Home Physics Alternating Current (AC)

Alternating Current (AC)

Alternating currents, peak and RMS value of alternating current/voltage; reactance and impedance; LC oscillations (qualitative treatment only), LCR series circuit, resonance; power in AC circuits, power factor, wattless current. AC generator and transformer.

12th physics. NCERT notes

AC Generator

AC Generator: AC generator is the one which produces a current that alternates or changes its direction regularly after a fixed interval of time, i.e.,...
12th physics. NCERT notes

Transformer

A transformer is an electrical device used for converting low alternating voltage into a high alternating voltage and vice versa. It transfers electric power...
12th physics. NCERT notes

Wattless Current

The current in a.c. circuit is said to be wattles if the average power consumed in the circuit is zero. The average power of an...
12th physics. NCERT notes

Power in an AC Circuit

In an AC circuit, the current and emf vary continuously with time. Therefore power at a given instant of time is calculated and then its mean...
12th physics. NCERT notes

Resonance

Series resonance or voltage resonance in RLC circuit: The value of current at any instant in a series RLC circuit is given by At a particular...
12th physics. NCERT notes

LCR Series Circuit

Let an alternating source of emf e be connected to a series combination of a resistor of resistance R, an inductor of inductance L...
12th physics. NCERT notes

LC Oscillations

When a charged capacitor is allowed to discharge through a non-resistance, electrical oscillations of constant amplitude and frequency are produced. These oscillations are called...
12th physics. NCERT notes

Representation of AC Current and Voltage by Rotating Vectors

Representation of AC Current and Voltage by Rotating Vectors The analysis of an ac circuit is by using a phasor diagram. A phasor is a...
12th physics. NCERT notes

Reactance

An ac voltage v = vm sinωt applied to a pure inductor L, drives a current in the inductor i = im sin(ωt...
12th physics. NCERT notes

Alternating current (AC) & Alternating Voltage

Alternating current (AC) An alternating current is one whose magnitude changes sinusoidally with time. Thus alternating current is given by Where i0=current amplitude or peak value...