Ac voltage

Definition

AC voltage is a type of electrical current where the voltage periodically changes direction. It is commonly used in household power supplies and electrical grids due to its efficiency in long-distance transmission.

5 Must Know Facts For Your Next Test

1. AC voltage alternates between positive and negative values, typically in a sinusoidal wave form.
2. The frequency of AC voltage in most countries is either 50 Hz or 60 Hz.
3. Root Mean Square (RMS) value of AC voltage is used to represent its effective value, which corresponds to the equivalent DC voltage that delivers the same power.
4. Impedance, rather than simple resistance, affects how AC voltage interacts with circuit elements like resistors, capacitors, and inductors.
5. Phasor diagrams are often used to analyze AC circuits by representing voltages and currents as rotating vectors.

Review Questions

• What is the typical waveform shape of AC voltage?
• How does impedance affect an AC circuit differently compared to resistance?
• What does the RMS value of an AC voltage represent?

Related terms

Frequency:

The number of cycles per second in an alternating current, measured in Hertz (Hz).

Impedance:

A measure of opposition to AC current flow in a circuit, combining resistance and reactance.

Phasor Diagram:

A graphical representation of the magnitude and phase angle of sinusoidal functions related to AC circuits.