JEE Main 2025 Jan 29 Shift 2, Physics Q17: Magnetism and Matter

Standard SI / CGS units of the magnetic quantities:

(A) Magnetic induction $B$: CGS unit is Gauss (SI is Tesla, $1$ T $=10^4$ G). $\to$ (III).

(B) Magnetic intensity $H$: defined via $H=B/\mu$, units Ampere per metre. $\to$ (IV).

(C) Magnetic flux $\Phi$: $\Phi =\int \vec{B}\cdot d\vec{A}$, SI unit Weber. $\to$ (II).

(D) Magnetic moment $\vec{M}$: for a current loop $M=IA$, units Ampere $\cdot$ metre${}^2$. $\to$ (I).

Hence (A)-(III), (B)-(IV), (C)-(II), (D)-(I), which is option (2).