question_answer

A coil having N turns carry a current I as shown in the figure. The magnetic field intensity at point P is [BHU 2003; CPMT 2004]

A)            \[\frac{{{\mu }_{0}}NI{{R}^{2}}}{2{{({{R}^{2}}+{{x}^{2}})}^{3/2}}}\]              

B)            \[\frac{{{\mu }_{0}}NI}{2R}\]

C)            \[\frac{{{\mu }_{0}}NI{{R}^{2}}}{{{(R+x)}^{2}}}\]     

D)            Zero