Rms current

Definition

RMS current (I_{rms}) is the root mean square of the alternating current, representing the equivalent direct current value that delivers the same power to a resistor. It is calculated as $I_{rms} = I_0 / \sqrt{2}$ for a sinusoidal AC source, where $I_0$ is the peak current.

5 Must Know Facts For Your Next Test

1. RMS current provides a measure of the effective value of an alternating current.
2. In a purely resistive circuit, RMS current and RMS voltage are in phase with each other.
3. The formula for RMS current in a sinusoidal AC circuit is $I_{rms} = I_0 / \sqrt{2}$.
4. Power calculations in AC circuits often use RMS values because they represent average power over time.
5. RMS values are essential for ensuring that electrical devices can handle the supplied power without overheating.

Review Questions

• What does RMS stand for and why is it important in AC circuits?
• How do you calculate RMS current from peak current in a sinusoidal AC circuit?
• Why are RMS values used when calculating power in AC circuits?

Related terms

Peak Current: $I_0$, the maximum instantaneous value of an alternating current.

RMS Voltage: $V_{rms}$, the root mean square of an alternating voltage, representing its effective value.

Power Factor: A dimensionless number between -1 and 1 that represents the phase difference between voltage and current in an AC circuit.