Electrodynamics and photoelectric effect

Magnetic flux linkage

the product of the number of turns on the coil and the flux through the coil

Faraday’s Law of electromagnetic induction

the emf induced is directly proportional to the rate of change of magnetic flux (flux linkage)

Lenz’s Law

• the induced current flows in a direction so as to set up a magnetic field to oppose the change in magnetic flux

Diode

a component that only allows current to flow in one direction

Threshold frequency

the minimum frequency of incident radiation at which electrons will be emitted from a particular metal

Work function

• the minimum amount of energy needed to emit an electron from the surface of a metal

Ideal transformer

• the power input into the primary coil is equal to the power output on the secondary coil

power transmission

• power is transmitted at a high voltage and a low current to minimise power loss on the transmission line

Significance of photoelectric effect

• it establishes the quantum theory and it illustrates the particle nature of light

why is a current induced in the coil?

• When the magnet spins, the coil experiences a change in magnetic flux. This induces an emf in the coil, which produces a current in the coil.

why does the coil experience a force

• the interaction of the magnetic field around the coil and the magnetic field of the magnet causes the coil to experience a force

Name the component that could be connected to convert an AC generator to a DC generator.

Bridge rectifier