Physics

Problem

An infinitely long straight conductor carries a steady current

I

. a. (i) State Ampère’s circuital law in words as well as in mathematical form. b. (ii) Derive an expression for the magnitude of the magnetic field

B

at a point located at a perpendicular distance

r

from the axis of the conductor. c. (iii) Using your result, calculate the value of

B

at a point

2\,\text{cm}

from a wire that carries a current of

20\,\text{A}

. Express the answer in tesla.