Question

A single-turn circular loop of radius 14 cm is to produce a field at its center that will just cancel the earth's magnetic field at the equator, which is 0.7 g directed north. the permeability of free space is 4 π × 10−7 t · m/a. find the current in the loop. answer in units of a

Answer 1

Answer:

49 A

Explanation:

We are given that

Number of turns,N=1

Radius,r=14 cm=$\frac{14}{100}=0.14 m$

1 m=100 cm

Magnetic field,B=0.7 G=$0.7\times 10^{-4} T$

$1G=10^{-4} T$

$\mu_0=4\pi\times 10^{-7} Tm/A$

We know that magnetic field

$B=\frac{\mu_0IN}{2\pi r}$

Substitute the values

$0.7\times 10^{-4}=\frac{4\pi\times 10^{-7}\times 1\times I}{2\pi\times 0.14}$

$I=\frac{0.7\times 10^{-4}\times 2\pi\times 0.14}{4\pi\times 10^{-7}\times 1}$

$I=49A$