Question

A positively charged glass rod is brought near uncharged metal sphere, which is mounted on an insulated stand. If the glass rod is removed, the net charge on the metal sphere is

• A. Zero
• B. 1.6 × 10^-19 C
• C. Positive Charge
• D. Negative Charge

Answer 1

The Correct Option is A

Given: 

• A positively charged glass rod is brought near an uncharged metal sphere.
• The sphere is mounted on an insulated stand.
• The glass rod is then removed.

Step 1: Understanding Electrostatic Induction

When a charged object (glass rod) is brought near a conductor (metal sphere), it induces charge separation. The negative charges in the metal sphere move towards the glass rod, while the positive charges move away.

Step 2: What Happens When the Glass Rod is Removed?

Since the metal sphere is not grounded and no charge transfer has occurred, the charge redistribution disappears after removing the glass rod. The net charge on the sphere remains zero.

Answer: The correct option is A (Zero).

Answer 2

When a positively charged glass rod is brought near an uncharged metal sphere, it causes the electrons in the metal sphere to move due to electrostatic induction. Since the glass rod is positively charged, it will attract the free electrons in the metal sphere, causing a slight negative charge to accumulate on the side of the sphere nearest to the rod, while the far side becomes slightly positively charged. However, because the metal sphere is mounted on an insulated stand and no charge is allowed to flow in or out, once the glass rod is removed, the sphere remains neutral.

Thus, the net charge on the metal sphere will be zero after the glass rod is removed, as no charge is transferred to or from the sphere.

\(\textbf{Correct Answer:}\) (A) Zero