Which of the following expressions gives the magnitude of the magnetic field at a…

PHYSICS · Single correct · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current

Problem

Which of the following expressions gives the magnitude of the magnetic field

B

at a perpendicular distance

r

from a very long straight conductor carrying a steady current

I

? (a)

B = \dfrac{\mu_0 I}{\pi r}

(b)

B = \dfrac{\mu_0 I}{2 r}

(c)

B = \dfrac{\mu_0 I}{4\pi r}

(d)

B = \dfrac{\mu_0 I}{2\pi r}