Heat Rejection

·         The transfer of heat takes place due to difference in temperature and from higher temperature to lower temperature.

Answer: True

·         The hot gases give part of their heat to

Answer: The hot gases give part of their heat to
a) cylinder liner
b) piston and piston rings
c) cylinder head
d) exhaust valves and exhaust ports

·         Most of the heat is carried away by the cooling system while some is lost by direct radiation from the engine surfaces.

Answer: True

·         At the end of induction stroke the temperature is that of clearance gases.

Answer: No, but in fact, at the beginning of induction stroke the temperature is that of clearance gases.

·         As the cool mixture is inducted in the engine cylinder the temperature rises rapidly.

Answer: Actually, as the cool mixture is inducted in the engine cylinder the temperature falls rapidly.

·         During compression process the temperature ____________ and attains its maximum value at the end of combustion process.

Answer: During compression process the temperature increases and attains its maximum value at the end of combustion process while during the expansion process the temperature decreases and then drops very rapidly during the release process.

·         During the expansion process the temperature ____________ and then drops very rapidly during the release process.

Answer: During the expansion process the temperature decreases and then drops very rapidly during the release process while during compression process the temperature increases and attains its maximum value at the end of combustion process.

·         Inadequate lubrication of the engine, due to oil not being warm enough to flow freely, results in greater frictional losses.

Answer: True

·         A hot-spot outside the combustion chamber may be sufficient to cause pre-ignition.

Answer: In fact, a hot-spot inside the combustion chamber may be sufficient to cause pre-ignition.

·         If the engine is overcooled some of the heat which could be used to expand the gases will be lost.

Answer: True