# EMF - need help - physics

#### brenton

EMF - need urgent help - physics

hey, i have a physics quiestion which i am stuck on any help would be much appreciated

you are asked to design a generator to produce the same 50Hz, 240V(rms) as found in a domestic voltage outlet

The generator is made of a single flat coilbeing made to rotate in a uniform magnetic field of strength 0.08T. the coil may be of any surface area and have as many turns as you like, provided the area and number are "reasonable" values. the length of the coil is L, its width is W, and it spins at an angular rate (omega)w = 2Pi.50 rads/s

What values would you choose for thr area of the coil, A, and for the number of turns, N, that will provide this emf.

i have never done physics before so i dont even no what to begin...could comeone please run me though how i would attempt it..
thankyou

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#### Delta

How much do you know about electric and magnetic fields?

I would start with V=Blv, but unless that's known as a standard formula, you'd need to go back a few steps.

#### CharlesP

If I were designing a dynamo one of the first things I would consider is the energy which could be stored in the iron. You would need to know the area and length of the iron path. Also the susceptibility of the iron and the distance of the air gap. Then you can find out how many ampere turns can bring this to saturation and finally from the energy and frequency you may get the maximum power you can hope for. Then of course you want to know if you can fit your wire in the remaining space. This is hardly half of it. Maybe a start. Good luck.

"EMF - need help - physics"

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