JEE Main 2025 · 29 January · evening · Single correct · +4 / −1
Match List - I with List - II.
Choose the correct answer from the options given below:
| List - I | List - II |
|---|---|
| (A) Magnetic induction | (I) Ampere meter² |
| (B) Magnetic intensity | (II) Weber |
| (C) Magnetic flux | (III) Gauss |
| (D) Magnetic moment | (IV) Ampere meter |
- (a) (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
- (b) (A)-(III), (B)-(II), (C)-(I), (D)-(IV)
- (c) (A)-(III), (B)-(IV), (C)-(I), (D)-(II)
- (d) (A)-(I), (B)-(II), (C)-(III), (D)-(IV)
Answer and solution
Answer (a) (A)-(III), (B)-(IV), (C)-(II), (D)-(I)
Solution
Physics sir · 3 steps
Give each quantity its unit, and watch the power of the metre: A/m is intensity, A m² is moment.
- Recall the definitions. Magnetic induction B comes from force on a moving charge, magnetic intensity H from current per unit length, flux is Φ = BA, and a current loop has moment m = IA.
Quantity Defining relation Unit Match (A) Magnetic induction B F = qvB tesla in SI, gauss in CGS (1 G = 10⁻⁴ T) (III) (B) Magnetic intensity H H = nI (turns per metre times current) A m⁻¹, the ampere meter in the list (IV) (C) Magnetic flux Φ Φ = BA weber (1 Wb = 1 T m²) (II) (D) Magnetic moment m m = IA A m² (I) - Keep the metre straight. Current per unit length gives A m⁻¹, so that is H. Current times area gives A m², so that is the moment m.
- So. The matching is (A)-(III), (B)-(IV), (C)-(II), (D)-(I), which is option (a).
The idea to keep. Build each magnetic unit from its definition: B in tesla or gauss, H = nI in A/m, Φ = BA in weber, m = IA in A m². Do not memorise the units as a loose list.
Answer from the NTA final answer key. Solution by PrepWiser.