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Multiple choice question for engineering

Set 1

1. In a fuel-injection system, the amount of fuel delivered into the air stream going to the engine is controlled by a pump which forces the fuel under pressure.
a) True
b) False

View Answer

Answer: a

2. The requirements met by the injection system are:
a) Proper atomization of fuel into very fine droplets
b) Proper spray pattern to ensure rapid mixing of fuel and air
c) Uniform distribution of fuel droplets throughout the combustion chamber
d) All of the mentioned

View Answer

Answer: d

3. In an air injection system, __________ is forced into the cylinder by means of compressed air.
a) air
b) fuel
c) water
d) none of the mentioned

View Answer

Answer: b [Reason:] In an air injection system, generally fuel is forced into the cylinder by means of compressed air.

4. Fuel injector is used for
a) Gas engines
b) CI engines
c) SI engines
d) None of the mentioned

View Answer

Answer: b [Reason:] Fuel injector is used for CI engines and not for SI engine and gas engines.

5. Advantage of air injection system is
a) cheaper fuels can be used
b) mep is high
c) fine atomization and distribution of the fuel
d) all of the mentioned

View Answer

Answer: d

6. Commonly used injection system in automobiles is
a) air injection
b) solid injection
c) combination of (a) and (b)
d) none of the mentioned

View Answer

Answer: b

7. Fuel injection pressure in solid injection system is around
a) < 10 bar
b) 10-20 bar
c) 30-50 bar
d) 200-250 bar

View Answer

Answer: d

8. Fuel filters do not use generally
a) oil
b) paper
c) cloth
d) felt

View Answer

Answer: b [Reason:] Generally paper is not used as fuel filters.

9. Fuel is injected in a four-stroke CI engine
a) at the end of suction stroke
b) at the end of expansion stroke
c) at the end of compression stroke
d) at the end of exhaust stroke

View Answer

Answer: c

10. Advantage of fuel injection in SI engine is
a) low initial cost
b) low maintenance requirements
c) increased volumetric efficiency
d) none of the mentioned

View Answer

Answer: c

11. A six cylinder, four-stroke diesel engine develops 125 kW at 3000 rpm. Its brake specific fuel consumption is 200gm/kW h. Calculate the quantity of fuel to be injected per cycle per cylinder. Specific gravity of the fuel may be taken as 0.85.
a) 0.0545 cc/cycle
b) 0.545 cc/ cycle
c) 5.45 cc/cycle
d) none of the mentioned

View Answer

Answer: a [Reason:] Fuel consumed/hour = bsfc x Power output = 200 x 10-2 x 125 = 25 kg Fuel consumption/cylinder = 25/6 = 4.17 kg/h Fuel consumption/cycle = (Fuel consumption/minute)/n

where n = N/2 for four-stroke cycle engines = (4.17/60)/(3000/2) = 4.63 x 10-5 kg = 0.0463 gm Volume of fuel injected = 0.0463/0.85 = 0.0545 cc/cycle.

Set 2

1. The fuel is injected into the inlet manifold of each cylinder at _____________ timing.
a) same
b) different
c) unpredictable
d) none of the mentioned

View Answer

Answer: b [Reason:] The injection of fuel into the inlet manifold of each cylinder is at a different timing.

2. The timing at which the injection of the fuel takes place inside the inlet manifold is called _____________ timing.
a) injection
b) suction
c) combustion
d) none of the mentioned

View Answer

Answer: a [Reason:] Injection timing is defined as the timing at which the injection of the fuel takes place inside the inlet manifold.

3. In _____________ cylinder, the piston moves up from BDC to TDC during the exhaust stroke.
a) one
b) two
c) three
d) four

View Answer

Answer: a [Reason:] Only in one cylinder, the piston moves up from BDC to TDC during the exhaust stroke and not in two or three cylinder engines.

4. Just before the piston reaches TDC during exhaust stroke, injection of the fuel takes place into the inlet manifold of the cylinder at about 60º crankangle before TDC.
a) True
b) False

View Answer

Answer: a [Reason:] Yes, just before the piston reaches TDC during exhaust stroke, injection of the fuel takes place into the inlet manifold of the cylinder at about 60º crankangle before TDC.

