MHT-CET Physics and Chemistry Full Test-6 PHY-Que-18 Solution

Q.18. The inductive reactance of a coil is ‘X_L‘. If the inductance of a coil is tripled and frequency of a.c. supply is doubled, then the new inductive reactance will be

A. \frac{2}{3} X_L

B. \frac{3}{2} X_L

C. \frac{1}{6} X_L

D. 6 \mathrm{X}_{\mathrm{L}}

Answer: D. 6 \mathrm{X}_{\mathrm{L}}

Explanation :-

X_L = \omega L = 2 \pi f L f_{\text{new}} = 2 f \text{ and } L_{\text{new}} = 3 L

Therefore, X_L^{\prime} = 2 \pi (2 f) 3 L

= 6 \times 2 \pi f L = 6 X_L