A long straight wire in the horizontal plane carries a current of 50 A in north to south direction. Give the magnitude and direction of B at a point 2.5 m east of the wire.
Current, I=50A
Distance, r=2.5 m
Magnetic field,
B=μoI2πrB=4.0×10−6T
According to maxwell's right hand, the direction of field is upward.