Physics - Capacitor Question with Solution | TestHub

First let us calcualte ${\mathrm{R}}_{\mathrm{eq}}$

To calculate $R_{\text{eq }}$ short the battery and that $R_{\text{eq }}$ between the ends of the capacitor

${\mathrm{R}}_{\mathrm{eq}}=\frac{3\mathrm{R}\times \mathrm{R}}{4\mathrm{R}}+\mathrm{R}=\frac{3\mathrm{R}}{4}+\mathrm{R}=\frac{7\mathrm{R}}{4}$

Hence time constant $=\frac{7\mathrm{RC}}{4}$