Question

A long wire carries a current of 25.9 A in a direction 58o north of an easterly 169 mT magnetic field. What is the magnitude of the force, in the unit newton, on each centimeter of wire?

Answer 1

Concept - The force on the current carrying wire kept in a magnetic field B ,of length L , carrying current i is given by the following formula-

where , is the angle between the wire and the field .

Solution - in the question it is given that - B = 169 mT = 169 10-3 T , i = 25.9 A ,   = 580 ,
to find that = force per unit length = F / L = ?

putting all the given value in the above formula giives-

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• F /L = 3.712 10-2 N / cm