A capacitor of capacitance C₁ = $1.0 \mu F$ withstands a maximum voltage V₁ = 6.0 kV while capacitor of capacitance C₂ = $2.0\mu  F$ withstands the maximum voltage = 4.0 kV. What maximum voltage will the system of these capacitors withstand if they are connected in series?

9 kV

Charge that capacitor C₁ can hold is

            q₁ = C₁V₁ = 1 x 10^–6 x 6 x 10³ C = 6000 mC

            Charge with C₂ can hold is

            q₂ = C₂V₂ = 2 x 10^–6 x 6 x 10³ C = 12000 m C

            In series the charge that each must hold is the least value i.e., 6000 mC.

            $V = \frac{6000}{1} + \frac{6000}{2} = 9KV$