Answer:
0.35701 T
Explanation:
[tex]B_i[/tex] = Initial magnetic field
[tex]B_f[/tex] = Final magnetic field
[tex]\phi[/tex] = Magnetic flux
t = Time taken = 4.17 ms
N = Number of turns = 510
[tex]\epsilon[/tex] = Induced emf = 10000 V
r = Radius = 0.27 m
A = Area = [tex]\pi r^2[/tex]
Induced emf is given by
[tex]\epsilon=-N\frac{d\phi}{dt}\\\Rightarrow \epsilon=-N\frac{B_fAcos90-B_iAcos0}{dt}\\\Rightarrow \epsilon=N\frac{B_iA}{dt}\\\Rightarrow B_i=\frac{\epsilon dt}{NA}\\\Rightarrow B_i=\frac{10000 \times 4.17\times 10^{-3}}{510\times \pi 0.27^2}\\\Rightarrow B_i=0.35701\ T[/tex]
The magnetic field strength needed is 0.35701 T
