Question

4. (100 points) Two thin coils of radius R = 3 cm are d = 20 cm apart and concentric with a common axis. Both coils contain 10 turns of wire with a conventional current of I = 2 A that runs counter-clockwise as viewed from the right side (see the figure). Q O 2 A 2 A 10 turns 10 turns Side view 20 cm A. What is the magnitude and direction of the magnetic field on the axis, halfway between the two loops, without making the approximation z >> r? (For comparison, remember that the horizontal component of magnetic field in the United States is about 2 x 10-5 tesla) B. In this situation, the observation location is not very far from either coil. Calculate the magnitude of the magnetic field at the same location, using the 1/z3 approximation. The percent error of an approximate result can be found by 100*abs(1-(approx)/(exact)). What percentage error results if you calculate the magnetic field using the approximate formula for a current loop instead of the exact formula? C. What is the magnitude and direction of the magnetic field midway between the two coils if the current in the right loop is reversed to run clockwise? 3 cm

Answer 1

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