Q. Turn ratio is 1.25. The step up transformer operates at 230 V and current through secondary is 2 A. Then current in primary is
A) 25 A
B) 100 A
C) 50 A
D) 20 A
Explanation
(c) Given;$\frac{N_{P}}{N_{S}} = \frac{1}{25},V_{P} = 230V,\ I_{s} = 2\ A$
For an ideal transformer
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \frac{N_{P}}{N_{S}} = \frac{V_{P}}{V_{S}} = \frac{I_{S}}{I_{P}}\ or\frac{N_{P}}{N_{S}} = \frac{I_{S}}{I_{P}}\ $
Or $I_{P} = I_{S} \times \frac{N_{P}}{N_{S}} = 2A \times \frac{25}{1} = 50A$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.