Question

The ratio of secondary and primary turns of step-up transformer is 4 : 1. If a current of 4 A is applied to the primary, the induced current in secondary will be

• A. 8 A
• B. 2 A
• C. 1 A
• D. 0.5 A

Hint:

In a step-up transformer, the current in the secondary is inversely proportional to the ratio of the turns in the secondary and primary coils.

Answer 1

The Correct Option is C

Step 1: Use the transformer current equation.
For an ideal transformer, the ratio of the currents in the primary and secondary is inversely proportional to the ratio of the number of turns: \[ \frac{I_1}{I_2} = \frac{N_2}{N_1} \] where \( N_1 \) and \( N_2 \) are the number of turns in the primary and secondary coils, respectively, and \( I_1 \) and \( I_2 \) are the currents in the primary and secondary coils.
Step 2: Calculate the secondary current.
Given the turn ratio is 4:1, the current in the secondary will be \( 1 \, \text{A} \). Final Answer: \[ \boxed{1 \, \text{A}} \]