A current of `1*0A` flowing in the sides of an equilateral triangle of side `4*5xx10^-2m`. Find the magnetic fied at the centroid of the triangle.

Options

A. `4xx10^(-5)Wb//m^2`
B. Zero
C. `2xx10^(-5)Wb//m^2`
D. `8xx10^(-5)Wb//m^2`

Answer

A

Explanation

Here, side of the triangle , `l=4.5xx10^(-2)m` , current , I = 1 A magnetic field at the centre of the triangle .O. B = ?
From figure , `tan 60^@ =sqrt3 =1/(2d)`
`implies d = l/(2sqrt3)=((4.5xx10^(-2))/(2sqrt3))m`
Magnetic field , `B = (mu_0i)/(4pid) (cos theta_1 + costheta_2)`
Putting value of `mu = 4pi xx10^(-7) and theta_1 and theta_2` we will get `B = 4 xx10^(-5) Wb//m^2`