Question

A non conducting spherical shell of diameter $10$ cm has a change of $1.6\times {10}^{-4}C$. A charge of $20$ C is placed at distance of $10$ cm from its centre, then force between them will be:-

• A. $2.88\times {10}^9$ N
• B. $16\times {10}^{13}$ N
• C. $3\times {10}^9$ N
• D. $6\times {10}^{-9}$ N

Answer 1

The correct option is A $2.88\times {10}^9$ N

The sphere will act like a point change

$F=\frac{1}{4\pi E_0}\frac{q.q_2}{(0.1{)}^2}$

$=9\times {10}^9\times \frac{1.6\times {10}^{-4}\times 20\times 100}{\left(0.01\right)}$

$=288\times {10}^9\times {10}^{-4}\times 100$

$=2.88\times {10}^{9}N$