ic engines objective questions with answers part5

Q1. "The knock in diesel engine occurs due to"
(A) " instantaneous and rapid burning of the first part of the charge"
(B) " instantaneous atuo iginition of last part of charge"
(C) " delayed burning of the first part of the charge"
(D) " reduction of delay period"

Q2. Polymerisation is a chemical process in which molecules of a compound become
(A) larger
(B) slow down
(C) smaller
(D) liquid

Q3. The term scavenging is generally associated with
(A) 2-stroke cycle engines
(B) 4-stroke cycle engines
(C) diesel engines
(D) high efficiency engines

Q4. In diesel engine, the compression ratio in comparison to expansion ratio is
(A) same
(B) less
(C) more
(D) variable

Q5. The cam shaft of a four stroke I.C. engine running at 1500 rmp will run at
(A) 1500 rpm
(B) 750 rpm
(C) 3000 rpm
(D) any value independent of engine speed

Q6. Engine pistons ‘are usually made of aluminium alloy because it
(A) is lighter
(B) wears less
(C) absorbs shocks
(D) is stronger

Q7. Most high speed compression engines operate on
(A) Otto cycle
(B) Diesel cycle
(C) Dual cycle
(D) Carnot cycle

Q8. 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

Q9. A diesel engine as compared to petrol engine (both running at rated load) is
(A) more efficient
(B) less efficient
(C) equally efficient
(D) some other factors decide it

Q10. 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

Q11. In a cycle, the spark lasts roughly for
(A) 1.2 sec
(B) 0.1 sec
(C) 0.01 sec
(D) 0.001 sec

Q12. Which of the following is false statement :Excess quantities of sulphur in diesel fuel are Objectionable because it may cause the following
(A) piston ring and cylinder wear
(B) formation of hard coating on piston skirts
(C) oil sludge in the engine crank case
(D) detonation

Q13. of the following is false statement. Some of the methods used to reduce diesel smoke are as follows
(A) using additives in the fuel
(B) reducing the maxi-mum flow of fuel
(C) increasing the compression ratio
(D) adherence to proper fuel specification

Q14. 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

Q15. Pick up the wrong statement about supercharging
(A) supercharging reduces knocking in diesel engines
(B) there can be limited supercharging in petrol engines because of detonation
(C) supercharging at high altitudes is essential
(D) supercharging results in fuel economy

Q16. The actual volume of fresh charge admitted in 4-stroke petrol engine is
(A) equal to stroke volume
(B) equal to stroke volume and clearance volume
(C) less than stroke volume
(D) more than stroke volume

Q17. The magneto in an automobile is basically
(A) transformer
(B) d.c. generator
(C) magnetic circuit
(D) a.c. generator.

Q18. The reason for supercharging in any engine is to
(A) increase efficiency
(B) increase power
(C) reduce weight and bulk for a given out-put
(D) effect fuel economy

Q19. The operation of forcing additional air under pressure in the engine cylinder is known as
(A) scavenging
(B) turbulence
(C) supercharging
(D) pre-ignition

Q20. Supercharging is essential in
(A) diesel engines
(B) gas turbines
(C) petrol engines
(D) aircraft engines