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A capacitor `4 muF` charged to `50 V` is connected to another capacitor of `2 muF` charged to `100 V` with plates of like charges connected together. The total energy before and after connection in multiples of `(10^(-2) J)` isA. `1.5` and `1.33`B. `1.33` and `1.5`C. `3.0` and `2.67`D. `2.67` and `3.0`

Answer» Correct Answer - A
The total energy before connection
`= (1)/(2) xx 4 xx 10^(-6) xx (50)^(2) + (1)/(2) xx 2 xx 10^(-6) xx (100)^(2)`
`= 1.5 xx 10^(-2) J`
When connected in parallel
`4 xx 50 + 2 xx 100 = 6 xx V rArr V = (200)/(3)`
Total energy after connection
`= (1)/(2) xx 6 xx 10^(-6) xx ((200)/(3))^(2) = 1.33 xx 10^(-2) J`


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