Experiment för Elektricitet

Objective: Demonstrate the superposition of magnetic fields in a vacuum The absence of interference when magnetic fields are superposed in a vacuum is demonstrated using a Braun tube. This is done by observing the displacements of the focused spot on the fluorescent screen of the tube. The experiments can be extended to include alternating magnetic […]

Objective: Determining the relative permittivity of various materials Any insulating or poorly conducting material which lacks free charge carriers can act as a dielectric when an electric field passes through it. The material may be a gas, liquid or solid. The dielectric is polarised in the electric field. This polarisation can be induced (displacement) polarisation […]

Objective: Investigate the deflection of electrons by electric and magnetic fields In a Thomson tube the vertical deflection of a horizontal electron beam can be observed on a fluorescent screen. Such a deflection can be generated by a vertical electric field or by a horizontal magnetic field that is perpendicular to the direction of motion […]

Objective: Measure the electrostatic voltage as a function of the distance between the plates To increase the distance between the charged plates of a plate capacitor after removing their external conne ctions, mechanical work must be performed. This can be demonstrated by measuring the resulting increase of the voltage between the plates using an electrostatic […]

Objective: Determine the specific charge of an electron In the fine-beam tube, the path of electrons in a uniform magnetic field can be observed as a clearly delineated ray. This means that the radius of the circular path can be directly measured with a simple ruler. From the path radius r, the magnetic field B […]

Objective: Study the physical principles of the time-resolved display of electrical signals using an oscilloscope The student oscilloscope can be used to study the physical principles of the time-resolved display of electrical signals on a fluorescent screen. In a Braun tube, a focused electron beam is generated, and the point at which it falls on […]

Objective: Determine the polarity of the charge-carriers In the Perrin tube, the electron beam can be deflected into a Faraday cup by applying a homogeneous magnetic field. The charge of the electrons can be observed by connecting an electroscope to the Faraday cup, and its polarity can be determined by comparison with an electric charge […]

Objective: Measure the electric field in a plate capacitor using the electric field meter The electric field meter can be used to measure the electric field within a plate capacitor directly. In this experiment a rotating sectored disc interrupts the electrostatic flux falling on an induction plate, which forms part of a capacitor plate. The […]

Objective: Record characteristics for a thermionic triode In a thermionic triode, free electrons carry a flow of current between the heated cathode and the anode when a positive voltage is applied between the cathode and anode. This current can be controlled by applying a positive or negative voltage to an intervening grid.

Objective: Record the characteristic for a thermionic diode In a thermionic diode, free electrons carry a flow of current between the heated cathode and the anode when a positive voltage is applied between the cathode and anode. The current increases along with the voltage until a saturation point is reached. However, if the voltage is […]

Objective: Demonstrate and investigate the phenomena of interference, diffraction and polarisation using microwaves Using microwaves, many experiments can be conducted on interference, diffraction and polarisation, as an aid to understanding these phenomena for visible light. Diffracting objects and polarisation gratings can be used which possess a structure that can be seen with the unaided eye […]

Objective: Measuring the voltage induced in an induction coil If a closed conductor loop with N windings is located in a cylinder coil through which an alternating current flows, then an electrical voltage is induced by the variable magnetic flux through the conductor loop. This induction voltage is dependent on the number of windings and […]

Objective: Demonstrate the straight-line propagation of electrons in the absence of any field Straight-line propagation of electrons in the absence of a field can be demonstrated in a Maltese-cross tube by showing how the shadow of the electron beam coincides with the shadow due to a light beam. Any deviation from the straight-line propagation of […]

Objective: Determine the magnetic field generated by coils of various lengths The magnetic flux density inside a long cylindrical coil is directly proportional to the current through the coil and how close together the coil windings are, but is not dependent on the radius of the coil as long as the length of the coil […]

Objective: Measure the induced voltage in a conductor made into a loop as it moves through a magnetic field The change in magnetic flux that is needed to induce a voltage in a conductor loop can be caused by a movement of the loop. Such a situation results, for example, when a conductor loop orientated […]

