1. Laws of electromagnetic induction (a) conditions, (b) E.M.F., (c) direction.
2. Devices, (a) magneto, (b) dynamo: series, shunt, compound.
3. Illustrations of the laws.
Exercises
1. Under what conditions may an electric current be produced by a magnet?
2. Show how Lenz's Law, follows from the principle of conservation of energy.
3. A bar magnet is fixed upright with its north-seeking pole upward. A coil is thrust down over the magnet. What is the direction of the current induced in the coil? Explain.
4. In what two ways may a current be induced in a closed coil?
5. What method is employed in the magneto? In the dynamo?
6. What is the nature of the current produced in the armature coil of a magneto, that is, is it direct or alternating? Why?