Question

If charge on left plate of the $5\mu F$ capacitor in the circuit segment shown in the figure is $-20\mu C$, the charge on the right plate of $3\mu F$ capacitor is :

• A. $+8.57\mu C$
• B. $-8.57\mu C$
• C. $+11.42\mu C$
• D. $-11.42\mu C$

Answer 1

Answer: (A)

$+8.57\mu C$

If the charge on left plate of $5\mu F$ is $-20\mu C$, then the charge on right plate of $5\mu F$ is $+20\mu C$
So due to the polarization the charge on left plate of $3\mu F$ is negative and charge on right plate of $3\mu F$ is positive.
thus, charge on right plate of $3\mu F$ is $Q=\frac{3}{3+4}\times 20=\frac{60}{7}=8.57\mu C$