The field normal to the plane of a coil of ‘n’ turns and radius ‘r’ which carries a current ‘i’ is measured on the axis of the coil at a small distance ‘h’ from the centre of the coil. This is smaller, than the field at the centre by the fraction.

see full answer

High-Paying Jobs That Even AI Can’t Replace — Through JEE/NEET

🎯 Hear from the experts why preparing for JEE/NEET today sets you up for future-proof, high-income careers tomorrow.

An Intiative by Sri Chaitanya

$\frac{2}{3} \frac{h^{2}}{r^{2}}$

$\frac{2}{3} \frac{r^{2}}{h^{2}}$

$\frac{3}{2} \frac{h^{2}}{r^{2}}$

$\frac{3}{2} \frac{r^{2}}{h^{2}}$

answer is A.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Field at the centre $B_{c} = \frac{μ_{0} ni}{2 r}$
Field along the axis $B_{a} = \frac{μ_{0} {nir}^{2}}{2 {(h^{2} + r^{2})}^{3 / 2}}$
$= B_{C} \times (1 - \frac{3}{2} \frac{h^{2}}{r^{2}})$
hence this is smaller than the field at the centre by the fraction $= \frac{3 h^{2}}{2 r^{2}}$

Watch 3-min video & get full concept clarity

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE