Question

technician a says that the compression stroke is also called the expansion stroke. technician b says that the compression ratio compares the cylinder volume at bdc to tdc. who is correct?

a. technician a

b. technician b

c. both technician a and technician b

d. neither technician a nor technician b

Explanation:

• For Technician A: The compression stroke and expansion (power) stroke are distinct in an engine cycle. Compression stroke compresses the air - fuel mixture, while expansion stroke is where power is produced. So Technician A is wrong.
• For Technician B: The compression ratio is defined as the ratio of the cylinder volume at Bottom Dead Center (BDC, maximum volume) to the volume at Top Dead Center (TDC, minimum volume). So Technician B is correct.

Answer:

b. Technician B