Question

question 6 of 10
which of the following sequences describes how a four-stroke engine cycle powers the engine?

a. contraction, compression and ignition, air and fuel intake, exhaust

b. air and fuel intake, compression and ignition, combustion and expansion, exhaust

c. expansion, air and fuel intake, compression and ignition, extinguishment

d. hydrogen and fuel intake, expansion, compression and ignition, exhaust

Explanation:

A four - stroke engine cycle has four distinct strokes. The first stroke is the intake stroke where air and fuel are taken into the cylinder. The second stroke is the compression stroke where the air - fuel mixture is compressed, and then ignition occurs. The third stroke is the power (combustion and expansion) stroke where the combustion of the air - fuel mixture causes expansion and generates power. The fourth stroke is the exhaust stroke where the exhaust gases are expelled.

• Option A has an incorrect order as contraction is not a part of the four - stroke cycle and the intake is out of place.
• Option C has incorrect processes like expansion being first and extinguishment which is not a part of the cycle.
• Option D has incorrect intake (hydrogen is not the typical intake for a standard four - stroke engine) and incorrect order of processes.
• Option B follows the correct sequence of air and fuel intake, compression and ignition, combustion and expansion, and exhaust.

Answer:

B. Air and fuel intake, compression and ignition, combustion and expansion, exhaust