State the expression for the magnitude of the magnetic field at a perpendicular…

PHYSICS · Single correct · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

State the expression for the magnitude of the magnetic field

B

at a perpendicular distance

r

from a long, straight conductor carrying current

I

in free space. (a)

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

(b)

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

(c)

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

(d)

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