250+ TOP MCQs on Diesel Engine Fuel Supply System – Governor and Answers

Automotive Engine Auxiliary Systems Multiple Choice Questions on “Diesel Engine Fuel Supply System – Governor”

1. Based on which principle does the hydraulic governor works?
a) No inverting amplifier
b) Inverted hydraulic amplifier
c) Low pass filter
d) High pass filter
Answer: b
Clarification: A hydraulic governor for example the CAV works on the principle of an inverted hydraulic amplifier wherein a small pressure changes in some part of the system producing in some other part, an opposite change of much greater amplitude.

2. Which of the following is an example of a maximum speed governor?
a) Pneumatic governor
b) Mechanical governor
c) Hydraulic governor
d) Both hydraulic and pneumatic
Answer: b
Clarification: In a mechanical governor below this maximum speed, the control rack on the fuel injection pump may be directly operated by the driver through accelerator pedal and linkage, with a provision to override the driver control at maximum speed which is limited by the amount of spring tension. Such a governor is called the maximum speed governor.

3. Which of the following is not a part of a pneumatic governor?
a) Vacuum pipe
b) Venturi unit
c) Diaphragm
d) Glow plug
Answer: d
Clarification: The pneumatic governor consists of two main parts, the venturi unit, and the diaphragm unit. The venturi unit is connected to the engine inlet manifold and the diaphragm unit is fitted on the fuel injection pump. The two units are connected by a vacuum pipe.

4. The difference between which of the following is termed as governor overrun?
a) Between governor hysteresis and governor runoff
b) Between governor runoff and governor cut-in speed
c) Between governor cut-in speed and governor hysteresis
d) Between governor cut-off speed and governor cut-in speed
Answer: d
Clarification: Governor overrun is defined as the difference between the governor cut-off speed and the governor cut-in speed. Governor overrun is an important terminology in a governor along with governor hysteresis etc.

5. Which of the following links the accelerator pedal and pump control rack in a speed governor?
a) Governor
b) Venturi control unit
c) Fuel injector
d) Plunger
Answer: a
Clarification: The accelerator pedal and the pump control rack are linked only through the governor. The driver,then, changes spring tension with the help of the accelerator pedal and hence fix the speed of the engine in a vehicle.

6. What of the following gets actuated when the spring tension is adjusted and the fuel delivery decreases?
a) Control rack
b) Accelerator pedal
c) Cam
d) Sleeve
Answer: a
Clarification: The spring tension can be so adjusted as to actuate the control rack for a decrease in fuel delivery at some maximum speed. Below this maximum speed, the control rack on the fuel injection pump may be directly operated by the driver through accelerator pedal and linkage, with a provision to override the driver control at maximum speed which is limited by the spring tension.

7. Which of the following is defined as the speed of the fuel injection pump at which the control rod moves away from the maximum fuel to stop with the accelerator lever set for maximum speed?
a) Governor cut-off speed
b) Governor hysteresis
c) Governor run-off
d) Governor cut-in speed
Answer: d
Clarification: The terminology governor cut-in speed is the speed of the fuel injection pump at which the control rod just starts to move away from the maximum fuel stop with the accelerator lever set for maximum output.

8. Which of the following gives the drive to the governor shaft?
a) Motor
b) Engine
c) Alternator
d) Ignition coil
Answer: b
Clarification: The two spring-loaded weights are mounted on the governor shaft which gets its drive from the engine. At one end, the bell crank lever carries balls whereas their other ends touch the lower surface of the flange of a sleeve on the governor shaft.

9. Which of the following is defined as the percentage speed change when the control rod is moved by the governor from the maximum fuel delivery position to the no-fuel delivery position?
a) Governor hysteresis
b) Governor run-off
c) Governor cut-in speed
d) Governor cut-off speed
Answer: b
Clarification: The terminology governor run-off is defined as the percentage speed change when the control rod is moved by the governor from the maximum fuel delivery position to the no- fuel delivery position.

10. Which of the following controls the position of the butterfly valve in the venturi unit?
a) Motor
b) Spring
c) Accelerator pedal
d) Adjusting screw
Answer: c
Clarification: Accelerator pedal controls the position of the butterfly valve in the venturi unit and hence the amount of vacuum from the inlet manifold,which is applied to the diaphragm via the vacuum pipe. As the diaphragm is connected to the fuel pump control rack.

11. Which of the following is defined as the difference between the governor cutoff speed at which the fuel delivery stops with the increasing injection pump speed and the cut-off speed at which point fuel delivery just restarts with the decreasing injection pump speed?
a) Governor hysteresis
b) Governor run-off
c) Governor cut-in speed
d) Governor cut-off speed
Answer: a
Clarification: The terminology governor hysterisis defined as the difference between the governor cutoff speed at which the fuel delivery stops with the increasing injection pump speed and the cut-off speed at which point fuel delivery just restarts with the decreasing injection pump speed.

12. Which of the following helps in the idling spring adjustment?
a) Spring and lever
b) Camshaft
c) Rack and pinion
d) Gears meshed
Answer: a
Clarification: The idling spring adjustment is provided utilizing a separate spring and lever, the spring tension can be adjusted with an adjusting nut provided. Whereas the camshaft, rack, and pinion and gears have no operation in the idling spring.

13. As the engine speed increases, which force acts against the spring tension?
a) Rolling force
b) Friction force
c) Centrifugal force
D) Both rolling and friction force
Answer: c
Clarification: As the engine speed increases, the centrifugal force due to weights acts against the spring tension. Once the former exceeds the latter, the weights fly apart, causing the other ends of the bell crank levers to raise the sleeve.