1) A twelve turn coil 10 cm in diameter has its axis parallel to a magnetic field of 0.5 T which is produced by a nearby electromagnet. The current in the electromagnet is cut off, and as the field collapses, an average emf of 8 V is induced in the coil. What was the length of time required for the field to disappear?
2) The cables that connect the starting motor of a car with its battery are 1 cm apart for a distance of 40 cm. Find the force between the cables when the current in them is 300A.