CAPE Physics Unit 2 · 2009 · Paper 1 · Question Q10

Item 10 refers to the diagram below which shows a long air coil solenoid carrying a current, I, with a flux density of 40\text{ }\mu\text{T} along its centre line. If the solenoid is compressed so that its length, l, is reduced to half its original value, what would be the flux density along the centre line?

1. (A)20\text{ }\mu\text{T}
2. (B)80\text{ }\mu\text{T}
3. (C)120\text{ }\mu\text{T}
4. (D)160\text{ }\mu\text{T}

This question uses a figure or table from the paper — you'll see it when you practise.