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leena19
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Homework Statement
A current flows in a circular loop consisting of a single turn.If the same wire is bent into a circular loop of 2 turns and the same current is passed through the loop,the magnetic flux density at the centre will change by a factor of ...?
(ans: 4 )
Relevant equations
B = (mu0 * N*I)/2r
The attempt at a solution
For the 1st loop,
B = (mu0 *I)/2r
To find B' after bending,
the length of the wire remains unchanged = 2*pi*r
so to form 2 circular loops the radius has to be halved for each loop?
which makes
B' = (mu0 * N*I)/(2r/2)
B' = (mu0 * 2*I)/(r) ?
so change in flux = B-B'/B
= 3
Thanks in advance.