Two capacitors of capacities 2C and C are joined in parallel and charged up to potential V.

Question:

Two capacitors of capacities 2C and C are joined in parallel and charged up to potential V. The battery is removed and the capacitor of capacity C is filled completely with a medium of dielectric constant K. The potential difference across the capacitors will now be : 

  1. $\frac{\mathrm{V}}{\mathrm{K}+2}$

  2. $\frac{\mathrm{V}}{\mathrm{K}}$

  3. $\frac{3 \mathrm{~V}}{\mathrm{~K}+2}$

  4. $\frac{3 \mathrm{~V}}{\mathrm{~K}}$


Correct Option: , 3

Solution:

$V_{C}=\frac{2 C V+C V}{K C+2 C}$

$=\frac{3 V}{K+2}$

Leave a comment