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Objective Type Set
Online MCQ Assignment
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Multiple choice question for engineering

Set 1

1. Piston type pump is used for low speed and single or two cylinder engines.
a) True
b) False

View Answer

Answer: a

2. Centrifugal blower is used for small and medium engines.
a) True
b) False

View Answer

Answer: b [Reason:] In fact, roots blower is used for small and medium engines.

3. Centrifugal blower is employed for large and high output engines.
a) True
b) False

View Answer

Answer: a

4. Scavenging systems, based on charge flow are classifies as
a) uniflow
b) loop or reverse scavenging
c) cross scavenging
d) all of the mentioned

View Answer

Answer: d [Reason:] Scavenging systems, based on charge flow are classifies as a) uniflow b) loop or reverse scavenging c) cross scavenging.

5. Pressure loss co-efficient is defined as the ratio between the main upstream and downstream pressures during the scavenging period.
a) True
b) False

View Answer

Answer: a

6. __________ scavenging system has the highest efficiency.
a) Loop or reverse
b) Uniflow
c) Cross
d) None of the mentioned

View Answer

Answer: b [Reason:] Of all the above only uniflow scavenging system has the highest efficiency.

7. In __________ scavenging, the fresh air first sweeps across the piston top, moves up and then down finally out through the exhaust.
a) loop
b) uniflow
c) cross
d) none of the mentioned

View Answer

Answer: a

8. In __________ scavenging system the inlet and exhaust ports are located on opposite sides of the cylinder.
a) loop
b) uniflow
c) cross
d) none of the mentioned

View Answer

Answer: c

9. Crankcase scavenging arrangement is very economical and inefficient in operation.
a) True
b) False

View Answer

Answer: b [Reason:] Actually, crankcase scavenging arrangement is very uneconomical and inefficient in operation.

10. Scavenging process consists of
a) pre-blowdown stages
b) blowdown
c) scavenging
d) all of the mentioned

View Answer

Answer: d [Reason:] Scavenging process consists of a) pre-blowdown stages b) blowdown stages c) scavenging d) additional charging.

Set 2

1. The purpose of the spark advance mechanism is to assure that under every condition of engine operation, ignition takes place at the most favourable instant in time.
a) True
b) False

View Answer

Answer: a

2. The engine speed and the engine load are the control quantities required for the automatic adjustment of the ignition timing.
a) True
b) False

View Answer

Answer: a

3. The vacuum advance mechanism controls the ignition timing for full load operation.
a) True
b) False

View Answer

Answer: b [Reason:] In fact, the centrifugal advance mechanism controls the ignition timing for full load operation.

4. Vacuum advance mechanism shifts the ignition point under ____________ load operation.
a) full
b) part
c) no
d) none of the mentioned

View Answer

Answer: b

5. The vacuum advance mechanism operates depending on the centrifugal advance mechanism.
a) True
b) False

View Answer

Answer: b [Reason:] Actually, the vacuum advance mechanism operates independent of the centrifugal advance mechanism.

6. The larger throttle opening means the possibility of better mixing and combustion during idling.
a) True
b) False

View Answer

Answer: a

7. It is necessary to have centrifugal advance of the spark timing since the lean mixtures require an earlier spark timing than the rich mixtures.
a) True
b) False

View Answer

Answer: b [Reason:] Actually, it is necessary to have vacuum advance of the spark timing since the lean mixtures require an earlier spark timing than the rich mixtures.

8. The ignition advance is obtained with the help of a spring loaded diaphragm connected to the
a) throttle
b) nozzle
c) venturi
d) none of the mentioned

View Answer

Answer: c [Reason:] The ignition advance is obtained with the help of a spring loaded diaphragm connected to the venturi and spring is not connected to nozzle or throttle.

9. The diaphragm is so coupled with the contact breaker that when induction pressure is reduced, the angle of advance
a) decreases
b) increases
c) remains constant
d) none of the mentioned

View Answer

Answer: b

10. The centrifugal spark advance is essential to compensate for the increase in speed of the engine.
a) True
b) False

View Answer

Answer: a

Set 3

1. Supercharging of S.I engines is employed only for aircraft and racing car engines.
a) True
b) False

View Answer

Answer: a [Reason:] Supercharging requires when speed is taken in consideration so, supercharging of S.I engines is employed only for aircraft and racing car engines.

2. ____________ in supercharging pressure increases the tendency to detonate and pre-ignite.
a) Decrease
b) Increase
c) Unpredictable
d) None of the mentioned

View Answer

Answer: a [Reason:] Detonation and pre-ignition are increased by increase in supercharging pressure.

3. The supercharged petrol engines have a lower fuel consumption than naturally aspirated engines.
a) True
b) False

View Answer

Answer: b [Reason:] Actually, the supercharged petrol engines have a greater fuel consumption than naturally aspirated engines.

4. Increased intake pressure and temperature reduces ignition delay and decreases flame speed.
a) True
b) False

View Answer

Answer: b [Reason:] In fact, increased intake pressure and temperature reduces ignition delay and increases flame speed.

5. The increased flame speeds make the petrol engine more sensitive to fuel-air ratio and engine cannot run on strong mixtures without knock.
a) True
b) False

View Answer

Answer: b [Reason:] Actually, the increased flame speeds make the petrol engine more sensitive to fuel-air ratio and engine cannot run on weak mixtures without knock.

