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?
Figure

Answer 1

Power is directly proportional to Square of Velocity

Explanation:

Answer is (b)

We know that Electromotive Force developed across the terminals of loop = $e = B\times v\times l$

If R is resistance of the loop, then

Power delivered to loop is given by -

$P = \frac {e^2}{R} = \frac {B^2v^2l^2}{R}$

⇒ P =$v\times v$

Or we can say, Power is directly proportional to square of velocity