Secondary Catalogue

In this episode, we look at how electrical equipment is designed to use the right amount of current for the voltage supply that it's designed for. After a brief recap on electric current, we look at what voltage is and how it is measured. we then look at the concept of resistance. At a simple level, some materials are conductors and some materials are insulators, but not all conductors conduct equally well. The amount of current that flows in a household appliance depends on the appliance's resistance Show Less

In the second episode, we examine how lights, switches, and other electrical devices are all connected either in "series" or in "parallel" with each other. How do they wire up the lights in your house so that in some rooms the light switch turns on only one light but in other rooms the light switch switches on two (or more) lights? And how is everything wired up so as to allow us to turn the lights on and off in different rooms independently of one another. Well, don't wait at the terminal, jump on board. Show Less

In episode three, we take a look at what electric current is (it's basically the flow of electrons through a wire) and at how electric current is measured. We then examine the different ways that electric current flows in series and parallel circuits. Show Less

This programme is about seawater. It is the most important liquid on Earth, not only from its sheer volume, but also because it has remarkable qualities. A few of them, like buoyancy, are common to all liquids - but seawater is also the cradle of life. Three key factors of water underpin life in the sea: water’s dissolving power, its tendency to keep a stable temperature, and its transparency to light. This programme explains the mechanisms and the outcomes of these key facts—and other things—that make seawater both weird and wonderful. Show Less

A body is said to be in a state of rest if its position does not change with respect to a reference point with the passage of time, and a body is said to be in a state of motion if its position changes with respect to a reference point with the passage of time. Show Less

In an inclined plane, the mechanical advantage is the length of the slope divided by the height of the inclined plane. The mechanical advantage of a wedge is determined by dividing the length of the wedge by its width. The mechanical advantage of a screw is the ratio of the circumference of the screw to the distance the screw advances during each revolution. Show Less

A lever is a rigid bar that is free to rotate or pivot on a fixed point called a fulcrum. In the case of a lever, we increase the input distance. The ideal mechanical advantage is calculated by dividing the distance from the fulcrum to the input force by the distance from the fulcrum to the output force. Show Less

The convex mirror is used in rear-view mirrors in vehicles because it forms an erect and smaller image of the scene behind the vehicles. Convex mirrors are used in street lights and in shops, big supermarkets, and other places as anti - theft devices.They are also useful in parking vehicles and in removing blind spots. Show Less

In the final episode, 'Heat and the Human Body', we look at the brilliant systems within our bodies that allow us to maintain a more-or-less constant body temperature regardless of the weather conditions. Sweating, shivering, pumping more blood to some parts of our bodies than to other parts, curling up into a ball, and spreading out your arms and legs all play their part in keeping our bodies at the right temperature! But what happens when we reach our limits? Show Less