Two capacitor of capacitance `5 muF` and `10 muF` are charged to potential `40V` and `10V` respectively. Now the two capacitors ate connected with plates of same polarities together .
(A) the common potential will be `20V`
(B) the final charges of capacitors will be `100muC` and `200muC`
(c) the ratio of total energy stored in capacitors before and after connection is `3:2`
(D) the loss energy of system is `1500muJ`

Options

A. `A,B,C`
B. `B,C,D`
C. `A,B,D`
D. `A,B,C,D`

Answer

D

Explanation

Common potential
`V=(5xx40+10xx10)/(5+10)=20V,(A)` is O.K.
`Q'_(1)=5xx20=100muC,Q'_(2)=10xx20=200muC,(B)` is O.K.
`(U_(i))/(U_(f))=((1)/(2)xx5xx(40)^(2)+(1)/(2)xx10xx(10)^(2))/((1)/(2)(5+10)xx(20)^(2))=(3)/(2),(c)` is O.K.
`DeltaU=(1)/(2).(5xx10)/((5+10))(40-10)^(2)xx10^(-6)=1500muJ`,
(D) is O.K.