What will happen if the primary of a transformer is connected to DC supply?

• A. Transformer will operate with high efficiency
• B. Transformer will operate with low efficiency
• C. No effect
• D. Transformer may start to smoke and burn

Answer: (D)

transformer works on principle of faraday's law of electromagnetic induction. So if D.C supply use, no indction are produced and due to this E.M.F not induced in winding and transfer of electrical energy is not possible.