250+ TOP MCQs on Engine Management Systems and Answers

IC Engines Multiple Choice Questions on “Engine Management Systems”.

1. Which of the following is the main aim of an engine management system to achieve?
a) high reliability and durability with lowest possible initial cost
b) high power output and torque
c) low levels of gaseous and particulate emissions
d) all of the mentioned
Answer: d
Clarification: The main aims of an engine management system is to achieve
i) high reliability and durability with lowest possible initial cost
ii) high power output and torque
iii) low levels of gaseous and particulate emissions
iv) low fuel consumption
v) low noise levels and vibrations.

2. What are the important parameters in a gasoline engine that can be controlled?
a) air-fuel ratio
b) mixture distribution between cylinders
c) ignition timing
d) all of the mentioned
Answer: d
Clarification: The important parameters in a gasoline engine that can be controlled are
i) air-fuel ratio
ii) mixture distribution between cylinders
iii) ignition timing
iv) injection timing of the fuel
v) idle speed.

3. Hall effect pickup use ______________
a) inductive transducers
b) potentiometers
c) thermistors
d) semiconductors
Answer: d
Clarification: Hall effect pickup is a transducer that varies its output voltage in response to a magnetic field. Hall effect sensors are used for proximity switching, positioning, speed detection, and current sensing application and thus it uses semiconductor.

4. LVDT is used to measure ______________
a) crank angle
b) engine speed
c) large displacements
d) gas temperature
Answer: c
Clarification: To measure large displacements, LVDT is used.

5. What is the disadvantage of the piezoelectric pressure pickup?
a) it can only give pressure difference
b) it can measure only low pressure
c) it is not suitable for dynamic measurement
d) has too much sensitivity
Answer: a
Clarification: By using piezoelectric pressure pickup only the pressure difference can be measured and not the low pressure.

6. Thermistors are desirable because of their ______________
a) linear output
b) large temperature coefficient
c) suitability for high temperature
d) none of the mentioned
Answer: b
Clarification: Only thermistors have the property to give large temperature coefficients.

7. Seebeck effect is used in ______________
a) thermistors
b) thermocouples
c) rtd
d) hot-wire sensor
Answer: b
Clarification: Seebeck effect is a property in thermocouples and not in thermistors and RTD.

8. Hot-wire sensors are used for the measurement of ______________
a) temperature
b) pressure
c) mass flow rate
d) smoke intensity
Answer: c
Clarification: Only mass flow rate is measured by using hot-wire sensors.

9. Knock sensors use ______________
a) thermistors
b) thermocouples
c) piezoelectric pickup
d) flap type sensors
Answer: c
Clarification: In piezoelectric pickup knock sensors are used while seebeck effect is used in thermocouples.

10. Catalytic converters use lambda sensors to keep ______________
a) exhaust temperature constant
b) exhaust pressure constant
c) excess air ratio within a range
d) flow rate of air constant
Answer: c
Clarification: Only lambda sensors are used in catalytic converters to keep excess air ratio within a range.