An experiment on the Earth's magnetic field (5.5 10-5 T) is being carried out 4.8 m from an electric cable. What is the maximum allowable current in the cable if the experiment is to be accurate to 1.0% ?

Respuesta :

Answer:

13.2 A

Explanation:

Earth's magnetic field B= 5.5×10^{-5} T

the distance r= 4.8 m

the permeability of free space μ_o= [tex]4\pi\times10^{-7}T.m/A[/tex]

according to Biot Savart law

[tex]B= \frac{\mu_0 I}{2\pi r}[/tex]

therefore, current in the table is

[tex]I= \frac{B(2\pi r)}{\mu_0}[/tex]

[tex]= \frac{5.5\times10^{-5}\times2\pi\times4.8}{4\pi\times10^{-7}}[/tex]

solving we get I= 1320 A

if the experiment is to be accurate to 1.0%

then the allowed value of current in the cable

I'= I(1%)

= [tex]\frac{1}{100}\times1320[/tex]

= 13.2 A