question_answer

A uniform wire is bent in the form of a circle of radius R. A current I enters at A and leaves at C as shown in the figure : If the length ABC is half of the length ADC, the magnetic field at the centre O will be                                       [MP PMT 1997]

A)            Zero

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

C)            \[\frac{{{\mu }_{0}}I}{4R}\]

D)            \[\frac{{{\mu }_{0}}I}{6R}\]