Question

The source of electromagnetic wave is-
1. electric charge in uniform motion
2. electric charge in rest
3. accelerated electric charge
4. uniform electric current in a wire

Answer 1

Correct Answer - Option 3 : accelerated electric charge

CONCEPT:

• In the case of electric current, the electrons flow in the wire but there are equal and opposite charges, that is the same number of protons are there in that wire which doesn't flow.
  • That's why the overall current-carrying wire is neutral and it can't produce an electric field.
• A charge at rest produces an electric field only.
• A charge moving with a constant velocity produces both electric fields as well as the magnetic field.
• A charge moving with some acceleration produces electromagnetic waves/fields only.

EXPLANATION:

• Since an accelerated electric charge produces EM waves. So the source of em wave is accelerated electric charge.
• Hence option 3 is correct.