Question

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

Options

• 300

• 250

• 400

• 450

Answer 1

400

Explanation:

Input voltage, V₁ = 2300

Number of turns in the primary coil, n₁ = 4000

Output voltage, V₂ = 230 V

Number of turns in secondary coil = n₂

Voltage is related to the number of turns as:

`"V"_1/"V"_2 = "n"_1/"n"_2`

`2300/230 = 4000/"n"_2`

n₂ = `(4000 xx 230)/2300` = 400

Hence, there are 400 turns in the second winding.