Q. A 20$\mu F$ capacitor is connected to 45 V battery through a circuit whose resistance is 2000$\Omega.$ What is the final charge on the capacitor?

A) $9 \times 10^{- 4}C$
B) $9.154 \times 10^{- 4}C$
C) $9.8 \times 10^{- 4}C$
D) None of these
Explanation

(a) We know that in steady state the capacitor behaves like as an open circuit $ie$, capacitor will not pass the current.
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So, the potential difference across the capacitor = 45 V
Hence , the final charge on the capacitor is
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ q = CV$
Here , $C = 20\mu F,\ \ \ \ \ \ \ \ V = 45\ V$
$\therefore\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ q = 20 \times 10^{- 6} \times 45$
or $\ q = 900 \times 10^{- 6}\ $
or $\ q = 9 \times 10^{- 4}C\ $

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.