Answer:
0.25 T
Explanation:
F = Force required to keep the bar moving = 0.080 N
B = magnitude of magnetic field = ?
L = length of the bar = 50 cm = 0.50 m
v = speed of the bar = 0.50 m/s
R = resistance of the bar =0.10 Ω
Force is given as
[tex]F = \frac{B^{2}L^{2}v}{R}[/tex]
[tex]0.08 = \frac{B^{2}(0.50)^{2}(0.50)}{0.10}[/tex]
B = 0.25 T