Physics

Problem

The SI unit for current is the Ampere, or Amp. a. How is an Amp defined? b. Show that the definition of an Amp is consistent with the equation

\frac{F}{l} = \mu_0 \frac{I_1 I_2}{2\pi r} ,

where

\frac{F}{l}

is the force per unit length of the wires,

\mu_0

the permeability of free space (

\mu_0 = 4\pi \times 10^{-7} \text{ N A}^{-2}

I_1

and

I_2

are the two currents, and

r

is the distance between the two wires. c. Calculate the force per unit length experienced by two conductors in a vacuum, each carrying a current of 1 A separated by a distance of 0.25 m. d. If the direction of the currents in part i is the same, what will be the effect of the force between the two conductors? What if the currents are in opposite directions?

Browse the problem library