Answer:
Part a)
[tex]EMF = 14 \times 10^{-3} V[/tex]
Part b)
[tex]EMF = 15.67 \times 10^{-3} V[/tex]
Explanation:
As we know that magnetic flux through the loop is given as
[tex]\phi = B.A[/tex]
now we have
[tex]\phi = B\pi r^2[/tex]
now rate of change in flux is given as
[tex]\frac{d\phi}{dt} = B(2\pi r)\frac{dr}{dt}[/tex]
now we know that
[tex]A = \pi r^2[/tex]
[tex]0.285 = \pi r^2[/tex]
[tex]r = 0.30 m[/tex]
Now plug in all data
[tex]EMF = (0.20)\times 2\pi\times (0.30) \times (0.037)[/tex]
[tex]EMF = 14 \times 10^{-3} V[/tex]
Part b)
Now the radius of the loop after t = 1 s
[tex]r_1 = r_0 + \frac{dr}{dt}[/tex]
[tex]r_1 = 0.30 + 0.037[/tex]
[tex]r_1 = 0.337 m[/tex]
Now plug in data in above equation
[tex]EMF = (0.20)\times 2\pi\times (0.337) \times (0.037)[/tex]
[tex]EMF = 15.67 \times 10^{-3} V[/tex]