₂ is the right answer.

10. Which of the mentioned below is the formula to calculate the triangular distribution of the load between the pin and the eye?
a) x=(frac{l_2}{4})
b) x=(frac{l_2}{6})
c) x=(frac{l_2}{3})
d) x=l₂
Answer: b
Clarification: x=(frac{l_2}{6}) is the formula to calculate the triangular distribution of the load between the pin and the eye and D₂=2d₂ is the formula to calculate the outer diameter of the eye.

11. Which of the mentioned below is the formula to calculate uniformly distributed load between the pin and the roller?
a) Z=(frac{l_2}{4})
b) Z=(frac{l_2}{4})
c) x=(frac{l_2}{6})
d) x=l₂
Answer: b
Clarification: Z=(frac{l_2}{4})is the formula to calculate uniformly distributed load between the pin and the roller and t=(frac{l}{2}) is the formula to calculate the thickness of each eye.

12. Calculate the diameter of the circular end of the rocker, when d=15mm?
a) 40mm
b) 30mm
c) 45mm
d) 7.5mm
Answer: b
Clarification: D₃=2d
=2×15
=30mm