Question 48: AC fundamentals

Question

For the same resonant frequency, if L is changed from L to $${L \over 3}$$, then capacitance should change from C to

Accepted Answer

The resonant frequency of a LC circuit is given by
$$f = {1 \over {2\pi \sqrt {LC} }}$$
when $$L' = {L \over 3}$$, as per question,
$$f' = f \Rightarrow {1 \over {2\pi \sqrt {L'C'} }} = {1 \over {2\pi \sqrt {LC} }}$$
$$ \Rightarrow LC = L'C' \Rightarrow C' = {{LC} \over {L'}} = {{LC} \over {L/3}} = 3C$$

Answer

$${C \over 3}$$

Answer

$$3C$$

Answer

$${2 \over 3}C$$

Answer

$$2C$$

AC fundamentals

For the same resonant frequency, if L is changed from L to ${L \over 3}$, then capacitance should change from C to

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