$5$a: There are four infinite parallel currents arranged in a square of side $2$L$.$

All

four currents

have the same magnitude I. Determine the direction of the

net

magnetic

field

at

point P

which

is

at

the center of the square. You should certainly include a

vector addition

dia$-$

gram as part of your solution. As you draw each individual vector, make sure you identify

which current creates each field.

$10$

points.

$2$L

b: Determine the magnitude of the net magnetic field

at

point P in terms of whatever

variables are needed.

$10$

points