Question

For a C.T. the turns ratio is defined as the _________

(a) n = ^Np ⁄ Ns

(b) n =  ^1 ⁄ Np

(c) n = Ns

(d) n =  ^Ns ⁄ Np

I have been asked this question during an interview for a job.

This interesting question is from Ratios of Instrument Transformers in chapter Extension of Instrument Ranges of Electrical Measurements

Answer 1

Correct option is (d) n =  ^Ns ⁄ Np

For explanation I would say: For a current transformer, the turns ratio is defined as the ratio of the number of turns in the secondary winding to the number of turns in the primary winding.

n =  ^Ns ⁄ Np

where, n is the turns ratio

            Ns is the secondary turns

            Np is the primary turns.