WAEC - Physics (2019 - No. 13)

If the efficiency of a transformer is 100%, which of the following equations would be correct?

N\(_p\)E\(_p\) = N\(_s\)E\(_s\)

N\(_s\)I\(_p\)= N\(_p\)I\(_s\)

N\(_s\)I\(_s\) = N\(_p\)I\(_p\)

I\(_p\)E\(_s\) = I\(_s\)E\(_p\)