Question

In series $LCR$ circuit voltage drop across resistance is $8V$, across inductor is $6V$ and across capacitor is $12V$. Then

• A. voltage of the source will be leading current in the circuit
• B. voltage drop across each element will be less than the applied voltage
• C. power factor of circuit will be $4/3$
• D. none of these

Answer 1

Answer: (D)

Since $\cos \varphi =\frac{R}{Z}=\frac{IR}{IZ}=\frac{8}{10}=\frac{4}{5}$
(Also $\cos \varphi$ can never be greater than $1$)
Hence, (c) is wrong.
Also $I{X}_C>I{X}_L\Rightarrow X_C>X_L$
$\therefore$ Current will be leading.
In an $LCR$ circuit,
$V=\sqrt{{\left(V_L-V_C\right)}^2+V_R^2}=\sqrt{(6-12{)}^2+8^2}$
$V=10$; which is less than voltage drop across capacitor.