Question

Q. 1. Calculate the magnetic field B at a distance 0.1 m from a long straight
wire carrying a current of 5A.​

Answer 1

Answer:

Here, I=5A;1=0.1m;

Mass per unit length of the wire

λ=3×10−3kgm−1

Therefore, weight of the wire,

mg=3×10−3×0.1×9.8=2.94×10−3N

Let B be the strength of the magnetic field applied. 

F=BIl=B×5×0.1=0.5B

In equilibrium,

F=mg

∴0.5B=2.94×10−3

B=0.52.94×10−3=5.88×10−3T