Answer:
B = 0.126 T
Explanation:
As per Faraday's law we know that rate of change in magnetic flux will induce EMF in the coil
So here we can say that EMF induced in the coil is given as
[tex]EMF = \frac{\phi_2 - \phi_1}{\Delta t}[/tex]
initially the coil area is perpendicular to the magnetic field
and after one fourth rotation of coil the area vector of coil will be turned by 90 degree
so we can say
[tex]\phi_1 = NBAcos 0 = BA[/tex]
[tex]\phi_2 = NBAcos 90 = 0[/tex]
now we will have
[tex]EMF = \frac{NBA}{t}[/tex]
[tex]10,000 V = \frac{(500)(B)(\pi \times 0.45^2)}{4.01\times 10^{-3}}[/tex]
[tex]B = 0.126 T[/tex]