Four-Stroke Engine Quiz

What occurs during the intake stroke of a four-stroke engine?

• The piston moves upward, compressing the air-fuel mixture.

• The exhaust valve opens to release gases.

• The intake valve opens, allowing air and fuel to enter the cylinder.

• The spark plug ignites the fuel mixture.

During which stroke is the air-fuel mixture compressed in a four-stroke engine?

• Intake stroke

• Compression stroke

• Power stroke

• Exhaust stroke

What happens at the start of the power stroke in a four-stroke engine?

• The intake valve opens, allowing air into the cylinder.

• The spark plug ignites the compressed fuel-air mixture.

• The piston moves downward to exhaust gases.

• The piston compresses the fuel mixture further.

What is the main purpose of the exhaust stroke in a four-stroke engine?

• To allow fuel to enter the combustion chamber.

• To compress the fuel and air mixture.

• To expel the burnt gases from the cylinder.

• To ignite the fuel-air mixture.

How does the piston move during the intake stroke?

• It moves upward to compress the fuel-air mixture.

• It moves downward, creating a vacuum that pulls air and fuel into the cylinder.

• It remains stationary while valves open and close.

• It moves upward to push exhaust gases out of the cylinder.

During the compression stroke, how much does the fuel-air mixture get compressed?

• It doubles in size.

• It is compressed about 8.5 times its original size.

• It is compressed 4 times its original size.

• It stays the same size as when it entered the cylinder.

What happens during the power stroke of a four-stroke engine?

• The intake valve opens to let fuel in.

• The fuel-air mixture ignites, creating pressure that pushes the piston down.

• The exhaust valve opens to release gases.

• The spark plug ignites the mixture, but the piston remains stationary.

What is valve overlap, and when does it occur in a four-stroke engine?

• It’s when the intake and exhaust valves are open at the same time, happening at the end of the exhaust stroke.

• It’s when the exhaust valve stays open longer than necessary.

• It’s when the intake valve is open for too long, causing a vacuum in the combustion chamber.

• It happens during the compression stroke to enhance power generation.

Which stroke completes the exhaust cycle in a four-stroke engine?

• Intake stroke

• Compression stroke

• Power stroke

• Exhaust stroke

Why is the compression stroke important in a four-stroke engine?

• It allows air to enter the cylinder at the correct pressure.

• It ignites the fuel-air mixture.

• It increases the pressure and temperature of the fuel-air mixture for efficient combustion.

• It expels spent gases from the cylinder.