Permanent magnets, magnetic materials, and magnetic needles

While conducting the test, we verified that a magnetic field exists around any magnet with closed lines of force emanating from the north pole of this magnet and entering its south pole.

The magnetic field induction lines of permanent magnets

We make sure that there is a magnetic field around any magnet, the lines of force of which are closed, they come out of the north pole of this magnet and enter its south pole.

Interaction of an electromagnet with permanent magnet

While conducting the test we have verified that the electromagnet has the properties of a magnet only when the windings have a current. In this case there are also two poles, north and south, and a normal magnetic field surrounds the electromagnet.

Interaction of an electromagnet with permanent magnet

While conducting the test we have verified that the electromagnet has the properties of a magnet only when the windings have a current. In this case there are also two poles, north and south, and a normal magnetic field surrounds the electromagnet.

Simple electric circuit

While conducting the test we verified that the circuit shall be closed and contain at least one source of electrical current for electrical current flow in a circuit. The current flow in a circuit is detected by the light bulb glowing.

Simple electric circuit

While conducting the test we verified that the circuit shall be closed and contain at least one source of electrical current for electrical current flow in a circuit. The current flow in a circuit is detected by the light bulb glowing.

Dependence of the current force on the voltage in a circuit section

While conducting the test we confirmed the Ohm’s law for a circuit section under the condition of stable resistance and verified direct proportionality of the current force in this circuit to the applied
voltage.

Dependence of the current force on the voltage in a circuit section

While conducting the test we confirmed the Ohm’s law for a circuit section under the condition of stable resistance and verified direct proportionality of the current force in this circuit to the applied
voltage.

Volt-ampere characteristics of the light bulb

While conducting the test we verified that Ohm’s law does not apply to some conductors, such as an ordinary light bulb, in the tested voltage range. In particular we detected that the graph of the light bulb volt-ampere characteristic is not linear.

Volt-ampere characteristics of the light bulb

while conducting the test we verified that Ohm’s law does not apply to some conductors, such as an ordinary light bulb, in the tested voltage range. In particular we detected that the graph of the light bulb volt-ampere characteristic is not linear.

Determining the resistance of high-resistivity conductor

While conducting the test we found out how the resistance of a circuit section, in particular, represented by a high-resistivity nichrome conductor, can be determined based on Ohm’s law using an ammeter and a voltmeter.

Determining the resistance of high-resistivity conductor

While conducting the test we found out how the resistance of a circuit section, in particular, represented by a high-resistivity nichrome conductor, can be determined based on Ohm’s law using an ammeter and a voltmeter.

Determining the resistor and thermistor resistance when heating

While conducting the test we verified the resistor resistance increases slightly when heated, while the thermistor resistance, on the contrary, decreases significantly.

Verifying the power source polarity

While conducting the test we confirmed that the power source has two different poles and the electrons run only from the negative to the positive pole, and the opposite vector from (+) to (-); is taken as the direction of the current. At the same time, LED passes current only in one direction, thus allowing to check the power source polarity.

Measuring the electromotive force and the internal resistance of the power source

While conducting the test we determined the electromotive force of the power source was determined, as well as measured its internal resistance.

Electrical energy transformation into other forms of energy

While conducting the test we confirmed that electrical energy may be transformed into other forms of energy, such as heat, light, and mechanical energy, as well as the sound waves energy.

Electrolyte and non-electrolyte substances

While conducting the test we found out that there are electrolyte substances conducting the current in water solution and non-electrolyte substances not conducting the current in water solution. As for the tested substances, clean water is a non-electrolyte, like sugar, while baking soda and copper sulfate are electrolytes, and copper sulfate is much stronger electrolyte compared with soda.

Copper deposit from CuSO 4 solution

While conducting the test we were able to verify that the anions oxidation and cations deoxidization occur at the electrodes when current is passing through the electrolyte solution. In particular, the anode destruction has been observed because of interaction with anions and atomized copper deposition at the cathode due to interaction with cations.

Testing the volt-ampere characteristics of systems CuSO 4 solution + copper/graphite electrodes

While conducting the test we made sure that the system copper (II) sulfate solution and copper electrodes; meets Ohm’s law at low current force and voltage, while the system copper (II) sulfate solution and graphite electrodes does not meet Ohm’s law.

