Question

Question No.1
The negative charge - 92 is fixed while positive charge 91 as well as the conducting sphere 'S'is free to move. If the system is released from rest,
Conducting
shell's
(A) both S and q1 move towards left
(B) 91 moves towards right while S moves towards left
(C) 91 remains at rest, S moves towards left
(D) Both q1 and S remain at rest​

Answer 1

The correct question is:

The negative charge −q₂ is fixed while positive charge q₁ as well as the conducting sphere 'S' is free to move. If the system is released from rest (the total charge on S being zero).

(A) both S and q₁ move towards left

(B) q₁ moves towards right while S moves towards left

(C) q₁ remains at rest, S moves towards left

(D) Both q₁ and S remain at rest​

Solution:

If the system is released from rest, q₁ remains at rest and S moves towards left

• The net charge inside the sphere is zero. So q₁ will not move when the system is released.
• Due to the charge q₁, a negative charge ‘-q₁’ will be induced on the inner surface of the sphere and a positive charge ‘q₁’ on the outer surface.
• When the system is released, the sphere moves towards left doe to the electrostatic force between the charges q₁ and -q₂
• Therefore Option(C) is correct