Question 168: Magnetism and Matter

Question

Figure A and B shown to long straight wires of circular cross-section (a and b with a < b), carrying current I which is uniformly distributed across the cross-section. The magnitude of magnetic field B varies with radius r and can be represented as :
![](https://imagex.cdn.examgoal.net/1ks447gfn/a0d5845e-29ce-4204-bc29-ef17da80fff1/79667430-f8c7-11eb-8274-7f1d731e697f/file-1ks447gfo.jpg)

Accepted Answer

Graph for wire of radius R :
As b > a
B
a
> B
b
${B_a} = {{{\mu _0}i} \over {2\pi a}}$
${B_b} = {{{\mu _0}i} \over {2\pi b}}$
![](https://imagex.cdn.examgoal.net/1ks44cei3/d98ab572-a6cc-4f6b-b161-a788995ada97/02f43ac0-f8c8-11eb-a1d4-495922108aa7/file-1ks44cei4.png)

Answer

Answer

Answer

Answer

Magnetism and Matter

Figure A and B shown to long straight wires of circular cross-section (a and b with a < b), carrying current I which is uniformly distributed across the cross-section. The magnitude of magnetic field B varies with radius r and can be represented as :

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