A solid wire of radius 10 cm carries a current of 5.0 A distributed uniformly over its cross section. Find the magnetic field B at a point at a distance (a) 2 cm (b) 10 cm and (c) 20 cm away from the axis. Sketch a graph of B versus x for 0ltxlt20 cm .

Explanation

Given `r= 10cm= 10xx10^(-2)m, i =5A `
(a) x = 2cm = 2xx10^(-2)m`
`. Again using circuital law
`B. 2pi (10xx10^(-2) = mu_oxx5xx210^(-2)`
`rArr B = (4pixx10^(-7)xx10^(-1)/(2pixx10^(-2)`
`=2xx10^(-6) T = 2muT`
(b)solve as above
(c ) Solve as above.