A single circular loop of radius carries a steady current
PHYSICS · Multi-part · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism
Problem
A single circular loop of radius R carries a steady current I. Point P lies on the axis of the loop at a distance x from its centre.
(i) State the fundamental law that relates the magnetic field produced by an element of a current-carrying conductor to the position vector of the point of observation.
(ii) Starting from the law stated in part (i), obtain an expression for the magnitude of the magnetic field B at point P in terms of μ0,I,R and x. Clearly indicate the direction of B.
(iii) Hence obtain the value of B at the centre of the loop and also for points far away on the axis (x≫R). Comment on how B depends on x in the far-field region.
(iv) How does the expression in part (ii) get modified if the loop is replaced by a closely wound coil of N turns carrying the same current I? Write the new expression without derivation.