Q. A closely wound flat circular coil of 25 turns of wire has diameter of $10\ cm$ and carries a current of $4\ ampere$. Determine the flux density at the centre of a coil
A) $1.679 \times 10^{- 5}tesla$
B) $2.028 \times 10^{- 4}tesla$
C) $1.257 \times 10^{- 3}tesla$
D) $1.512 \times 10^{- 6}tesla$
Explanation
(c) $B = 10^{- 7}\frac{2\pi ni}{r} = 10^{- 7} \times \frac{2 \times \pi \times 25 \times 4}{5 \times 10^{- 2}} = 1.257 \times 10^{- 3}T$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.