Question

In the given circuit if point $C$ is connected to the earth and a potential of $+2000V$ is given to point $A$, the potential at $B$ is

• A. $1500V$
• B. $1000V$
• C. $500V$
• D. $400V$

Answer 1

The correct option is A $1500V$

$Ceq=\frac{15}{4}\mu F$

Total charge $Q=Ceq.V=\frac{15}{4}\times 2000\times {10}^{-6}C$

$=7.5mC$

Now, $Q_{AB}=\frac{7.5}{4}mC\Rightarrow C_{AB}.V_{AB}=\frac{7.5}{4}mC\Rightarrow 5\times {10}^{-6}{V}_{AB}=\frac{7.5}{4}mC\Rightarrow V_{AB}=\frac{1.5}{4}\times {10}^{3}V=\frac{1500}{4}=375V\Rightarrow V_A-V_B=375V\Rightarrow V_B=2000-375=1625V$