What is the approximate efficiency of a motor with an output of 2 hp and an input of 2487 watts (1 hp equals 746 watts)?

To determine the efficiency of the motor, you first need to convert the output power from horsepower (hp) to watts. Given that 1 horsepower equals 746 watts, for a motor with an output of 2 hp, the output in watts is calculated as:

2 hp * 746 watts/hp = 1492 watts.

Efficiency is defined as the ratio of output power to input power, expressed as a percentage. The formula for efficiency can be represented as:

Efficiency (%) = (Output Power / Input Power) × 100.

Substituting the values you've calculated:

Efficiency (%) = (1492 watts / 2487 watts) × 100.

Now performing the calculation:

Efficiency (%) ≈ (0.5992) × 100 ≈ 59.92%.

When rounded to the nearest whole number, this yields an efficiency of approximately 60%.

This value matches with one of the choices, confirming that the efficiency of the motor is around 60%, which aligns with option B. Understanding the calculation of efficiency helps clarify how effectively a motor converts input energy into useful work.