# A  4 µF capacitor and a resistor of 2.5M? are in series with 12V battery.FInd the time after which the potentiak difference across the capacitor is 3times the potential difference across the resistor.[given ln(2)=0.693]A)13.86sB)6.93sC)7sD)14s

Arun Kumar IIT Delhi
$E_{C}=E(1-e^{-t/RC})=E(1-e^{-t/10})=3E/4 \\=>e^{-t/RC}=1/4 \\=>10*ln(4)=t$