In the SI system the unit of electric current is defined with the help of the…
PHYSICS · Multi-part · AP · Physics C: Electricity and Magnetism · Magnetic Fields and Electromagnetism · Magnetic Fields and Electromagnetism
Problem
In the SI system the unit of electric current is defined with the help of the mechanical force between two parallel conductors.
(i) Using the appropriate relation, calculate the magnitude of the force per unit length between two long, straight, parallel conductors that are 1.0m apart in vacuum and carry equal currents of 1.0A in the same direction.
(ii) Show that the numerical value obtained in part (i) is 2.0×10−7N m−1.
(iii) Write the statement that uses this result to define one ampere in the International System of Units.