Question

At what distance from a long, straight wire carrying a current of 5.3 A is the magnetic ?eld due to the wire equal to the strength of Earth

Answer 1

Answer 2

magnetic field due to a striaght wire B = mu_0*i/(2*pi*R)...

given that B = 4.5*10^-5 T...

i = 5.3 A...
mu_0 = 1.25664*10^-6...

distance R = ?...

R = mu_o*i/(2*pi*B) = (1.25664*10^-6*5.3)/(2*3.142*4.5*10^-5) = 0.0235 m = 2.35 cm

Answer 3

Biot-Savart Law - Magnetic field around a straight conductor carrying a current I.

B = ?_0 I/2?r

where:
B is strength of magnetic field in T.
?_0 is permeability of free space = 1.25664 x 10^ -6 T-m/A.
I is current in A.
r is distance from conductor in m.

So r = ?_0 I/2?B
r = (1.25664 x 10^ -6 T-m/A * 5.3A)/(2? * 4.5 x 10^ -5 T) = 0.02355 m = 2.3 cm

Answer 4

Apply B = uI/2pir

(4.5 X 10^-5) = (1.25664 X 10^-6)(5.3)/(2pi)(r)

r = .0236 m

That is 2.36 cm