Marktplatz für digitale Bildungsmedien
Electricity flowing through a wire generates a magnetic field. If this wire is twisted into a coil, the magnetic fields of the individual turns merge into a single stronger field. An iron core in the middle can intensify this effect. With this description, the video explains the construction of an electromagnet.
Georg Simon Ohm discovered that voltage and current are interdependent. This video explains electrical resistance, Ohm´s law and the relationships that can be derived from it. The influence of length, strength, and temperature of a conductor as well as the calculation of electrical resistance are further topics.
The electrical resistance is defined as the quotient of the voltage and the strength of the current flowing in a circuit. At the same time, resistance also refers to a component with which a certain resistance can be realized in an electrical circuit. The film explains both terms using understandable examples.
We take it for granted in everyday life that electricity "flows". This video explains electrical circuits and the movement of electrical load carriers within them. It also looks at conductors and insulators, at the effect of negatively and positively charged materials on one another, and at induction.
In this video, the basic functional principle of the electric motor is explained. Among other things, the structure of the rotor, the stator, and the commutator in the DC motor are clearly illustrated. The film then shows the different uses of permanent magnets and electromagnets in the electric motor.
If we perceive something as heavy, this is due to the high mass of the object with its comparatively low volume. The density of an object is defined as the ratio of its mass to its volume. The film uses a number of everyday examples to show how the mass of substances can vary greatly for the same volume.
The electrical component coil works with an interaction of electricity and magnetism. The video shows how electromagnetic induction works, i.e., the generation of electrical voltage on an electrical conductor by a changing magnetic field. The film explains inductance and Lenz´s rule and introduces the many uses of coils.
The subject of this film is the simple CCR circuit. It is explained using the example of a radio with an external loudspeaker. The first C stands for the coil, the second for the capacitor, and the R for the resistor. The film explains how the coil and capacitor can be used as filters for high and low frequencies.
Electricity flows in an electric circuit. With switches, you can interrupt this flow. The video explains how the various switches such as push-buttons, circuit breakers and sensor switches work. Various examples of the AND- and OR-switch show that an electric circuit can also be interrupted several times.
The subject of this film is electromagnetic induction. A conductor loop suspended in a magnetic field illustrates how mechanical energy can be converted into electrical energy. A brief history of electromagnetic induction is given, the AC and DC voltages are explained and areas of application in industry are shown.
Optical devices influence the course of light rays through lenses. The film shows how lenses are made in the eye and in visual aids such as glasses. The much stronger lenses of magnifying glasses and microscopes are also examined in detail. It is explained how exactly the multiple magnification is achieved.
Lorentz force describes the effect of magnetic fields on moving electrons. It acts perpendicularly to the magnet´s field lines and to the direction of the electrons. The film shows how to determine the direction of movement of the electrons using the three-finger rule and where this force is used for technical purposes.
The invention of the diode was soon followed by the development of another electrode - the triode. This was the first amplifier. These amplifiers were used extensively until the transistor almost completely replaced them. As the video shows, electron tubes are now only used in high-end guitar amplifiers.
The topic of this video is the relationship between voltage and amperage. The film introduces the units of measurement volts for electrical voltage, watts for power, joules for energy, and amperes for amperage. It explains why the higher the voltage, the lower the amperage needed for certain outputs.
Electrical engineers often use transformers. They can easily turn a low primary voltage into an unequally higher or lower secondary voltage. How this works in detail, for what purposes one needs this transformation in everyday life and what electromagnetic induction is exactly, is explained in the film.
Archimedes originally set out the law of the lever. The film shows how it has been developed since then and how it leads directly to the law of rotation. The law is explained and its practical uses demonstrated, for instance the wheel and axle which is used in ship´s rudders and many times in bicycles.
The physical term work is defined as the force exerted on a body in a certain way. In physics, a distinction is made between the work of lifting, acceleration, deformation, tension and friction, as the video explains with the help of examples from everyday life. The unit used to measure work is the joule.
This video shows how the state of motion, gravity and magnetic attraction of objects changes when different physical forces act on them. The film shows that the effects of these forces are measured in Newtons and that they are vector quantities. The law of interaction is also explained with examples.
For a temperature measurement procedure to be exact, it has to be reliable and repeatable. This films looks at different temperature measuring devices, namely the thermometer, the bimetallic thermometer, and the resistance thermometer, which depend on changeable substance properties at different temperatures.
With the colours blue, yellow and purple, all colours can be produced. This is due to subtractive colour mixing: the colours act like a filter that prevents you from still seeing the original colours. The video explains understandable how the absorption spectrum of the filter makes some colours visible.
In addition to conductors and non-conductors, there are also so-called semiconductors with regard to electrical conductivity. Using the example of silicon, the film explains how a substance can change from a non-conductor to a conductor under certain conditions. It mentions the many possible uses of semiconductors.
No other component is used as frequently in electronic devices as the transistor. This video tells the story of the component: how it was invented, how it revolutionized and drove technology, how exactly it works and what uses have been found for it over time - especially since the beginning of the digital age.
This video explains the concept of a magnetic field. It clearly describes some essential effects of magnetism and illustrates the concept of field lines. The film shows what the Earth´s magnetic field is all about, it clarifies geographical and magnetic poles and goes into the phenomenon of declination.
This film presents four common semiconductors that we use frequently in everyday life. It explains the structure and functioning of the thyristor, the triac, the photo-semiconductor, and the LED and shows examples of where they are used - such as washing machines, elevators, light switches and headlights.
The first semiconductors were discovered in passing when people wanted to make the light bulb more economical. Since then, a lot has changed about them. The film retraces this development and explains not only how the diode works, but also some important technical terms and the use of semiconductor diodes.
For a surface to reflect light, it must be very smooth. A regular reflection is given, for example, by processed glass and metal, which are used to make mirrors. The film explains the law of reflection, the creation of illusions through partial reflection, and that the mirror image is a result of our own perception.
If the curvature of a curved mirror is convex, it distorts the mirror image. If it is concave, this is also true, except that the image is also upside down. The film explains why this is so and how the laws of reflection explain it. In addition, the video shows possible applications for everyday life.