Answer:
Explanation:
Given that,
current I=18A along positive x axis
Magnetic force per length is given as 0.27N/m, acts on negative y axis
F/L=0.27N/m
Magnetic field and direction?
a. The force in magnetic field is given as
F=iLB
Then,
F/L=iB
Since F/L is 0.27N/m and I=18A
So, 0.27=18B
B=0.27/18
B=0.015T
B=15mT
Direction, using the left hand rule
The current is point in positive x and the force motion act in negative direction,
F=L(i×B)
Note rules of cross produce
i×j=k. , j×i=-k
j×k=i. , k×j=-i
k×i=j. , i×k=-j. .....equation 1
Now applying this to force formula
F=L(i × B), where L is constant
-j=i×B
So comparing this to evaluation 1, this shows that B must k
For this to be negative, B must be k
I.e positive z axis
So the direction of the magnetic field is positive z axis
