Magnet

2a. In a dynamo, a magnet is surrounded by an iron core wrapped in wire. As the magnet rotates (from the motion of a bike wheel for instance), its field lines cut the iron core. This induces a voltage in the wire, and if the wire is part of a circuit, it is a current.

b. If the magnet in the dynamo isn't moving, no magnetic field lines are being, and consequently no current is being induced.

c. A generator that produces alternating current is called an alternator.

d. Alternating current features a current that goes in opposite directions with a certain frequency, e.g. 50Hz in UK Mains. As a result, on a cathode-ray oscilloscope, it produces a graph that resembles a sine curve. Direct current is always at the same voltage; hence it resembles a straight line on a cathode-ray oscilloscope.

e. The statement means that UK Mains supply completes 50 complete cycles of current each second.

2a. In a dynamo, a magnet is surrounded by an iron core wrapped in wire. As the magnet rotates (from the motion of a bike wheel for instance), its field lines cut the iron core. This induces a voltage in the