QJEEM11Phb05e: JEE Main 2011 Physics - Class 12 JEEM11Phb05e Solution: A current I flows in an infinitely long wire with cross section …

Question

Verified Solution • 2025–26 Session moderate

A current

I

flows in an infinitely long wire with cross section in the form of a semi-circular ring of radius

R .

The magnitude of the magnetic induction along its axis is:

Accepted Answer

Current in a small element,

d l = \frac{d θ}{π} I

Magnetic field due to the element

d B = \frac{μ_{0}}{4 π} \frac{2 d l}{R}

The component

d B

\cos θ,

of the field is canceled by another opposite component.

Therefore,

AIEEE 2011 Physics - Magnetic Effect of Current Question 189 English Explanation

B_{n e t} = \int d B \sin θ = \frac{μ_{0} I}{2 π^{2} R_{0}}

\int_{0}^{π} \sin θ d θ = \frac{μ_{0} I}{π^{2} R}

Step-by-Step Verified Solution