Question

In a pure capacitive circuit if the frequency of ac source is doubled, then its capacitive reactance will be

• A. remains same
• B. doubled
• C. halved
• D. zero

Answer 1

Answer: (C)

halved

Answer 2

Capacitive reactance, $X_{C}=\frac{1}{2\pi\upsilon C}$ $\Rightarrow X_{C} \propto \frac{1}{\upsilon}$ $\therefore \frac{X_{C_1}}{X_{C_2}}= \frac{\upsilon_{2}}{\upsilon_{1}}=\frac{2\upsilon}{\upsilon}=2$ $\Rightarrow X_{C_2}=\frac{X_{C_1}}{2}$