A long wire carrying current I is bent in the form of a circle as shown in the figure.
The $\vec{B}$ at point O is:
Answer & explanation
Correct answer: option 4
Magnetic field due to straight wire is $ B_1 = \frac{\mu_0 I}{2\pi r}$
Magnetic field due to circular wire is $ B_ 2= \frac{\mu_0 I}{2 r}$
$ B = B_1 + B_2 = \frac {\mu_0}{4\pi} \frac{2I}{r}(1+\pi)$ Perpendicularly Inward