Question 323: AC fundamentals

Question

In series LCR circuit, 'R' represents resistance of electric bulb. If the frequency of a.c. supply is doubled, the value of inductance ' $L$ ' and capacitance 'C' should be

Accepted Answer

In an LCR circuit
$$\begin{aligned}
I=\frac{E}{Z} & =\frac{E}{\sqrt{R^2+\left(X_L-X_cight)^2}} \
& =\frac{E}{\sqrt{R^2+\left(2 \pi \mathrm{fL}-\frac{1}{2 \pi \mathrm{fC}}ight)^2}}
\end{aligned}$$
To keep I constant, if f is doubled both L and C should be halved.

Answer

both doubled.

Answer

made four times.

Answer

made eight times.

Answer

both halved simultaneously.

AC fundamentals

In series LCR circuit, 'R' represents resistance of electric bulb. If the frequency of a.c. supply is doubled, the value of inductance ' L ' and capacitance 'C' should be

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