Q. The number of turns in primary coil of a transformer is 20 and the number of turns in the secondary is 10. If the voltage across the primary is 220 V, what is the voltage across the secondary?
A) 110 V
B) 130 V
C) 190 V
D) 310 V
Explanation
(a) Given, $N_{P} = 20,\ N_{S} = 10,\ \ \ e_{p} = 220V$
$\therefore$ Transformation ratio, k
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \frac{e_{s}}{e_{p}} = \frac{N_{s}}{N_{p}}$
or $e_{s} = \frac{N_{s}}{N_{p}} \times ep$
$\ \ \ \ \ \ \ \ \ \ \ = \frac{10}{20} \times 220 = 110\ V$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.