Q. A 100% efficient transformer has 100 turns in the primary and 25 turns in its secondary coil. If the current in the secondary coil is 4 amp, then the current in the primary coil is
A) $1\ amp$
B) $4\ amp$
C) $8\ amp$
D) $16\ amp$
Explanation
(a) For 100% efficient transformer
$V_{s}i_{s} = V_{p}i_{p} \Rightarrow \frac{V_{s}}{V_{p}} = \frac{i_{p}}{i_{s}} = \frac{N_{s}}{N_{p}} \Rightarrow \frac{i_{p}}{4} = \frac{25}{100} \Rightarrow i_{p} = 1\ A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.