Number of identical $8\mu F$and 250V capacitors required to make a combination of $16\mu F$and 1000 V are

$\mathrm{N}=\text{ Number of capacitors in series in each row }=\frac{{\mathrm{V}}_{\text{eff }}}{{\mathrm{V}}_{\text{each }}}=\frac{1000\mathrm{V}}{250\mathrm{V}}=4$

$\text{ Effective capacitance of each row }=\frac{{\mathrm{C}}_{\text{each }}}{\mathrm{N}}=\frac{8\mu F}{4}=2\mu F$

$\text{ Net capacitance of systeml }=\left(C_{\text{effoiecchrow }}\right)\text{ 1n where }m=\text{ Number of icentical rows in parallel }$

$16=\left(2\right)\mathrm{m}\Rightarrow m=8$

$\text{ Total number of capacitors }=\mathrm{mn}=32$