A long wire with a small current element of length 1 cm is placed at the origin and carries a current of 10 A along the X-axis. Find out the magnitude and direction of the magnetic field due to the element on the Y-axis at a distance 0.5 m from it.

Explanation

Here length of current element `dl = 1 cm = 0.01 m, ` current I = 10 A, distance of the point from current element `r = 0.5 m and theta = 90^@`
`:.` Magnitude of magnetic field `dB = (mu_0)/(4 pi) (I dl sin theta)/(r^2)`
`implies " " dB = (10^(-7) xx 10 xx 0.01 xx sin 90^@)/((0.5)^2) = 4.0 xx 10^(-8) T`
The magnetic field acts along +z axis.