80°C
120°C
180°C
240°C
C. 180°C
The friction is high
The friction is unpredictable
The small difference in cooling water temperature or in internal friction has a disproportionate effect
The engine is rarely operated
30 to 40 %
40 to 60 %
60 to 70 %
75 to 90 %
ηm = B.P/I.P
ηm = I.P/B.P
ηm = (B.P × I.P)/100
None of these
Otto cycle is more efficient than the Diesel
Diesel cycle is more efficient than Otto
Both Otto and Diesel cycles are, equally efficient
Compression ratio has nothing to do with efficiency
Requires smaller foundation
Is lighter
Consumes less lubricating oil
All of these
More
Less
Same
More/less depending on capacity of engine
Low heat value of oil
High heat value of oil
Net calorific value of oil
Calorific value of fuel
Fuel pump
Fuel injector
Spark plug
None of these
Low
Very low
High
Very high
B.P = (Wl × 2πN)/60 watts
B.P = [(W - S) πDN]/60 watts
B.P = [(W - S) π (D + d) N]/60 watts
All of these
SEA 30
SAE 50
SAE 70
SAE 80
Increase
Decrease
Remain same
None of these
Chemically correct air-fuel ratio by weight
Chemically correct air-fuel ratio by volume
Actual air-fuel ratio for maximum efficiency
None of the above
Enhanced by decreasing compression ratio
Enhanced by increasing compression ratio
Dependent on other factors
None of the above
20 to 40
40 to 60
60 to 80
80 to 100
1 - rγ - 1
1 + rγ - 1
1 - (1/rγ - 1)
None of these
Same
More
Less
Less or more depending on operating conditions
Beginning of suction stroke
End of suction stroke
Beginning of exhaust stroke
End of exhaust stroke
Feeding more fuel
Heating incoming air
Scavenging
Supercharging
0.001 second
0.002 second
0.003 second
0.004 second
Increase
Decrease
Remain same
Increase up to certain limit and then decrease
14.6 : 1
18.5 : 1
20.4 : 1
22.6 : 1
10 bar
20 bar
25 bar
35 bar
Opens at 30° before bottom dead centre and closes at 10° after top dead centre
Opens at 30° after bottom dead centre and closes at 10° before top dead centre
Opens at bottom dead centre and closes at top dead centre
May open and close anywhere
Equally efficient
Less efficient
More efficient
None of these
Low power will be produced
Efficiency will be low
Higher knocking will occur
Black smoke will be produced
0
50
100
120
Benzene
Iso-octane
Normal heptane
Alcohol
Single cylinder petrol engine
Four stroke engine
Single cylinder diesel engine
Multi cylinder engine
High heat value
Low heat value
Net calorific value
Calorific value