Question

A transformer with 1000 turns on the primary coil is used to decrease the voltage from 2500 V to 120 V for home use. How many turns should be in the secondary coil? A) 84 turns B) 48 turns C) 6.4 turns D) 5 turns E) 250 turns

Answer 1

Answer:

The number of turns in the secondary coil is 48.

(B) is correct option.

Explanation:

Given that,

Number of turns on primary coil= 1000

Primary voltage = 2500 V

Secondary voltage = 120 v

We need to calculate the turns  in the secondary coil

Using relation between voltage and number of turns in primary and secondary coil

$\dfrac{V_{s}}{V_{p}}=\dfrac{N_{s}}{N_{p}}$

Put the value into the formula

$\dfrac{120}{2500}=\dfrac{N_{s}}{1000}$

$N_{s}=\dfrac{120}{2500}\times1000$

$N_{s}=48\ turns$

Hence, The number of turns in the secondary coil is 48.