28. technician a says that during one four-stroke cycle of a cylinder, the crankshaft completes
one revolution. technician b says that during one four-stroke cycle of a cylinder, the camshaft
completes one revolution. who is wrong? explain why?

Technician A is wrong

Explanation:
During the intake stroke and compression stroke, the piston goes up and down once as it takes in the air and compressed it. The crank then makes another turn as the compressed fuel air mixture is combusted and the piston is forced down, then back up again through the exhaust valve. This makes the crankshaft complete more then one full revolution. The camshaft however is different. It takes a full turn when it opens the intake valve, closes it, opens the exhaust valve, closes it, and then comes back around again to complete the cycle. Each cycle takes one rotation of the camshaft due to the fact that the camshaft opens the valves. However, more then one full turn for the crankshaft as the piston has to go up and down a couple times in between this cycle. Thus, technician A is wrong.

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