Deck 1: Internal Combustion Engines and Their Advantages and Disadvantages

Question 1

Advantage of reciprocating IC engines over steam turbine is

A)Mechanical simplicity
B)Improved plant efficiency
C)Lower average temperature
D)all of the above

Answer 1

all of the above

Question 2

The intake charge in a diesel engine consists of

A)air alone
B)air + lubricating oil
C)air + fuel
D)air + fuel + lubricating oil

Answer 2

air alone

Question 3

Engines of different cylinder dimensions, power and speed can be compared on the basis of

A)Maximum pressure
B)Fuel consumption
C)mean effective pressure
D)unit power

Answer 3

mean effective pressure

Question 4

Disadvantages of reciprocating IC engine are

A)vibration
B)use of fossil fuels
C)balancing problems
D)all of the above

Question 5

Gudgeon pin forms the link between

A)piston and big end of connecting rod
B)piston and small end of connecting rod
C)connecting rod and crank
D)big end and small end

Question 6

In a four-stroke IC engine cam shaft rotates at

A)same speed as crankshaft
B)twice the speed of crankshaft
C)halt the speed of crankshaft
D)none of the above

Question 7

Thermal efficiency of CI engine is higher than that of SI engine due

A)light weight
B)higher compression ratio
C)constant pressure heat addition
D)none of the above

Question 8

SI engines are of

A)light weight
B)high speed
C)homogeneous change of fuel and oil
D)all of the above

Question 9

Compression ratio in diesel engines is of the order of

A)5-7
B)7 -10
C)10 - 12
D)14-20

Question 10

Main advantage of a two-stroke engine over four-stroke engine is

A)more uniform torque on the crankshaft
B)more power output for the cylinder of same dimensions
C)absence of valves
D)all of the above

Question 11

Engines used for ships are normally

A)four-stroke Sl engines of very high power
B)two-stroke CI engines of very high power
C)four-stroke Cl engines of high speed
D)two-stroke SI engines of high power

Question 12

If L is the stroke and N is the rpm, mean piston speed of two-stroke engine

A)LN
B)LN/2
C)2LN
D)none of the above

Question 13

The volumetric efficiency of the SI engine is comparatively

A)lower than CI engine
B)higher than CI engine
C)will be same as CI engine
D)none of the above

Question 14

Brake specific fuel consumption is defined as

A)fuel consumption per hour
B)fuel consumption per km
C)fuel consumption per BP
D)fuel consumption per brake power hour

Question 15

Engine can be fired with

A)solid fuel
B)liquid fuel
C)gaseous fuel
D)any of the above fuels

Question 16

A two-stroke engine can be identified by

A)cooling system
B)lubrication system
C)absence of valves
D)piston size

Question 17

Advantage of two-stroke engine is

A)more uniform torque
B)lighter flywheel
C)no valves
D)all of the above

Question 18

Charge pressure at the inlet port of a two-stroke engine is

A)20 bar
B)vacuum
C)atmospheric
D)higher than atmospheric

Question 19

The most perfect method of scavenging is

A)cross scavenging
B)uniflow scavenging
C)loop scavenging
D)reverse flow scavenging

Question 20

Two-stroke SI engines suffer from

A)fuel loss
B)idling difficulty
C)both (a) and (b) together
D)none of the above

Question 21

At the same speed two-stroke engine of the same size as a four-stroke engine will develop

A)same power
B)half the power
C)twice the power
D)four times the power

Question 22

Two wheelers without deflector type piston use

A)loop scavenging
B)unifow scavenging
C)reverse flow scavenging
D)cross scavenging

Question 23

Crankcase scavenged engines have delivery ratio of

A)greater than 1
B)less than 1
C)equal to 1
D)none of the above

Question 24

The working cycle in case of four stroke engine is completed in following number of revolutions of crankshaft

A)1/2
B)1
C)2
D)4

Question 25

In a diesel engine, the fuel is ignited by

A)spark
B)injected fuel
C)heat resulting from compressing air that is supplied for combustion
D)ignitor