Motor Diesel Soal Jawab ATT-II

Computer Based Assessment (CBA) Motor Diesel 

1). Which is false statement about advantages of V-type engine
a. Compact design requiring lesser space.
b. Improved distribution of air to cylinder.to distortion.
c. Casting less liable to distortion
d. Reduced torsion vibration because of shorter crankshaft ✔️
e. Less overhead clearance.

2). The pistons are usually given a coating such as tin plating in order to
a. Reduce weight.
b. Conduct heat efficiently ✔️
c. Reduce possibility of scoring
d. Reduce friction.
e. Increase lubrication effect.

3). Piston rings are usually made of.
a. Cast iron
b. Aluminium ✔️
c. Phosphor bronze.
d. Babbitt.
e. Carbon steel.

4). Piston rings are plated with chromium , cadmium or phosphate in order to.
a. Reduce cost.
b. Improve surface finish
c. Prevent clogging.
d. Reduce wear and eliminate scuffing.
e. Improve heat transfer. ✔️

5). The top piston ring nearer to the piston crown is known as.
a. Compression ring .
b. Oil ring.
c. Scrapper ring.
d. Groove ring.
e. Leading ring. ✔️

6). In order to prevent knock in the S.I engines .the charge away from the spark plug should have .
a. Low temperature.
b. Low density.
c. Long Ignition delay.
d. Rich mixture. ✔️
e. All of the above.

7). Diesel engines have low specific fuel consumtion compared to petrol engine .This statement is.
a. Not true. ✔️
b. True at full load.
c. True at part load.
d. True at both part and full load.
e. There could not be any such criterion.

8). To reduce the possibility of knock in the C.I engines ,the first elements of fuel and air should have.
a. High temperature.
b. High density.
c. Short delay.
d. Reactive mixture.
e. All of the above. ✔️

9). The detonation tendency  in petrol engine for specified condition of fuel rating, compression ratio, speed etc.Can be con-trolled by having.
a. Smaller cylinder bore.
b. Bigger cylinder bore.
c. Medium cylinder bore.
d. Cylinder bore could be anything as it does not control detonation.
e. Proper stroke legth. ✔️

10). According to Recardo^s theory,detonation occurs due to.
a. Instantaneous auto-ignition of last part of charge to be burnt.
b. Impproper mixing of air and fuel. ✔️
c. Improper combustion .
d. Self ignition temperature has nothing to do with detonation.
e. None of the above.

11). A fuel will detonate less if it has.
a. Higher self ignition temperature.
b. Lower self ignition terperature.
c. Improper combustion. ✔️
d. Self ignition temperature has nothing to do with detonation
e. None of the above.

12). The knocking in diesel engines for given fuel,will be.
a. Enhanced by increasing compression ratio.
b. Enhanced by decreasing compression ratio.
c. Unaffected by compression ratio.
d. First enhanced by increasing compression ratio up to a limit beyond which it will be suppressed. ✔️
e. Depeendent on other factors

13). The ignition of charge by some hot surface in the engine cylinder before operation of spark plug is known as.
a. Auto ignition. ✔️
b. Pre. Ignition
c. Retarded ignition.
d. Accelerated ignition
e. Detonation.

14). Injection lag is.
a. The time taken by fuel after injection (before top dead center) to reach upto auto ignition temperature. ✔️
b. Time before actual fuel injection and the pump plugged starts to pump fuel.
c. Time corresponding to actual injection and top dead center.
d. Time corresponding to actual ignition and top dead center.
e. None of the above.

15). Ignition quality of diesel –fuel oil is expressed by an index called.
a. Octane number.
b. Cetane number.
c. Calorific value.
d. Carbon content.
e. Ignition temperature. ✔️