Question

In $R-C$ circuit $\omega =100rad{s}^{-1},R=100\Omega ,C=20\mu F$. What is impedance?

• A. $510\Omega$
• B. $200\Omega$
• C. $250\Omega$
• D. $300\Omega$

Answer 1

Answer: (A)

Impedance for an R-C circuit is given by
$Z=\sqrt{R^2+X_C^2}=\sqrt{R^2+{\left(\frac{1}{\omega C}\right)}^2}$
$=\sqrt{(100{)}^2+{\left(\frac{1}{100\times 20\times 10^{-6}}\right)}^2}$
$=\sqrt{10^4+25\times 10^4}$
$=100\sqrt{26}$
$=510\Omega$