question_answer

In the following arrangement as shown in figure, the magnetic field at point O is given by

A)  \[B=\frac{{{\mu }_{0}}}{4\pi }\frac{i}{a}\,(sin\,{{\theta }_{1}}+sin\,{{\theta }_{2}})\] 

B)  \[B=\frac{{{\mu }_{0}}}{4\pi }\frac{i}{a}\,(sin\,{{\phi }_{1}}+sin\,{{\phi }_{2}})\]

C)  Both of [a] and [b]

D)  None of these

Correct Answer: B

Solution :

From the given figure, magnetic field at point O is given by s \[B=\frac{{{\mu }_{0}}}{4\pi }\,\frac{i}{a}\,\,(sin\,\,{{\phi }_{1}}+sin{{\phi }_{2}})\]