If an electric wire is allowed to produce a magnetic field no larger than that of the Earth (0.55 x 10-4 T) at a distance of 25 cm, what is the maximum current the wire can carry?
we are given in the problem the following dimensions or specifications
B = 0.000055 T r = 0.25 m constant mu0 = 4pi10-7
The formula that is applicable from physics is
B = mu0I/(2pir) I = 2Bpir/mu0 I = 68.75 Amperes
Answer:
68.75 A
Explanation:
B = 0.55 x 10^-4 T, r = 25 cm = 0.25 m
Let the current be i.
The magnetic field due to a current carrying straight wire at a distance r is given by
B = μ0 / 4π x 2 i / r
0.55 x 10^-4 = 10^-7 x 2 x i / 0.25
i = 68.75 A