Question

In a diesel engine, the fuel is ignited by
(A) Spark
(B) Injected fuel
(C) Heat resulting from compressing air that is supplied for combustion
(D) Ignition

Answer 1

Hint : Combustion starts and temperature reaches to fuel’s ignition temperature. Hence it generally starts with heat resulting from compressing air that supplies for combustion. There is nothing called an ignition system in diesel systems through the output slave.

Complete Step By Step Answer:
In the given question, in a diesel engine the mixture that is fuel vapour and air, mainly consisting of air, is compressed by piston. Piston exerts high pressure and heat is produced.
Basically diesel engine air is compressed to a sufficient high temperature to ignite diesel fuel injected to a cylinder. Piston is actuated by combustion and expansion. They convert the chemical energy into mechanical energy. It operates on a two strokes cycle or four strokes cycle. They gain their energy by burning fuel injected or sprayed into the compressed, hot air charge within the cylinder. The air molecule present should be heated at a temperature greater than the temperature at which the injected fuel can ignite.
Now combustion starts and temperature reaches the fuel's ignition temperature. Hence it generally starts with heat resulting from compressing air that supplies for combustion.
C is the correct answer.

Note :
The fuel is introduced as a piston approaches the center of stroke. A fuel engine does not contain a spark plug.it is completely differ from petrol engine, piston is at bottom dead center. In compression strokes the combo of air and fuel and by the movement of the piston got compressed.