Question

An inductor of inductance l and resistor of resistance r are joined in series and connected by source of frequency power dissipated in the circuit is

Answer 1

The power dissipated in the circuit is $P =(V^{2}R)/(R^{2}+XL^{2})$

1. First  the impedance(Z) of the circuit is
2. $Z=\sqrt{(R^{2} +XL^{2} )}$
3. Current flowing through the circuit is given as
4. I = V/Z
5. $I=V / \sqrt{(R^{2} +XL^{2} )}$
6. The power dissipated in the circuit is $P=I^{2}R$
7. $P = (V / \sqrt{(R^{2} +XL^{2} )})^{2} .R$
8. $P =(V^{2}R)/(R^{2}+XL^{2})$