A circuit contains capacitors of capacitance $500\mu \mathrm{F}$ and $2000\mu \mathrm{F}$ In series with each other and in series with a resistance of $2.5\mathrm{k}\Omega$.

Calculate the charge on the capacitor plates when there is a potential difference of $50 \mathrm{V}$ Across the plates.

A circuit contains capacitors of capacitance $500\mu \mathrm{F}$ and $2000\mu \mathrm{F}$ in series with each other and in series with a resistance of $2.5\mathrm{k}\Omega$. Calculate the time taken for the charge on the plates to fall to $5\%$ of the charge when there was a p.d. of $50 \mathrm{V}$ across the plates.