Problem 83PE
Integrated Concepts (a) What is the direction of the force on a wire carrying a current due east in a location where the Earth’s field is due north? Both are parallel to the ground. (b) Calculate the force per meter if the wire carries 20.0 A and the field strength is 3.00×10−5 T . (c) What diameter copper wire would have its weight supported by this force? (d) Calculate the resistance per meter and the voltage per meter needed.
Solution 83PE
a.) The direction of the magnetic force can be determined by the right hand rule-1.
According to this rule for a positive moving charge, right thumb is in the direction of velocity, fingers point in the direction of magnetic field and palm points in the direction of magnetic force.
Here direction of velocity is east so right thumb points to east and direction of magnetic field is north so fingers points up or north then palm points to outside of the page.
Hence, the direction of magnetic force is straight upwards of the page.
b.) The force per meter is 6.00 x10-4 N/m
c.) The diameter of copper wire is 94.2 x10-5 m
d.) The resistance per meter is 2.47 and voltage per meter is 49.4 V/m