A capacitor of `20mu F` and charged to 200V is connected parallel with parallel with another capacitor of `10muF` and charged to 400V. Find the common potential.

Explanation

Data supplied,
`C_(1)=20 muF, =20 xx 10^(-6)F, C_(2)=10muF=10 xx 10^(-6)F, V_(t)=200V, " "V_(2)=400V`
`Q_(1)=C_(1)V_(1), Q_(2)=C_(2)V_(2) and Q=CV`
`C=C_(1)+C_(2)`
`V=Q/C =(C_(1)V_(1)+C_(2)V_(2))/(C_(1)+C_(2))`
Common potential, `V=((20 xx 200+10 xx 400) xx 10^(-6))/((20+10) xx 10^(-6)) =(4000 +4000)/(30)=(8000)/(30)=266.7"volts"`