Answer:
Ratio of magnetic field will be [tex]\frac{B}{B'}=0.0055[/tex]
Explanation:
We have given radius of the loop r = 30 mm = 0.03 m
We know that magnetic field at the center of the loop is given by
[tex]B=\frac{\mu _0i}{2r}[/tex]---------eqn 1
Number of turns in the solenoid is given as n = 3 turn per mm = 3000 turn per meter
We know that magnetic field due to solenoid is given by
[tex]B'=n\mu _0i[/tex]-------------eqn 2
Now dividing eqn 1 by eqn 2
[tex]\frac{B}{B'}=\frac{\frac{\mu _0i}{2r}}{\mu _0ni}=\frac{1}{2nr}=\frac{1}{2\times 3000\times 0.03}=0.0055[/tex]