Kindly solve the question ..... It`s from electrostatics, the answer is c.....

(1) fir net charge on inner solid sphere , Q=integral(e•dv). --> dv=4πr^2•dr, e=e°/r hence Q=integral((e°÷r) × 4πr²×dr) -->.Q=integral(4πre°•dr) = "2π(R1)² =Q1". Q2=(-¶•(sirface area)) = (-¶•4πr²). Since it is given that net cherge is zero , Q1 +Q2 = 0 --> (e°•2πR1²) = (¶•4πR2²) --> R2²÷R1² = e°÷2¶ (my mobile don`t support sigma so i have used "¶" in place of it) please do approve my answer.

Approved