Question

A power transmission line feeds input power at $2300V$ to a step-down transformer, with its primary winding having $4000$ turns. What should be the number of turns in the secondary winding in order to get output power at $230V$?

• A. $300$
• B. $250$
• C. $400$
• D. $450$

Answer 1

Answer: (C)

$400$

Input voltage in primary winding $V_1=2300$ $V$

Output voltage in secondary winding $V_2=230$ $V$

Number of turns in primary winding $N_1=4000$

Let number of turns in secondary winding be $N_2$

Using $\frac{V_1}{N_1}=\frac{V_2}{N_2}$

$\therefore$ $\frac{2300}{4000}=\frac{230}{N_2}$ $⟹N_2=400$ turns