The primary coil of a transformer is connected to an a. c. supply of 20 V, 50 Hz. The ratio of number of turns in primary to secondary is \( 1:10 \). The output across the secondary will be:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 200 V, 50 Hz
A transformer works by mutual induction: the same changing flux links both coils, so the emf per turn is the same in each. Hence the voltages are in the ratio of the turns, and the frequency does not change.
\( \displaystyle \frac{V_s}{V_p} = \frac{N_s}{N_p} \)
\( \displaystyle V_s = 20\,\mathrm{V} \times \frac{10}{1} \)
\( \displaystyle V_s = 200\,\mathrm{V} \)
The secondary emf follows the same flux variation as the primary, so its frequency stays 50 Hz.