The relative permeability of the core of a solenoid is 400. The windings of the solenoid are insulated from the core and carry a current of 2 A. If the number of turns is 1000 per metre, then the magnetic intensity inside the core of the solenoid is A m⁻¹.

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(2) 2×10³. Given: μᵣ=400, I=2 A, n=1000 turns per metre. Idea: the magnetic intensity (the magnetising field) of a long solenoid depends only on the current and the winding density, H=nI. The core changes B, not H - that is exactly why H is a useful quantity. H=1000×2=2×10³ A m⁻¹. The relative permeability 400 is not needed: it enters only the field, B=μ₀μᵣ H, which here would be about 1 T. So the magnetic intensity inside the core is 2×10³ A m⁻¹.

The relative permeability of the core of a solenoid is 400. The windings of the solenoid are insulated from the core and carry a current of 2 A. If the number of turns is 1000 per metre, then the magnetic intensity inside the core of the solenoid is _____ A m⁻¹.

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