Measurement of Electrical Power
Measure electric power with an ammeter and a voltmeter.
Electric power in a circuit can be measured with an ammeter (amperemeter) and a voltmeter.
The power can be calculated as
P = U I
= R I2 (1)
where
P = electric power (W, watts)
U = voltage (V, volt)
I = current (A, ampere)
R = resistance (Ω, ohm)
Example - Power consumption of a circuit with an electric heater
The current in a 230 V household circuit with an electric heater is measured with an ammeter to 8 A. The power consumption can be calculated as
P = (230 V) (8 A)
= 1840 W
