Module 5 Quiz

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

• emit heat

• conduct heat

• absorb heat

• burn gasoline

What is the function of a heat engine?

• It converts mechanical energy to

  chemical energy.

• It converts thermal energy to mechanical energy.

• It converts thermal energy into chemical

  energy.

• It converts chemical energy to

  mechanical energy.

Why is heat engine not 100% efficient?

• All mixture of gases is converted into

  work.

• Some of the gases is taken up in the

  piston.

• Some of the gases is exhausted in the

  surroundings.

• All of the gases are used up by the

  engine.

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

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

• 1,2,3,4

• 1,4,3,2

• 2,3,4,1

• 1, 3,4,2

5. Which occurs just before ignition?

• Power stroke

• Compression stroke

• Exhaust stroke

• Intake stroke

If heat added to the cycle is 40 kJ and the one rejected is 20 kJ,

then the efficiency of the cycle will be

• 40%

• 50% 

• 60%

• 100%