Question

Given below is the curve between maximum value of current $\left(i_m\right)$ and angular frequency $\left(\omega \right)$ for three different series LCR circuits at same voltage. For which curve, the value of resistance of the resistor is maximum?

• A. Curve - $1$
• B. Curve - $2$
• C. Curve - $3$
• D. All the curve have equal value of resistance of the resistor.

Answer 1

The correct option is A Curve - $1$


We know that, at resonance, $Z=R$.

Also, $i_m=\frac{V_m}{Z}=\frac{V_m}{R}$

At the same voltage, $i_m\propto \frac{1}{R}$

From figure,

$i_{m3}>i_{m2}>i_{m1}\Rightarrow R_1>R_2>R_3$

Hence, option $\left(A\right)$ is the correct answer.