Question

In a series circuit R = 300 $\Omega$ , L = 0.9 H, C = 2.0 $\mu$F and $\omega$ = 1000 rad/sec. The impendence of the circuit is

• A. $1300\Omega$
• B. $900\Omega$
• C. $500\Omega$
• D. $400\Omega$

Answer 1

The correct option is C $500\Omega$

$=\sqrt{R^2+[X_L-X_c{]}^2}=\sqrt{R^2+{(Lw-\frac{1}{wc})}^2}$
$=\sqrt{{300}^2+{[900-\frac{1}{{10}^3\times 2\times {10}^{-6}}]}^2}$
$=\sqrt{{300}^2+[900-500{]}^2}$
$=\sqrt{{300}^2+{400}^2}$
$=500\Omega$