Question

The primary winding of a transformer has 100 turns and its secondary winding has 200 turns. The primary is connected to an ac supply of 120 V and the current flowing in it is 10 A. The voltage and the current in the secondary are

• A. 240 V, 5 A
• B. 240 V, 10 A
• C. 60 V, 20 A
• D. 120 V, 20 A

Answer 1

Answer: (A)

240 V, 5 A

Answer 2

$\frac{N_{s}}{N_{p}} = \frac{V_{s}}{V_{p}} \Rightarrow \frac{200}{100} = \frac{V_{s}}{120} \Rightarrow V_{s} = 240\mspace{6mu} V$

also $\frac{V_{s}}{V_{p}} = \frac{i_{p}}{i_{s}} \Rightarrow \frac{240}{120} = \frac{10}{i_{s}} \Rightarrow i_{s} = 5\mspace{6mu} A$