Question

In most four-stroke internal combustion engines, when does the piston move upward?

A. during the compression stroke only

B. during the compression and exhaust strokes

C. during the intake and exhaust strokes

D. during the power and intake strokes

Answer 1

B

The compression stroke is needed to get the mix of gasoline and air to ignite.

The exhaust stroke is needed to push the exhaust gases out of the cylinder before the next intake stroke.

Answer 2

C. during the intake and exhaust strokes

Step-by-step explanation:

In four stroke engine one complete cycle of gas is completed in four strokes

Two compression strokes

Two expansion strokes

In first expansion stroke the engine will intake air and mix it into the fuel

while in its other expansion stroke it will exhaust all the burnt gases from the engine.

so here in this four stroke engine when piston moves up then due to expansion piston moves up and correct answer for it is

C. during the intake and exhaust strokes