021.10 PISTON ENGINES

Question 1

The camshaft of a piston engine rotates at (the) (same/half/twice) ​the speed of the crankshaft.

Answer 1

The camshaft of a piston engine rotates at (half) the speed of the crankshaft.

Question 2

State which of the following comprises the crank assembly:

• crankcase
• crankshaft
• valve springs
• pistons
• connecting rods

Answer 2

State which of the following comprises the crank assembly:

• crankcase
• crankshaft
• valve springs
• pistons
• connecting rods

Question 3

The power cycle process in a piston engine is (intermittent/continuous) and theoretically the combustion occurs at constant (volume/pressure)​.

Answer 3

The power cycle process in a piston engine is (intermittent) and theoretically the combustion occurs at constant (volume).

Question 4

Ignition occurs in each cylinder of a four-stroke engine (before/behind) TDC at (each/each second) crankshaft revolution.

Answer 4

Ignition occurs in each cylinder of a four-stroke engine (before) TDC at (each second) crankshaft revolution.

Question 5

Diesel engine have a (lower/higher) compresssion ratio and produce (less/more) maximum power as compared to petrol engines.

Answer 5

Diesel engine have a (higher) compresssion ratio and produce (less) maximum power as compared to petrol engines.

Question 6

The higher the compresion ratio, the (lower/higher) the octane rating required.

Answer 6

The higher the compresion ratio, the (higher) the octane rating required.

Question 7

A (thermocouple/bimetallic strip/bourdon tube) is used to monitor the cylinder head temperature.

Answer 7

A (thermocouple) is used to monitor the cylinder head temperature.

Question 8

For a piston engine, the chemically correct fuel/air ration is 1:(…)​.

Answer 8

For a piston engine, the chemically correct fuel/air ration is 1:(15).

Question 9

The richness of a fuel/air mixture ratio is the (mass/volume) of fuel to the (mass/volume) ​of the air.

Answer 9

The richness of a fuel/air mixture ratio is the (mass) of fuel to the (mass) of the air.

Question 10

Concerning the twisting force acting on a propeller blade, the centrifugal twisting force tends to (increase/decrease) the blade angle and the aerodynamic twisting force tends to (increase/decrease) the blade angle.

Answer 10

Concerning the twisting force acting on a propeller blade, the centrifugal twisting force tends to (decrease) the blade angle and the aerodynamic twisting force tends to (increase) ​the blade angle.