Question

Given that the area immersed in the gap is changing as the coil enters the gap, what is the correct expression of Faraday's Law for this situation? That is, find the induced voltage as a function of the velocity of the glider, v, the flux density inside the magnetic gap, B, and other quantities you can measure from the video.

Answer 1

Complete Question

The complete question is  shown on the first uploaded image

Answer:

 The  induced emf  is  $\epsilon = B * l * v$

Step-by-step explanation:

Now assume that the coil is  shaped as a rectangle with length  $l$ and  width b

   This  implies that the area of the coil is  $A= l * b$

Now when it enter into the uniform magnetic field the magnetic flux due to its movement as stated in the question is mathematically represented as

        $\phi = BA$

=>    $\phi = B (l* b )$

Now the induced emf is  mathematically represented as

          $\epsilon = \frac{d\phi}{dt}$

=>       $\epsilon = B * l [\frac{db}{dt} ]$

The  $l$  is constant because as it glides to and from the magnetic field it is displaced along the horizontal plane while along the vertical plane it is constant

Here  $\frac{db}{dt} = v$

Where is the velocity the glide (i.e the coil)

So

       $\epsilon = B * l * v$