Question

Two particles having positive charges + Q and + 2Q are fixed at equal distance x from centre of an conducting sphere having zero net charge and radius r as shown. Initially the switch S is open. After the switch S is closed, the net charge flowing out of sphere is –

• A. $\frac{Qr}{x}$
• B. $\frac{2Qr}{x}$
• C. $\frac{3Qr}{x}$
• D. $\frac{6Qr}{x}$

Answer 1

Answer: (C)

$\frac{3Qr}{x}$

Answer 2

Initially the potential at centre of sphere is

V_C =

After the sphere grounded, potential at centre becomes zero. Let the net charge on sphere finally be q.

\ $\frac { 1 } { 4 \pi \varepsilon _ { 0 } }$ + = 0 or q =

\The charge flowing out of sphere is