Objective: Determine the value of certain resistances An arrangement in which two voltage dividers are connected in parallel and connected to the same DC voltage source can be used to obtain the values of certain resistors. The first voltage divider consists of the resistance that is to be measured along with a reference resistance, while […]

Objective: Determine the horizontal and vertical components of the earth’s magnetic field This experiment involves determining the inclination and magnitude of the earth’s magnetic field as well as its horizontal and vertical components at the point where the measurement is made. The horizontal component of the earth’s field can be found from the turning of […]

Objective: Demonstrate the electric current generated by the motion of charged droplets of water Electric current arises due to an amount of charge being transported during a given interval of time. A flow of current can be simply illustrated with the help of charged droplets of water. In order to carry out the measurement, a […]

Objective: Investigation of how the current through a coil changes over time when the DC supply is turned on and off The behaviour of a coil in a DC circuit changes as soon as the DC supply is turned on or off. The change in current is delayed by self-induction of the coil until it […]

Objective: Determining impedance in a circuit with an inductive and a capacitive reactance AC circuits with inductive and capacitive reactances show resonant behaviour. At the resonant frequency, the impedance of a series connection of an inductive and a capacitive reactance is zero, whereas the impedance of a parallel connection is infinite. This experiment examines this […]

Objective: Determine inductive impedance as a function of inductance and frequency Any change in the current through a coil induces a voltage. If an alternating current flows, an AC voltage will be induced, which is shifted in phase with respect to the current. In mathematical terms, the relationship can be expressed most easily if current, […]

Objective: Determine the AC resistance in a circuit with inductive and resistive loads In AC circuits, not only ohmic resistance needs to be taken into account but also the resistance due to inductive loads. The combination of the two may be connected in series or parallel. This has an effect on both the amplitudes and […]

Objective: Determine the electrical conductivity of copper and aluminium Electrical conductivity of a material is highly dependent on the nature of the material. It is defined as the constant of proportionality between the current density and the electric field in the material under investigation. In this experiment, four-terminal sensing is used to measure current and […]

Objective: Investigation of how the voltage across a capacitor changes over time when the capacitor is charging or discharging In a DC circuit, current only flows through a capacitor at the point in time when the power is turned on or off. The current causes the capacitor to charge up until the voltage across it […]

Objective: Measure the force on a current-carrying conductor in a magnetic field The experiment involves measuring the Lorentz force on a current-carrying copper rod suspended in a horizontal position from a pair of vertical wires (like a swing) and subjected to a magnetic field. When the current is switched on the “swing” is deflected from […]

Objective: Determine the impedance of a capacitor as a function of capacitance and frequency Any change in voltage across a capacitor gives rise to a flow of current through the component. If an AC voltage is applied, alternating current will flow which is shifted in phase with respect to the voltage. In this experiment, a […]

Objective: Determine the AC resistance in a circuit with capacitive and resistive loads In AC circuits, not only ohmic resistance needs to be taken into account but also the resistance due to capacitive loads. The combination of the two may be connected in series or parallel. This has an effect on both the amplitudes and […]

Objective: Measurement of the force exerted on a current-carrying conductor located inside a magnetic field The electric balance is based on André-Marie Ampères’ experiments on electric current. It measures the electro-dynamic force sometimes referred to as the Lorentz force on a current carrying conductor situated in a magnetic field using a balance. In this experiment […]

Objective: Demonstrate and investigate how an eddy-current brake works In a metal disc moving through a uniform magnetic field, eddy currents get induced. The uniform magnetic field exerts a force due to these currents that causes the disc to slow down.

Objective: Messung der relevanten Kennlinien eines npn-Transistors A bipolar transistor is an electronic component composed of three alternating p-doped and n-doped semiconductor layers called the base, the collector and the emitter. Depending on the sequence of the layers, the transistor may either be termed npn or pnp. The response of a bipolar transistor may be […]