Question

A long, straight wire perpendicular to this page carries a current of 5.15 A directed into the page. Find the magnetic field at the following points, all 10.5 cm from the wire.

10.5 cm to the left, directly below, to the right, AND directly above the wire. (magnitude and direction)

Answer 1

here,

current in the wire , I = 5.15 A

distance of point from the wire , r = 10.5 cm = 0.105 m

the magnitude of feild , B = u0 * I /( 2*pi*r)

B = 1.26 * 10^-6 * 5.15 /(2 *pi * 0.105)

B = 9.84 * 10^-6 T

for the direction of force

using the right hand thumb rule

the direction of feild at the 10.5 cm to the left is UPWARDS

the direction of feild at the 10.5 cm directly below is TO THE LEFT

the direction of feild at the 10.5 cm to the right is downWARDS

the direction of feild at the 10.5 cm directly above is TO THE RIGHT