Question

Three capcaitors of capacities `1muF, 2muF` and `3muF` are charged by `10V, 20V` and `30V` respectively. Now positive plates of first two capacitors are connected with the negative plate of third capacitor on one side and negative plates of first wo capacitors are connectes with positive of third capacitor on the other side. Find
a. common potential V
b. final charges on different capacitors.

Answer 1

Total charge on all three capacitors =`40muC`
Total capacity `(1+2+32)muF=6muF`
a. common potential
`V=("Total charge")/("Total capacity")`
`=(40muC)/(6muF)=20/3vol t`
b. `q_1C_1V=(1muF)(20/3)=20/3muC`
`q_2=C_2V=(2muF)(20/3)=40/3muC`
`q_3=C_3V=(3muF)(20/3)=20muC`