Magnetic Effects & Magnetism

JEE Main level, single correct, medium

52 of 276

Question 52 of 276

A solenoid of 12001200 turns is wound uniformly in a single layer on a glass tube 2m2m long and 0.2m0.2m in diameter. The magnetic intensity at the center of the solenoid when a current of 2A2A flows through it is:

Show answer and solution

Answer: (B) 1.2×103Am−11.2\times {10}^{3}A{m}^{-1}

Given,
Number of turns per metre n=12002n=\dfrac{1200}{2}
l=2m,d=0.2mandI=2Al=2m,d=0.2m\text{and}I=2A
Magnetic field at centre inside the solenoid is given by B=μ0nIB={\mu }_{0}nI, where, μ0{\mu }_{0} is the permeability constant.
Magnetic intensity is related to magnetic field by
H=Bμ0=μ0nIμ0=nI=(12002)(2)H=\dfrac{B}{{\mu }_{0}}=\dfrac{{\mu }_{0}nI}{{\mu }_{0}}=nI=\left(\dfrac{1200}{2}\right)(2)
⇒H=1.2×103Am−1\Rightarrow H=1.2\times {10}^{3}A{m}^{-1}

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.

More Physics practice

JEE Main Physics practice question on Magnetic Effects & Magnetism (Magnetic Field), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.