u can solve it as-
as the capacitors can't withstand a p.d of not more than 400v,this implies that no. of capacitors in series should be >=1000/400 (p.d. gets distributed in series) =2.5=3(bcoz 2.5 capacitors r impossible to get). now let there r m branches s.t there r 3 capacitors in each branch. eq.capacitance in one branch=1/3 microfarad.(series connection)
now as there r m branches so equivalent capacitance should be=
1/3*m=2 ( bcoz m branches r in parallel)
m=6.
So ther r 6 rows & 3 capacitors in each row&that's the answer!!!!!
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