- #1
AlexPilk
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Homework Statement
In a uniform magnetic field with induction of 0.1 Teslas - a coil is located perpendicular to the lines of induction (I suppose it's something like a ring of wire, meaning N=1). Resistance = 2 Ohms. What is the area of the "ring" if when the field is switched on - it will charge 50 microcoulombs?
The Attempt at a Solution
The area can be found from this equation I believe: Ф=B*S*cosa --> S=Ф/(B*cosa)
B = 0.1 teslas
cos(90 degrees) = 0, which doesn't make a lot of sense, since the flux won't be 0 if the lines of the magnetic field are going straight into the "ring", so I must be doing something wrong and it = 1.
If so: S = Ф/0.1
Now I have to find the flux given the charge and resistance.
I know that the voltage induced = change in flux/change in time. V=dФ/dt
I=dq/dt. V=I*R, so dФ/dt=dqR/dt --> dФ=dqR
If so: S=(5*10^-5*2)/0.1=100*10^-5=10^-3 m^2.
Is it correct?