The fuel air ratio in a petrol engine fitted with suction carburettor, operating with dirty air filter as compared to clean filter will be________________?
(A) higher
(B) lower
(C) remain unaffected
(D) unpredictable
(D) none of the above
The size of inlet valve of.an engine in comparison to exhaust valve is_________________?
(A) more
(B) less
(C) same
(D) more/less depending on capacity of engine
(D) varies from design to design
The specific fuel consumption of a petrol engine compared to diesel engine of same H.P. is_______________?
(A) same
(B) more
(C) less
(D) less or more depending on operating conditions
(D) unpredictable
Engine pistons ‘are usually made of aluminium alloy because it_________________?
(A) is lighter
(B) wears less
(C) absorbs shocks
(D) is stronger
(D) does not react with fuel and lub oil
In the crankcase method of scavenging, the air pressure is produced by_________________?
(A) supercharger
(B) centrifugal pump
(C) natural aspirator
(D) movement of engine piston
(D) reciprocating pump
In loop scavenging, the top of the piston is________________?
(A) flat
(B) contoured
(C) slanted
(D) depressed
(D) convex shaped
A stoichiometric air-fuel ratio is______________________?
(A) chemically correct mixture
(B) lean mixture
(C) rich mixture for idling
(D) rich mixture for over loads
(D) the ratio used at full rated parameters
Which is more viscous lub oil_________________?
(A) SEA 30
(B) SAE 4£
(C) SAE 50
(D) SAE 70
(D) SAE 80
The air-fuel ratio in petrol engines-is controlled by__________________?
(A) controlling valve opening/closing
(B) governing
(C) injection
(D) carburettion
(D) scavenging and supercharging
Pour point of fuel oil is the_________________?
(A) minimum temperature to which oil is heated in order to give off inflammable vapours in sufficient quantity to ignite momentarily when brought in contact with a flame
(B) temperature at which it solidifies or congeals
(C) it catches fire without external aid
(D) indicated by 90% distillation temperature i.e., when 90% of sample oil has distilled off
(D) temperature at which it flows easily