Physics

Diodes as rectifiers

Principle

It can be assumed that the students know about the valve action of a diode and also have a knowledge of the basic properties of alternating currents (constant change in magnitude and periodical change in the direction of the current). They can t ...

Diodes as rectifiers

Principle

A diode only allows current to flow in one direction and blocks the flow of itin the other direction. So the current can flow only during a half wave through a diode in an alternating current circuit.

Tasks

Measure ...

The characteristic curve of a silicon diode

Principle

Characteristic curves provide professionals with information on the behaviour of electrical components. Each type of component has its own typical characteristic curve. The students are to learn this in connection with this experiment, in which they t ...

Properties of solar cells - dependence on the illuminance

Principle

Solar cells play a substantial role in the development of alternative, non-fossil sources of energy. They convert light energy directly into electrical energy. 

In this experiment, the influence of the illumination on the shor ...

Current-voltage characteristic of a solar cell

Principle

The maximum utilisable power of a solar cell is dependent on the intensity of the incident light. Characteristic current-voltage curves are prepared under various illuminations.

Task

How does a load change the ...

The NPN transistor

Principle

This experiment should impart the knowledge, that a collector current only flows through a transistor when the correct polarity of the collector voltage is chosen and a base voltage of correct polarity is applied. For an npn transistor, both the colle ...

The transistor as a direct current amplifier

Principle

In a transistor, a small change in the base current causes a large change in the collector current. In this experiment, the relationship between the collector current and the base current is examined, and the control characteristic graph pl ...

The current-voltage characteristic of an NPN transistor

Principle

The knowledge of the characteristics of a transistor is a prerequisite for a deeper understanding of the processes related to a transistor amplifying or switching stage. Of the four characteristics (the output, control, input and reverse voltage ...

The transistor as a switch

Principle

The development of computer engineering and the increasing digitalisation in the transmitting and processing of information are accompanied by an increasing use of transistors for switching functions.

This experiment is designed to demonstra ...

The transistor time-delay switch

Principle

Delay circuits are presently in wide usage for delaying the switching on of alarm systems. Their working principle is based on the time involved in the charging and discharging of capacitors, which the students have already dealt with. An increasing o ...

Conversion of electrical energy into thermal energy

Principle

The heating and lighting effects of electric current are well known to the students from everyday life, and they have already experimented with filament lamps and utilised their illuminating, or lighting, effect as a measure of the strength of electri ...

Conversion of electrical energy into mechanical energy

Principle

In the first part of the experiment, the qualitative observation of the energy conversion process is of primary interest. It is a common everyday occurrence to see a motor lifting a load. The distinctive feature of this setup is, that the directly sub ...

Conductivity of aqueous solutions of electrolytes

Principle

Salts, acids and bases are electrolytes. In pure form they do not (or hardly) conduct electric current, because in this condition they have no (or only extemely few) freely mobile electrons. In water, the dissolved electrolyte divides (dissociates) in ...

Connection between voltage and current in conductive proces-ses in liquids

Principle

After the students have recognised that there are also conducting liquids, namely aqueous solutions of electrolytes, the question whether Ohm's Law is also valid for them is to be answered.
The experimental results affirm that this is true ...

Electrolysis

Principle

The students know that metallic conductors do not change chemically when current passes through them. This experiment should bring them to the realisation, that the chemical composition of a liquid conductor does change when electrical current passes ...