Q. An air core solenoid has 1000 turns and is one $metre$ long. Its cross-sectional area is $10\ cm^{2}$. Its self inductance is
A) $0.1256\ mH$
B) $12.56\ mH$
C) $1.256\ mH$
D) $125.6\ mH$
Explanation
(c) $L = \frac{\mu_{0}N^{2}A}{l} = \frac{4\pi \times 10^{- 7} \times (1000)^{2} \times 10 \times 10^{- 4}}{1}$
$= 1.256\ mH$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.