a. What current is flowing in a 2.0m length of wire in the Earth's field of 55μT if it experiences a force of 10mN?
b. A 2 wire cable is suppling 100 A to a DC motor. Each wire has a 2 mm insulation layer and there is also a 2 mm separate insulation layer between the 2 wires. What is the force between the 2 conductors? Does these conductors repelled or attracted by that force?
c. Determine the m.m.f. necessary to create a flux of 0.5 Weber in a magnetic core which has a reluctance of 100 At/Wb.
d. A current balance has a 5.0 cm wide arm between the poles of a magnet. The flux density, B, between the poles is measured as 25mT. When the current is 1.5A, what is the force on the arm?
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