Question

In a step-up transformer the turns ratio is $10.$ The input current of the transformer is $12.5\text{A}$ and the frequency is $50\text{Hz}.$ If the efficiency of the transformer is $80\%$, then the frequency of the output current will be

• A. $500\text{Hz}$
• B. $5\text{Hz}$
• C. $40\text{Hz}$
• D. $50\text{Hz}$

Answer 1

The correct option is D $50\text{Hz}$

Given:

Turns ratio$=10$
Input current, $I_P=12.5\text{A}$
Frequency, $f_P=50\text{Hz}$
Efficiency of the transformer, $\eta =80\%$

As, we know that in any transformer, the frequency of output current as well as the frequency of output voltage remains the same.
Only the magnitudes of voltage and current changes.

Hence, the frequency of current in the secondary coil will be $50\text{Hz}.$

Hence, option $\left(D\right)$ is correct.