In a transformer, the input current and voltage are 3 A and 50 V respectively. The ratio of the number of turns in the primary coil to secondary coil is 5 : 3. The output current and voltage, respectively, are
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → \( 5\,\mathrm{A} \) and \( 30\,\mathrm{V} \)
In an ideal transformer the voltages are in the ratio of the turns, and since the power is conserved (\( V_pI_p = V_sI_s \)) the currents are in the inverse ratio.
\( \displaystyle \frac{V_s}{V_p} = \frac{N_s}{N_p} \;\Rightarrow\; V_s = 50 \times \frac{3}{5} = 30\,\mathrm{V} \)
\( \displaystyle \frac{I_s}{I_p} = \frac{N_p}{N_s} \;\Rightarrow\; I_s = 3 \times \frac{5}{3} = 5\,\mathrm{A} \)
Check: \( V_pI_p = 50 \times 3 = 150\,\mathrm{W} \) and \( V_sI_s = 30 \times 5 = 150\,\mathrm{W} \).