Switches in figures (a) and (b) are closed at t = 0

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7.Alternating Current

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The switches in figures $(a)$ and $(b)$ are closed at $t = 0$

A

The charge on $C$ just after $t = 0$ is $EC.$

B

The charge on $C$ long after $t = 0$ is $EC.$

C

The current in $L$ long after $t = 0$ is $E/R.$

D

Both $(B)$ and $(C)$

Solution

When a capacitor is connected to a battery for a long time, it behaves as a open circuit.

Hence, from Kirchoffs Voltage law$:$

$E-\frac{q}{C}=0$

$\Longrightarrow q=E C$

When an inductor is connected to a battery for a long time, it behaves as a short circuit.

Hence, from the Kirchoff's Voltage law$:$

$E-I R=0$

$\Longrightarrow I=\frac{E}{R}$

Standard 12

Physics

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