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Question
Figure shows a conducting loop being pulled out of a magnetic field with a speed v. Which of the four plots shown in figure (b) may represent the power delivered by the pulling agent as a function of the speed v?
Solution
(b) b
The emf developed across the ends of the loop is given by
`e=Bvl`
If R is the resistance of the loop, then the power delivered to the loop is given by
`P=e^2/R=(B^2v^2l^2)/R`
`rArr P prop v^2`
This relation is best represented by plot b in the figure.
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