In the given circuit, if the potential difference between $A$ and $B$ is $80 \mathrm{V},$ then the equivalent capacitance between $A$ and $B$, and the charge on $10 \mu \mathrm{F}$ capacitor respectively, are

Four capacitors marked with capacitances and break down voltages are connected as shown in the figure. The maximum emf of the source so that no capacitor breaks down is$\_\_\_\_\_\_\_$

In the given circuit, if the potential difference between $A$ and $B$ is $80 \mathrm{V},$ then the equivalent capacitance between $A$ and $B$, and the charge on $10 \mu \mathrm{F}$ capacitor respectively, are