5. At the beginning of the compression stroke, intake valve opens and the air fuel mixture is sucked into the cylinder during the suction stroke.
a) True
b) False

View Answer

Answer: b [Reason:] No, but at the beginning of the suction stroke, intake valve opens and the air fuel mixture is sucked into the cylinder during the suction stroke.

6. In the four cylinder engine, the ECU calculates the appropriate injection timing for each cylinder and the air fuel mixture is made available at each suction stroke.
a) True
b) False

View Answer

Answer: a [Reason:] yes, in the four cylinder engine, the ECU calculates the appropriate injection timing for each cylinder and the air fuel mixture is made available at each suction stroke.

7. In order to meet the operating conditions, the injection valve is kept open for a longer time by ECU.
a) True
b) False

View Answer

Answer: a [Reason:] Yes, in order to meet the operating conditions, the injection valve is kept open for a longer time by ECU.

8. In common rail fuel injection system, injection pressure is dependent of engine speed.
a) True
b) False

View Answer

Answer: b [Reason:] No, but in common rail fuel injection system, injection pressure is independent of engine speed.

Set 3

1. In a spark ignition engine combustion which is initiated between the spark plug electrodes spreads across the combustible mixture.
a) True
b) False

View Answer

Answer: a

2. A definite flame front is one which separates the fresh mixture from the products of combustion travels from the spark plug to the other end of the combustion chamber.
a) True
b) False

View Answer

Answer: a

3. The process of autoignition has nothing to do towards engine knock.
a) True
b) False

View Answer

Answer: b [Reason:] Actually, the process of autoignition leads towards engine knock.

4. In SI engine, ignition lag is reduced if the initial temperature and pressure are
a) decreased
b) increased
c) constant
d) none of the mentioned

View Answer

Answer: a [Reason:] In SI engine, due to the increment of the initial temperature and pressure are ignition lag is reduced.

5. Auto ignition refers to initiation of combustion without the necessity of a flame.
a) True
b) False

View Answer

Answer: a

6. The effects of knocking are
a) noise and roughness
b) mechanical damage
c) carbon deposits
d) all of the mentioned

View Answer

Answer: a [Reason:] The effects of knocking are i) noise and roughness ii) mechanical damage iii) carbon deposits iv) increase in heat transfer v) decrease in power output and efficiency vi) preignition.

7. The effects of knocking are
a) increase in heat transfer
b) decrease in power output and efficiency
c) preignition
d) all of the mentioned

View Answer

Answer: a [Reason:] The effects of knocking are i) noise and roughness ii) mechanical damage iii) carbon deposits iv) increase in heat transfer v) decrease in power output and efficiency vi) preignition.

8. Increase of pressure increases the self ignition temperature and the induction period.
a) True
b) False

View Answer

Answer: b [Reason:] In fact, increase of pressure decreases the self ignition temperature and the induction period.

9. Low engine speeds will give low turbulence and low flame velocities and knock may occur at low speed.
a) True
b) False

View Answer

Answer: a

10. Use of low octane fuel can eliminate detonation.
a) True
b) False

View Answer

Answer: b [Reason:] No, but the use of high octane fuel can eliminate detonation.

Set 4

1. The basic measurement and testing parameters are
a) friction power
b) indicated power
c) brake power
d) all of the mentioned

View Answer

Answer: d [Reason:] In order to achieve less cost of production, improve efficiency and power output, the important measurement and testing parameters are employed. These are a) friction power b) indicated power c) brake power d) fuel consumption e) air flow e) speed f) exhaust and coolant temperature g) emissions h) noise i) combustion phenomenon.

2. The basic measurement and testing parameters are
a) fuel consumption
b) air flow
c) speed
d) all of the mentioned

View Answer

Answer: d [Reason:] Same as above.

3. _____________ is the difference between indicated and brake power of an engine.
a) Air flow
b) Emissions
c) Friction power
d) None of the mentioned

View Answer

Answer: c [Reason:] The difference between the indicated and the brake power of an engine is defined as friction power, whereas air flow and emissions are related to combustion processes.

4. _____________ is also known as fuel rate extrapolation method.
a) Morse test
b) Motoring test
c) Willan’s line method
d) Retardation test

View Answer

Answer: c [Reason:] The another name for Willan’s line method is fuel rate extrapolation method.

