Embibe Experts Solutions for Chapter: Alternating Current, Exercise 1: assam board-2018

How are eddy currents are minimised in a transformer.

So that average power dissipated by a pure inductor and a pure capacitor is zero when they are connected to an a.c. voltage source.

The amplitude of the current in series LCR circuit connected to an AC frequency $"\omega "$is given by,

${\mathrm{i}}_{\mathrm{m}}=\frac{{\mathrm{v}}_{\mathrm{m}}}{\sqrt{{\mathrm{R}}^2+{\left({\mathrm{X}}_{\mathrm{L}}-{\mathrm{X}}_{\mathrm{C}}\right)}^2}}$.

Where ${\mathrm{X}}_{\mathrm{L}} \mathrm{and} {\mathrm{X}}_{\mathrm{C}}$ are inductive and capacitive reactants respectively and $"{\mathrm{v}}_{\mathrm{m}}"$ is the amplitude of the voltage. Starting from this equation show that the sharpness of resonance the circuit is equal to the quality factorof the circuit.

A source of emf, ${\mathrm{V}}_{{\mathrm{m}}_{}}\sin \mathrm{\omega t}$ is connected in series with an inductor $\mathrm{L}$, capicitor $\mathrm{C}$ . and resistor $\mathrm{R}$. Calculate the impedance and resonance frequency of the circuit. Also, write the application of the resonant circuit.