Question

An alternating supply of $220\,V$ is applied across a circuit with resistance $22\,\Omega$ and impedance $44\,\Omega$. The power dissipated in the circuit is

• A. $1100\,W$
• B. $550\,W$
• C. $2200\,W$
• D. $(2200/3)\,W$

Answer 1

Answer: (B)

$550\,W$

Answer 2

Here, $V= 220\,V$ Resistance, $R = 22\,\Omega$ Impedance, $Z = 44\,\Omega$ Current in circuit, $I=\frac{V}{Z}$ $=\frac{220\,V}{44\,\Omega}$ $= 5\,A$ Power dissipated in the circuit, $P=I^{2}R=\left(5\right)^{2}\times22$ $=550\,W$