Question

The drift speed of electrons in a conductor is estimated to be only a few mm s-1, But on closing a circuit, how current is established almost instantly in an electric circuit?

• A. Electrons are accelerated towards the positive end of the conductor while their velocity increases towards the other end
• B. Drift velocity of electrons increases
• C. Electric field is established throughout the circuit with the speed of an electromagnetic wave, causing at every point local electron drift causing current.
• D. The electrons drift towards the negative end

Answer 1

Answer: (C)

Electric field is established throughout the circuit with the speed of an electromagnetic wave, causing at every point local electron drift causing current.

Answer 2

The correct option is(C):Electric field is established throughout the circuit with the speed of an electromagnetic wave, causing at every point local electron drift causing current.