5. The internal losses in an engine are
a) pumping losses
b) brake losses
c) combustion losses
d) all of the mentioned

View Answer

Answer: a [Reason:] There are only two internal losses, pumping losses and friction losses. During the inlet and exhaust stroke the gaseous pressure on the piston is greater on its forward side, hence during both strokes the piston must be moved against a gaseous pressure, and this causes pumping loss.

6. In Morse test, the engine is first run at the required speed by adjusting the throttle in ___________
a) CI engine
b) SI engine
c) all of the mentioned
d) none of the mentioned

View Answer

Answer: b [Reason:] While performing the morse test, the engine is first run at the required speed by adjusting the throttle in SI engine whereas the pump rack is adjusted in the CI engine.

7. The density of the fuel is dependent on temperature which can vary a wide range from ___________
a) 10 ºC to 70 ºC
b) -10 ºC to 70 ºC
c) 20 ºC to 80 ºC
d) -20 ºC to 80 ºC

View Answer

Answer: b [Reason:] Generally the density of the fuel is dependent on temperature which can vary a wide range from -10 ºC to 70 ºC giving rise to a error in measurement.

8. Larger range of flow can be measured without pressure head being too ___________ in a viscous flow meter.
a) small
b) large
c) deep
d) none of the mentioned

View Answer

Answer: b [Reason:] An advantage of viscous flow meter is that larger range of flow can be measured without pressure head being too small.

9. The indicated power for multi-cylinder engine will be same as that of a single cylinder engine.
a) True
b) False

View Answer

Answer: b [Reason:] The indicated power for multi-cylinder engine is always greater than that of a single cylinder engine.

10. If the speed of the engine is increased, the indicated power will
a) increase
b) decrease
c) remain same
d) none of the mentioned

View Answer

Answer: a [Reason:] Speed is directly proportional to indicated power, so when the speed of the engine is increased, the indicated power will also increase.

Set 5

1. The main purpose of the Multi-Point Fuel Injection system is to supply a proper ratio of gasoline and air to the cylinders.
a) True
b) False

View Answer

Answer: a

2. In the port injection arrangement, the injector is placed on the side of the intake manifold near the intake port.
a) True
b) False

View Answer

Answer: a

3. Types of Multi-Point Fuel Injection system are
a) port injection
b) throttle body injection
c) all of the mentioned
d) none of the mentioned

View Answer

Answer: c [Reason:] Types of Multi-Point Fuel Injection system are i) port injection ii) throttle body injection.

4. The Multi-Point Fuel Injection system can be functionally divided into
a) electronic control system
b) fuel system
c) air induction system
d) all of the mentioned

View Answer

Answer: c [Reason:] The Multi-Point Fuel Injection system can be functionally divided into the following three main components: i) electronic control system ii) fuel system iii) air induction system.

5. In MPFI-Electronic Control System, the sensors that monitor intake air temperature, the oxygen, the water temperature, the starter signal and the throttle position send signals to the ECU.
a) True
b) False

View Answer

Answer: a

6. In MPFI-Electronic Control System, the _____________ sensor sends information about the engine speed.
a) speed
b) ignition
c) air-flow
d) air-mass

View Answer

Answer: b [Reason:] In MPFI-Electronic Control System, the ignition sensor sends information about the engine speed and not speed, air flow and air mass sensors.

7. In MPFI-Electronic system, at the time of starting, the cold start injector is operated by the cold start injector time switch.
a) True
b) False

View Answer

Answer: b

8. In MPFI-Fuel system, the throttle receive signals from the ECU and inject the fuel into the intake manifold.
a) True
b) False

View Answer

Answer: b

9. In MPFI-Air Induction System, the air cleaner, the air flow meter, the throttle body and the air valve supply a proper amount of air to the air intake chamber and intake manifold.
a) True
b) False

View Answer

Answer: a

10. In MPFI-Fuel System, the quantity of air supplied is just what is necessary for complete combustion.
a) True
b) False

View Answer

Answer: b

11. In D-MPFI system, the fuel metering is regulated by the engine speed and the amount of air that actually enters the engine.
a) True
b) False

View Answer

Answer: b

12. In D-MPFI system, the vacuum in the intake manifold is first sensed.
a) True
b) False

View Answer

Answer: a