If a furnace blower motor measures 10 R ohms and draws 5 amps on a 120 volt source, what is the impedance?

To determine the impedance of the furnace blower motor, you can use the relationship between voltage, current, and impedance in alternating current (AC) circuits.

The formula for impedance (Z) in a circuit is given by:

[ Z = \frac{V}{I} ]

where:

• ( V ) is the voltage (in volts)

• ( I ) is the current (in amps)

In this scenario, the motor operates at a voltage of 120 volts and draws a current of 5 amps. Applying the values to the formula results in:

[ Z = \frac{120 \text{ volts}}{5 \text{ amps}} = 24 \text{ ohms} ]

Thus, the impedance of the furnace blower motor is correctly calculated as 24 ohms, which accurately corresponds to the choice provided.

The other choices (10, 20, and 30 ohms) do not align with this calculation, as they do not reflect the relationship established by the voltage and current involved with this motor under normal operating conditions. This calculation effectively combines the resistive and reactive aspects of the motor's operation, leading to the final result of 24 ohms as the total impedance.