- #1
arl146
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Homework Statement
A circular metal ring, as shown on the diagram below, is constructed so as to expand or contract freely. In a region with a constant magnetic field Bo oriented perpendicular to it, the ring expands, with its radius growing with time as r=r0(1+[itex]\alpha[/itex]t2). As the ring expands and grows thinner, its resistance per unit length changes according to R=Ro(1+[itex]\beta[/itex]t2). Find the current induced in the ring as a function of time. To check your answer, suppose that B0 = 7.30 mT, r0 = 11.0 cm, R0 = 3.00 m, [itex]\alpha[/itex]= 0.245 × 10(-4) s(-2), and β = 0.500 × 10(-2) s(-2). What is the value of the induced current at t = 86.0 s? (Note: Give the direction of the current where when viewed from above a positive current will move counterclockwise.)
Homework Equations
I don't even know where to start ! Can you start with flux?
Flux=BA
The Attempt at a Solution
Again, no clue. help is definitely needed, so lost!
The picture doesn't show much, just the B0 points up ( guess you can just call it +y direction ) and the radius which of a circle is obvious. Help is greatly appreciated!