Question

Two identical charges having positive charges are placed 3m apart repel each other with a force of 8×10^-3n. Now charges are connected by a metallic wire they begin to repel each other with a force of 9×10^-3n. Find the initial charges on the spheres

Answer 1

Let q1 and q2 charges on both spheres respectively.

both charged particles are separated 3m apart. now force of repulsion between them is F = kq1q2/(3)² = 8 × 10^-3

or, 9 × 10^9 × q1q2/9 = 8 × 10^-3

or, 10^9 × q1q2 = 8 × 10^-3

or, q1q2= 8 × 10^-12 .......(1)

now, charged particles are connected by a metallic wire they begin to repel each other with a force of 9 × 10^-3 N.

due to metallic wire, charge transfer from one sphere to other untill both attains common potential or, common charges [ because both sphere sphere are identical so, common potential attains means common charge ]

then, charge on each sphere = (q1 + q2)/2

so, force between them, F = k(q1+q2)²/4(3)² = 9 × 10^-3

or, 9 × 10^9 × (q1 + q2)²/36 = 9 × 10^-3

or, (q1 + q2)² = 36 × 10^-12

or, (q1 + q2) = 6 × 10^-6 .....(2)

from equations (1) and (2),

q1 = 4 × 10^-6 C and q2 = 2 × 10^-6C and vice - versa.

Answer 2

Answer:

Explanation:

See the attachment given below

Hope it helps you ..