The ratio of secondary to primary turns in a transformer is \( 5 : 4 \). If input voltage is \( 200 \) V, then the output voltage is
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 250\ \mathrm{V} \)
For an ideal transformer the voltage per turn is the same in both coils, so the voltages are in the ratio of the turns.
\( \displaystyle \frac{V_{s}}{V_{p}} = \frac{N_{s}}{N_{p}} \quad\Rightarrow\quad V_{s} = 200\ \mathrm{V} \times \frac{5}{4} = 250\ \mathrm{V} \)
Since \( N_{s} \gt N_{p} \), this is a step-up transformer.