### Electricity and electromagnetism videos to buy

The details of the video tutorials available to buy on electricity and electromagnetism are given below. At the bottom of the page is an example video.

Electric current and Kirchhoff's first Law  3m 50s    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
An explanation of the nature of electric current and the meaning of Kirchhoff's first law.

Drift velocity 4m
Illustrating the meaning of drift velocity and how the value can be calculated.

Explaining Potential Difference 2m    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
An explanation of the meaning of PD in relation to the power of an electric current.

Potential dividers. 3m 30s
Using practical examples to show the practical use of potential dividers with simple calculations.

An explanation of EMF and internal resistance.2m 30s    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
Explaining the relationship between external and internal resistance and the power dissipated in each.

Measuring EMF and internal resistance.3m 20s
A video of an experiment to measure both with explanation and calculations.

Explaining resistance 2m 25s    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
A reminder of the concept and method of measuring.

Ohm's Law 3m 20s    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
An explanation of the law with experimental verification.

Resistors in parallel 2m 45s    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
An explanation of the relationship between the individual resistance values and the total resistance.

Resistance and temperature 3m    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
An explanation of the effect of temperature change on a metal filament with I/PD characteristics

Diode characteristics 3m    (In GCSE, 14 to 16 years, collection also suitable for A level introduction)
A reminder of the function of a diode with a derivation of the I/PD characteristic graph.

Measuring and calculating resistivity and conductivity 8m
Demonstrating the measurements of diameter, length and resistance needed to accurately calculate the resistivity including an explanation of a method to assess the possible errors.

How a capacitor works 6m
The video uses demonstrations and animations to show how a capacitor works and highlights this by making a simple capacitor and using it.

Capacitors in Series and Parallel and the Time Constant  5m

Demonstrating circuits with diagrams, calculations and in practice, calculating the total value of two capacitors in series and in parallel and measuring the time constant of capacitor charge/discharge showing the results and graphs.

Magnetic fields, domains, Maxwell's rule and permeability  8 minutes    (Some of this is in GCSE, 14 to 16 years, collection also suitable for A level introduction)
There are three parts to this video lesson:
What are the causes of magnetism- magnetic domains
The shapes of magnetic fields around permanent magnets, wires and coils; Maxwell's corkscrew rule
Magnetic permeability.

What are magnetic flux and flux density? 3 minutes
An explanation explained through video of experiments diagrams and animations of magnetic flux in terms of fundamental units, followed by a definition of flux density.

Measuring magnetic flux density  4 minutes
The video of an experiment to measure flux density is explained together with the calculations

Fleming's left hand rule 3 minutes
Showing the interaction of the magnetic field and the consequent direction of the force.

Charged particles in a magnetic field  4 minutes
The size and direction of the force on charged particles fired into a magnetic field causing them to take a circular path. Explanation of the calculation of charge/mass ratio

Electromagnetic induction, Faraday's Law, the alternator, Lenz's Law       12 minutes
This tutorial sets out to explain Faraday's Law with video and animated demonstration of a single wire and a coil cutting through a magnetic field as well as the mutual induction between two coils. The ideas are applied to the alternator, with clear diagrams of the construction and animated description of the generation of an alternating EMF. Lenz's Law is illustrated via the well known floating ring demonstration.

Transformers  12 minutes    in four parts:   (Some of this is suitable for GCSE, 14 to 16 years, collection also suitable for A level introduction)

·      What transformers are and the way they work in terms of electromagnetic induction using demonstrations, diagrams and explanations.

·      The structure of a transformer and the calculation of voltage change.

·      An explanation of the laminated core including an explanation of eddy currents with a demonstration.

·      The use of transformers in power distribution including a worked example of comparative power loss.