Question

A $50\,Hz\,AC$ signal is applied in a circuit of inductance of $(1/\pi )H$ and resistance $2100\,\Omega$ The impedance offered by the circuit is

• A. $1500\,\Omega$
• B. $1700\,\Omega$
• C. $2102\,\Omega$
• D. $2500\,\Omega$

Answer 1

Answer: (C)

$2102\,\Omega$

Answer 2

Impedance $Z=\sqrt{R^{2}+X_{L}^{2}} X_{L}=\omega L=2 \pi f L$
Given. $R=2100 \Omega, f=50\, Hz,\, L=\frac{1}{\pi}$
$Z=\sqrt{(2100)^{2}+(2 \times 50)^{2}}$
$=\sqrt{(2100)^{2}+(100)^{2}}$
$Z=2102\, \Omega$