Elevator Mechanic Practice Exam

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Prepare for the Elevator Mechanic Exam with comprehensive quizzes, flashcards, and multiple-choice questions. Each question includes hints and detailed explanations to ensure you are ready for your exam!

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A contractor wants to raise the car speed from 100fpm to 125fpm, it currently has a 12" sheave. What sheave is required?

10" sheave
15" sheave
20" sheave
18" sheave

The correct answer is: 10" sheave

To determine the required sheave size for raising the car speed from 100 feet per minute (fpm) to 125 fpm using a specific formula, we can use the relationship between speed and the diameter of the sheave. The car speed is inversely proportional to the diameter of the sheave; therefore, to increase the car speed while maintaining the same motor RPM, you need to use a smaller sheave. Given that the current sheave is 12 inches and the speed needs to increase, using a smaller sheave will effectively increase the speed. In this case, choosing a 10-inch sheave reduces the circumference and allows the elevator car to move faster, achieving the desired speed increase from 100 fpm to 125 fpm. The other options, which involve larger sheaves, would decrease the speed further, making them unsuitable for achieving the target speed increase. Thus, selecting a 10-inch sheave is the correct choice to meet the new specifications.