6. Rich mixtures are used to control detonation, which further increases the specific fuel consumption of the engine.
a) True
b) False

View Answer

Answer: a

7. The ignition timings and thermal load on the engine affect the knock limit of CI engine.
a) True
b) False

View Answer

Answer: b [Reason:] No, in fact the ignition timings and thermal load on the engine affect the knock limit of SI engine.

8. The ignition must be retarded at high intake pressure and temperature.
a) True
b) False

View Answer

Answer: a

9. The power developed by the turbocharger is not sufficient to drive the compressor, and overcome its mechanical friction.
a) True
b) False

View Answer

Answer: b [Reason:] In fact, the power developed by the turbocharger is sufficient to drive the compressor, and overcome its mechanical friction.

10. The loss in piston work due to early opening of the exhaust valve is less than offset by better charging and scavenging of the engine.
a) True
b) False

View Answer

Answer: b [Reason:] No, in fact, the loss in piston work due to early opening of the exhaust valve is more than offset by better charging and scavenging of the engine.

Set 4

1. Pollutants are produced by the incomplete burning of the air-fuel mixture in the combustion chamber.
a) True
b) False

View Answer

Answer: a

2. The major pollutants emitted from the exhaust due to incomplete combustion are
a) carbon monoxide
b) hydrocarbons
c) oxides of nitrogen
d) all of the mentioned

View Answer

Answer: d [Reason:] The major pollutants emitted from the exhaust due to incomplete combustion are a) carbon monoxide b) hydrocarbons c) oxides of nitrogen.

3. _____________is a colourless gas of about the same density of air.
a) Carbon monoxide
b) Hydrocarbons
c) Oxides of nitrogen
d) All of the mentioned

View Answer

Answer: a [Reason:] No other gas except carbon monoxide, is a colourless gas of the same density as of air while hydrocarbons and nitrogen oxides have different densities.

4. Carbon monoxide is a poisonous gas which, when inhaled, replaces the oxygen in the blood stream so that the body’s metabolism can not function correctly.
a) True
b) False

View Answer

Answer: a

5. Large amounts of CO concentrations, when breathed in, slow down physical and mental activity and produces headaches, while large concentration will kill.
a) True
b) False

View Answer

Answer: b [Reason:] No, even a small amount of CO concentrations, when breathed in, slow down physical and mental activity and produces headaches, while large concentration will kill.

6. The amount of CO formed ______________ as the mixture becomes more and more rich in fuel.
a) decreases
b) increases
c) remains same
d) none of the mentioned

View Answer

Answer: b [Reason:] The concentration of CO is directly proportional to the mixture, that is why the amount of CO formed increases as the mixture becomes more and more rich in fuel.

7. A small amount of CO will come out of the exhaust even when the mixture is slightly lean in fuel.
a) True
b) False

View Answer

Answer: a

8. As the products cool down to exhaust temperature, minor part of CO reacts with oxygen to form Co2.
a) True
b) False

View Answer

Answer: b [Reason:] No, but in fact, as the products cool down to exhaust temperature, major part of CO reacts with oxygen to form Co2.

9. If the combustion is complete, the only products being expelled from the exhaust would be water vapour and carbondioxide.
a) True
b) False

View Answer

Answer: a

10. Air pollution is defined as an addition to our atmosphere of any material which will have a deleterious effect on life upon our planet.
a) True
b) False

View Answer

Answer: a

Set 5

1. The difference between I.P. and B.P. is known as total engine friction loss.
a) True
b) False

View Answer

Answer: a

2. In four stroke cycle engines, an ample amount of ____________ is used during intake and exhaust processes.
a) heat
b) pressure
c) power
d) none of the mentioned

View Answer

Answer: c

3. The pumping loss is negligible in two-stroke cycle engines.
a) True
b) False

View Answer

Answer: a [Reason:] The pumping loss is negligible in two-stroke cycle engines since the incoming fresh mixture is used for scavenging the exhaust gases and charging the cylinder.

4. The standard practice for sizing the exhaust valve is to make them a certain percentage ____________ than the inlet valves.
a) larger
b) smaller
c) unpredictable
d) none of the mentioned

View Answer

Answer: b

5. If due attention is not given to the valve size, valve timing and valve flow coefficients there may be a substantial loss with the increase in engine speed.
a) True
b) False

View Answer

Answer: a

6. The exhaust throttling loss occurs due to the restrictions imposed by air cleaner, carburetor venturi, throttle valve, intake manifold and intake valve.
a) True
b) False

View Answer

Answer: b [Reason:] The inlet throttling loss occurs due to the restrictions imposed by air cleaner, carburetor venturi, throttle valve, intake manifold and intake valve.

7. Combustion chamber pump loss is caused due to the pumping work required to pump gases into and out of the pre-combustion chamber.
a) True
b) False

View Answer

Answer: a

8. ____________ losses are caused due to the leakage of combustion products past the piston from the cylinder into the crankcase.
a) Pumping
b) Blowby
c) Pressure
d) None of the mentioned

View Answer

Answer: b

9. Blowby losses ____________ directly with compression ratio.
a) increases
b) decreases
c) remains same
d) none of the mentioned

View Answer

Answer: b

10. When a smaller number of large cylinders are used, the friction and economy improve.
a) True
b) False

View Answer

Answer: a

11. The frictional mean effective pressure ____________ as the compression ratio is increased.
a) increases
b) decreases
c) remains same
d) none of the mentioned

View Answer

Answer: a