Red Seal Heavy Duty Equipment Technician Practice Exam

Which of the following defines the interaction between engine RPM and torque?

1. It determines the engine's lifecycle

2. It calculates the engine's horsepower

3. It measures the engine's wear and tear

4. It controls the engine's cooling system

The correct answer is: It calculates the engine's horsepower

The interaction between engine RPM (revolutions per minute) and torque is fundamentally tied to calculating the engine's horsepower. Horsepower is a measurement that represents the engine's power output, which depends on both the torque produced by the engine and its RPM. The relationship is described by the formula: Horsepower = (Torque × RPM) / 5252. This equation highlights that higher RPMs with a certain level of torque will produce more horsepower and vice versa. Understanding this interaction is critical in assessing an engine's performance characteristics, as it helps determine how effectively an engine can perform work under various conditions. The other options do not accurately capture this relationship. Defining an engine's lifecycle relates more to its overall use and maintenance rather than the direct interaction of RPM and torque. Measuring engine wear and tear involves various diagnostics and assessments, while controlling the engine's cooling system is primarily concerned with temperature regulation, rather than power output.