Q. A solenoid 60 mm long has 50 turns on it and is wound on an iron rod of 7.5 mm radius. Find the flux through the solenoid when the current in it is 3A. The relative permeability of iron is 600
A) 1.66 Wb
B) 1.66 nWb
C) 1.66 mWb
D) 1.66$\ \mu Wb$
Explanation
(c) $\phi = \mu_{r}\mu_{0}\frac{N^{2}}{l}Ai$
$\ \ \ = 600 \times 4\pi \times 10^{- 7} \times 50 \times 50\pi \times \frac{\left( 7.5 \times 10^{- 3} \right)^{2} \times 3}{6 \times 10^{- 1}}$
$\ \ \ = 1.66 \times 10^{- 3}Wb = 1.66mWb$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.