Question

Which of the following curve correctly represents impedance(Z) with frequency (n) of applied voltage

• A.
• B.
• C.
• D.

Answer 1

The correct option is D

$Z$ is maximum at resonance frequency
$Z^2=R^2+(x_L-X_C{)}^2$
at $X_{c}w=w_0\Rightarrow X_L=X_C$
$\Rightarrow Zmin=R$
$\Rightarrow w_0=\frac{1}{\sqrt{LC}}$
At this value of ${\omega }_0$, we will see lowest value of $Z$. So upon increasing or decreasing $\omega$, we see that value of $Z$ is bound to increase. We can see such type of graph in only one option and that is option (d).