Describe how the magnetic effect of a current is used in relays and loudspeakers and give examples of their application
Know that a current-carrying coil in a magnetic field may experience a turning effect and that the turning effect is increased by increasing: (a) the number of turns on the coil (b) the current (c) the strength of the magnetic field
State that the magnitude of an induced e.m.f. is affected by: (a) the rate of change of the magnetic field or the rate of cutting of magnetic field lines (b) the number of turns in a coil