Question

A power transmission line feeds input power at 2300 V to a step down transformer with its primary windings having 4000 turns. The number of turns in the secondary in order to get output power at 230 V are 

(i) 4 

(ii) 40 

(iii) 400 

(iv) 4000

Answer 1

Answer is (iii) 400

Given E_i = 2300V

E₀ = 230V

N_p = 4000

N_s = ?

\(\frac{E_i}{E_0}=\frac{N_p}{N_s}\)

\(\frac{2300}{230}=\frac{4000}{x}\)

x = 400 = N_s = No of turns in secondary coil