Consider a circular current-carrying loop of radius R in the x-y plane with center at origin. Consider the line integral

taken along z-axis.


(a) Show that monotonically increases with L.


(b) Use an appropriate Amperian loop to show that .







Now from the diagram


L=R tanθ



Putting it back to the equation,




eq.1


a) As sinθ always increases from 0 to π/2. Hence is also monotonically increasing function.


b)





When


So,


c)From eq1.



Now


So,


,



d) circular> square.


We can further find square using the magnetic induction due to a wire.


But as there is no term representing the characteristics of the loop in .


So it remains the same.


1