MCQ on IC engine

11-Stoichio metric fuel ratio:
(A) 20:1
(B) 15:1
(C) 12:1
(D) 8:1
[expand title=”View Answer”](B) 15:1[/expand]
12-Which is not the effect of detonation?
(A) high operating temperature
(B) loss in efficiency and power output
(C) loud and pulsating noise
(D) high local stresses
[expand title=”View Answer”](D) high local stresses[/expand]
13-The brake power is 7.5 kw and frictional power is 2.5 kw, then the indicated power is:
(A) 2.5 kw
(B) 5.0 kw
(C) 7.5 kw
(D) 10 kw
[expand title=”View Answer”](D) 10 kw[/expand]
14-Scavenging air means
(A) air sent under compression
(B) air used for forcing the burnt gases out of the cylinder during the exhaust period
(C) forced air for cooling the engine cylinder
(D) burnt air conditioning combustion products
[expand title=”View Answer”](B) air used for forcing the burnt gases out of the cylinder during the exhaust period[/expand]
15-The ignition temperature of diesel is about
(A) 250°C
(B) 400°C
(C) 600°C
(D) 750°C
[expand title=”View Answer”](A) 250°C[/expand]
16-Highest useful compression ratio is the compression ratio at which the engine
(A) gives maximum power output
(B) can operate without detonation
(C) consumes minimum fuel for a particular power output
(D) maintains operating pressure and temperatures within prescribed limits
[expand title=”View Answer”](C) consumes minimum fuel for a particular power output[/expand]
17-In air brake system, compressor is driven by:
(A) Engine itself
(B) Electric motor
(C) Hand operated
(D) Battery
[expand title=”View Answer”](A) Engine itself[/expand]
18-How many number of working stroke per minute will take place for a 1600 rpm single cylinder four stroke engine?
(A) 400
(B) 800
(C) 1600
(D) 3200
[expand title=”View Answer”](B) 800[/expand]
19-Knocking tendency in SI engine reduces with increasing:
(A) Compression ratio
(B) Wall temperature
(C) Engine speed
(D) None
[expand title=”View Answer”](C) Engine speed[/expand]
20-The two reference fuels used for cetane rating are:
(A) Cetane and iso octane
(B) Cetane and tetra ethyl lead
(C) Cetane and alpha methyl naphthalene
(D) None
[expand title=”View Answer”](C) Cetane and alpha methyl naphthalene[/expand]