Magnetic Flux & Flux Linkage Explained | A-level Physics

Why can the same magnetic field give a coil a different magnetic flux? Learn magnetic flux and flux linkage for A-level Physics, with coil diagrams, worked calculations and an introduction to the search-coil practical. We explain the normal to a coil, why the cosine appears, and how to distinguish the flux through one turn from the total flux linkage. Work through area conversion from cm² to m², a 50-turn coil example, negative flux and the effect of changing orientation. Lesson notes and worked examples: https://inklearning.co.uk/physics/mag... Practice questions with mark schemes: https://inklearning.co.uk/physics/pra... Search-coil practical: https://inklearning.co.uk/physics/pra... Units refresher — prefixes and area conversions: https://inklearning.co.uk/physics/mea... Next topic — electromagnetic induction, Faraday and Lenz: https://inklearning.co.uk/physics/mag... Chapters 00:00 Same field, different flux 00:18 Magnetic flux, area and units 01:18 The normal and the cosine factor 02:11 The angle-to-the-plane trap 02:28 Flux linkage and number of turns 03:11 Worked example: flux and linkage 04:15 Rotating the coil to 60° 04:36 Negative flux and the cosine graph 05:04 What changes flux linkage? 05:22 Search coil and oscilloscope 06:29 Recap and next steps Key relationships Φ = BA cos θ for a flat area in a uniform magnetic field. NΦ = NBA cos θ when every turn links the same flux. θ is measured between the field and the normal to the coil's plane. Magnetic flux: weber (Wb). Flux linkage: weber-turns. In the practical, the oscilloscope measures induced voltage. The angle comparison uses an alternating field with fixed amplitude and frequency, the same coil and a fixed coil position. #MagneticFlux #FluxLinkage #ALevelPhysics