Internal Combustion Engines – Questions and Answers
1- In four stroke engine, one working cycle is completed by ___ revolutions of crankshaft
(A) 1
(B) 2
(C) 3
(D) 4
2- In diesel, scavenging means
(A) removal of combustion products from an internal combustion engine cylinder on the return stroke of the piston
(B) air induced in the cylinder during intake stroke
(C) air used for cooling of cylinder
(D) none of the above
3- Indicated thermal efficiency / corresponding air standard cycle efficiency =
(A) volumetric efficiency
(B) overall efficiency
(C) relative efficiency
(D) none of the above
4- The efficiency of an Internal Combustion Engine ___ if the intake air temperature increases.
(A) decreases
(B) increases
(C) remains same
(D) first decreases then increases
5- The function of engine indicator is to measure
(A) speed of engine
(B) mean effective pressure (mep) and Indicated Horse Power (IHP)
(C) Break Horse Power (BHP)
(D) temperature of engine
6- The combustion in spark ignition engine is
(A) homogeneous
(B) heterogeneous
(C) both (A) and (B)
(D) none of the above
7- Which of the following is (are) Internal Combustion Engine(s)?
(A) petrol engine
(B) diesel engine
(C) gas turbine
(D) all of the above
8- Following device in used in petrol engine to control air-fuel ratio.
(A) fuel pump
(B) governor
(C) valve
(D) carburetor
9- Engine pistons are generally made of
(A) copper alloy
(B) tin alloy
(C) aluminium alloy
(D) iron alloy
10- Which of the following increases power output of engine?
(A) supercharger
(B) cold air intake
(C) scavenging
(D) all of the above
11- The diesel engine usually has ___ valves.
(A) two
(B) three
(C) four
(D) six
12- Following is the most viscous lubricating oil
(A) SAE 20
(B) SAE 30
(C) SAE 40
(D) SAE 50
13- Iso-octane has octane number of ___ .
(A) 0
(B) 50
(C) 80
(D) 100
14- The piston ring nearer to the piston crown is known as
(A) pressure ring
(B) lubrication ring
(C) top ring
(D) compression ring
15- Detonation can be controlled by
(A) retarding the spark timing
(B) varying compression ratio
(C) using lean mixture
(D) all of the above
16- In diesel engine, mixing of fuel and air occurs in
(A) fuel pump
(B) engine cylinder
(C) carburetor
(D) injector
17- The function of fins on engine of motor cycle is to
(A) cool the engine
(B) make good appearance
(C) provide strength to engine
(D) balance the engine
18- A two stroke crank compressed has ___ port.
(A) inlet
(B) transfer
(C) exhaust
(D) all of the above
19- The specific gravity of petrol at 60°F (15.55°C) is about
(A) 0.62
(B) 0.74
(C) 0.81
(D) 0.93
20- Following is the lightest and most volatile liquid fuel
(A) petrol
(B) diesel
(C) kerosene
(D) none of the above
ANSWERS:
1-(B), 2-(A), 3-(C), 4-(A), 5-(B), 6-(A), 7-(D), 8-(D), 9-(C), 10-(D), 11-(C), 12-(D), 13-(D), 14-(D), 15-(A), 16-(B), 17-(A), 18-(D), 19-(B), 20-(A)