What is the average current drawn by a 1.0-hp 120-V motor? (1 hp = 746 W.)

Verified step by step guidance

1. Convert the horsepower (hp) rating of the motor to watts (W) using the conversion factor: 1 hp = 746 W. Multiply 1.0 hp by 746 W/hp to find the power in watts.
2. Recall the formula for electric power: $P=VI$, where $P$ is power, $V$ is voltage, and $I$ is current. Rearrange the formula to solve for current: $I=P/V$.
3. Substitute the power in watts (calculated in step 1) and the voltage (120 V) into the formula $I=P/V$.
4. Perform the division to calculate the current in amperes (A). This will give the average current drawn by the motor.
5. Ensure the units are consistent throughout the calculation and verify the result to confirm it is reasonable for a motor of this size.

Key Concepts

Power

Power is the rate at which energy is transferred or converted. In electrical systems, power (P) is calculated using the formula P = VI, where V is voltage and I is current. In this context, the motor's power rating of 1.0 horsepower (hp) can be converted to watts, as 1 hp equals 746 watts.

Voltage

Voltage, or electric potential difference, is the force that pushes electric charges through a circuit. It is measured in volts (V). In this question, the motor operates at a voltage of 120 V, which is essential for determining the current drawn by the motor when it is running at its rated power.

Current

Current is the flow of electric charge in a circuit, measured in amperes (A). It can be calculated using the formula I = P/V, where P is power in watts and V is voltage. By knowing the power rating of the motor and the voltage it operates at, we can find the average current drawn by the motor.