The primary winding of a transformer has 500 turns and its secondary has 5000 turns. The primary is connected to an a.c. supply of 20 V, 50 Hz. The secondary will have an output of:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 200 V, 50 Hz
In an ideal transformer the output voltage is in the same ratio to the input voltage as the number of turns, and the frequency is not changed.
\( \displaystyle \frac{V_s}{V_p} = \frac{N_s}{N_p} \Rightarrow V_s = 20\,\mathrm{V}\times\frac{5000}{500} = 200\,\mathrm{V} \)
The secondary has 10 times the turns, so it is a step-up transformer; the frequency stays at 50 Hz.