Heat Engine and Efficiency

All engines operate at less than 100% efficiency because they ___________.

• absorb heat

• conduct heat

• burn gasoline

• emit heat

What is the function of a heat engine?

• It converts chemical energy to mechanical energy.

• It converts thermal energy to mechanical energy

• It converts mechanical energy to chemical energy.

• It converts thermal energy into chemical energy.

What is the correct sequence of four cycle-stroke of gasoline engine?

1. Intake 2. Exhaust 3. Power 4. Compression

• a. 1,2,3,4

• b. 1,4,3,2

• c. 2,3,4,1

• d. 1, 3,4,2

Why is heat engine not 100% efficient?

• All mixture of gases is converted into work.

• Some of the gases is exhausted in the surroundings.

• All of the gases are used up by the engine.

• Some of the gases is taken up in the piston.

Which occurs just before ignition?

• Intake stroke

• Compression stroke

• Exhaust stroke

• Power stoke