JEE Main 2022 (25 Jun, Shift 1) Physics Q40: A long…

Question

A long straight wire with a circular cross-section having radius R, is carrying a steady current I. The current I is uniformly distributed across this cross-section. Then the variation of magnetic field due to current I with distance r (r < R) from its centre will be :

(1) $B\propto r^2$
(2) $B\propto r$ Official answer
(3) $B\propto\frac{1}{r^2}$
(4) $B\propto\frac{1}{r}$

Official answer

Option 2

NTA final key.

Accepted Answer

Option 2: $B\propto r$

Answer

$B\propto r^2$

Answer

$B\propto r$

Answer

$B\propto\frac{1}{r^2}$

Answer

$B\propto\frac{1}{r}$

JEE Main 25 June 2022, Shift 1, Physics Q40

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