Question

In an a.c. circuit, resistance of $R\Omega$ is connected in series with an inductance $L.$ If phase angle between voltage and current be ${45}^{\circ }.$ The value of inductive reactance is-

• A. $\frac{R}{4}$
• B. $\frac{R}{2}$
• C. $R$
• D. $\sqrt{3}R$

Answer 1

The correct option is C $R$

Given,

The phase angle $\varphi ={45}^{\circ }$



In a.c. $\text{LR}$ circuit,

$\tan \varphi =\frac{V_L}{V_R}=\frac{I{X}_L}{IR}=\frac{X_L}{R}$

$\tan {45}^{\circ }=\frac{X_L}{R}$

$\Rightarrow X_L=R\tan {45}^{\circ }=R$

<!--td {border: 1px solid #ccc;}br {mso-data-placement:same-cell;}--> Hence, $\left(C\right)$ is the correct answer.