Q. A solenoid is $1.5\ m$ long and its inner diameter is $4.0\ cm$. It has three layers of windings of 1000 turns each and carries a current of $2.0\ amperes$. The magnetic flux for a cross-section of the solenoid is nearly
A) $2.5 \times 10^{- 7}\ weber$
B) $6.31 \times 10^{- 6}\ weber$
C) $5.2 \times 10^{- 5}\ weber$
D) $4.1 \times 10^{- 5}\ weber$
Explanation
(b) $\phi = \mu_{0}niA = 4\pi \times 10^{- 7} \times \frac{3000}{1.5} \times 2 \times \pi\left( 2 \times 10^{- 2} \right)^{2}$
$= 6.31 \times 10^{- 6}Wb$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.