Question

Identify the correct combination for a step-down transformer.

(a) k < 1; Vs > Vp, Is > Ip, Ns < Np

(b) k > 1; Vs < Vp, Is > Ip, Ns > Np

(c) k > 1; Vs > Vp, Is < Ip, Ns > Np

(d) k < 1; Vs < Vp, Is > Ip, Ns < Np

The question was asked in semester exam.

Enquiry is from Alternating Current in division Alternating Current of Physics – Class 12

Answer 1

The correct option is (d) k < 1; Vs < Vp, Is > Ip, Ns < Np

The explanation is: For a step-down transformer, the voltage at the second terminal is lesser than the primary terminal, i.e. ➔ Vs < Vp. Similarly, the number of turns in the secondary winding is lesser than that in the primary winding, i.e. ➔ Ns < Np. Also, the current in the secondary coil is greater than that current flowing the primary coil, i.e. ➔ Is > Ip. So the transformation ratio will be lesser than 1. So, the correct combination is given as:

k < 1; Vs < Vp, Is > Ip, Ns < Np