Finding the EMF, Magnetic Flux. I cannot do this question? Help.

This would make a great conversation in a pub.

But a tough question indeed, what exam board is this? I couldn't solve it mathematically so I'll try to revise some magnetic stuff and try again.

I came across this question and I am not happy with the answer.

I find this question impossible. Please help me.

I don't know if this is an invalid question because I find it difficult, but if it is possible, please enlighten me. Thank you.

Can you solve it? Thank you.

There is a solution but I disagree with it since the length multiplied by its diameter is surely not the area.

No exam board, just a question made by someone.

http://www.antonine-education.co.uk/Pages/Physics_4/Magnetism/MAG_05/answer_to_question_3.htm

Sorry, didn't see this post before editing my previous one.

The volume of the cylinder is pr²l = 0.4 m³

Are you talking about this? pr² is obviously the area and l is the length of the cylinder of water that would flow in one second. Multiply them together and you get the volume which you are given. Think about it like this: imagine you have an empty pipe and you let water flow in it for exactly one second. Then you want to find the length of water in your pipe.

I agreed with the mark scheme up until it multiplied the length by "0.35".

The pipe is circular is its width is always equal to the diameter: w = 0.35. And then it's just subbing in into emf = vwB. This is the first time I saw a question like this since I'm doing AQA but this follows from what it says in the notes.

Ah, I get it now. I was thinking about the area of the circle when I should've been thinking about the other area. It makes perfect sense now. Thanks for the enlightment.