Practice portal › Electromagnetic Induction › Magnetic Flux

A square of side L metre lies in the xy-plane in a region where the magnetic field is ⃗B = B₀(2̂i + 4̂j + 3̂k) T, where B₀ is a constant. The magnitude of the flux passing through the square is ______.

Asked in GSEB Board March 2023 · Flux through a surface

Answer: (2) 3B₀L² Wb

Step-by-step solution

Given: a square of side L in the xy-plane, so its area vector is ⃗A = L²̂k; ⃗B = B₀(2̂i + 4̂j + 3̂k) T.

Idea: flux is Φ = ⃗B · ⃗A; only the component of ⃗B along the normal to the surface counts.

Φ = B₀(2̂i + 4̂j + 3̂k) · L²̂k.

Since ̂i · ̂k = ̂j · ̂k = 0 and ̂k · ̂k = 1: Φ = 3B₀L².

So the flux through the square is 3B₀L² Wb.

Why the other options are wrong

More Magnetic Flux questionsAll Magnetic Flux questions →

Reading this solution needs no sign-in. You only sign in to practise against the clock and keep your progress.

Practise this with a timer