An `RC-` circuit, with `R = 600kOmega` and `C = 10muF`, is connected to a `5.0-V` battery unit the capacitor is fully charged. Then, the battery is suddenly replaced with a new `3.00-V` battery of opposite polarity. At what time after this replacement will the energy stored in the capacitor be zero ? (given that `e ~~ (8)/(3)` )

Options

A. `12 s`
B. `6 s`
C. `3 s`
D. `1.5 s`

Answer

B

Explanation

`(3 "volt")/((3 + 5) "volt") = e^(-t//tau) , tau = RC = 6s`
`:. T ~~ 6 s`