Galvanic cell. Its electromotive force and internal resistance

While conducting the test a simple galvanic cell has been made from citric acid solution and two electrodes: copper and zinc, and its electromotive force and internal resistance (quite significant and usually exceeding 50 Ohm) have been determined.

Series conductor joint

While conducting the test we verified the laws of series conductor joints and made sure that they are implemented.

Parallel connection of conductors

While conducting the test the laws of parallel connection of conductors have been verified and the fulfillment of these laws has been confirmed.

Series and parallel connection of power sources

While conducting the test we verified that if the batteries are connected in series, the voltage in a circuit is equal to the sum of their voltages, and if the batteries are connected in parallel, the voltage in a circuit is equal to one battery voltage.

Series and parallel connection of electricity consuming units

While conducting the test we verified that if identical electricity consuming units are connected in series, the voltage at each of them is equal to the power source voltage divided by the number of units, and the voltage at each unit is equal to the power source voltage if the units are connected in parallel.

Kirchhoff’s first law verification

While conducting the test we verified that Kirchhoff’s first law applies and the sum of the positive currents flowing into the branches is equal to the sum of the negative currents flowing away from the branches.

Kirchhoff’s first law using the example of a complex circuit

While conducting the test we verified that Kirchhoff’s first law also applies to complex circuits, containing two power supply sources, six resistors and four branches.

Kirchhoff’s second law verification

While conducting the test we verified that Kirchhoff’s second law is valid in a circuit with two power sources, three resistors and one branch (within the accuracy).

Potentiometer

While conducting the test we learntlearned the principles of operation and use of a potentiometer – adjustable resistor with three terminals, one of which is movable and is used as a voltage divider.

Testing the electrical circuit with relay

While conducting the test we examined a special device – the electromagnetic relay, and have verified that the low current in this device can control circuits with much higher current, in our case, by a sequence higher current.

Simple electrical circuit with relay

While conducting the test we examined a special device – electromagnetic relay and made a simple electric circuit in which the relay controls the switching on or off of two circuits: switching on the light bulb and switching off the LED, or on the contrary – switching off the light bulb and switching on the LED.

Testing the photoresistor’s resistance change

While conducting the test the dependence of the photoresistor’s resistance on its lighting level was tested, and a markedly non-linear graph of this dependence was plotted on the basis of the data obtained.

Rectifier diode volt-ampere characteristics

While conducting the test we examined a nonlinear semiconductor device – a rectifier diode, which passes the direct current well, but only after the opening, and does not pass the reverse current within the verified voltages range.

Stabilitron volt-ampere characteristics

While conducting the test we examined a nonlinear semiconductor device – a stabilitron which conducts direct current, but only after the opening voltage; and, unlike a rectifier diode, also conducts reverse current, but only after the breakdown.

Volt-ampere characteristics of the light-emitting diode

While conducting the test we examined a nonlinear semiconductor device – a light-emitting diode, which conducts the direct current well, but only after the opening voltage, and does not conduct
the reverse current within the verified voltages range.

Bipolar NPN transistor

While conducting the test we got to know a semiconductor device, that is a bipolar NPN transistor with one electrode, in particular the base, used to control the current flowing between the other two electrodes – the emitter and the collector.

Volt-ampere characteristics of bipolar NPN transistor

While conducting the test we learned about the input and output volt-ampere characteristics of bipolar NPN transistor.

Volt-ampere characteristics of bipolar PNP transistor

While conducting the test we learned about the input and output volt-ampere characteristics of bipolar PNP transistor.

Simple current amplifier

While conducting the test we assembled a simple current amplifier and verified that it functions and indeed amplifies the input signal significantly.

Human body as current conductor

While conducting the test a circuit has been made, proving that the human body is a conductor of electrical current.

Simple light-sensing circuit

While conducting the test we assembled a simple device that responds to the photoresistor’s lighting changes by activating or deactivating the LED. For example, this such circuit can be used for informing people indoors about whether it is day or night.

Simple light detector

While conducting the test we assembled a simple light detector, which can be used for switching on the light source if the room is not lightened enough and, on the contrary, for switching off the light
bulb if the room is lightened enough.

Monitoring the temperature conditions in the room

While conducting the test a simple device was assembled, which can be used for switching on the DC motor (fan) at high indoor temperature and, on the contraryas a result, switching it off at a comfortable indoor temperature.

Logic gate “AND”

While conducting the test we examined the “AND” logic gate, assembled it from simple components, learned its operation principle and verified its truth table in practice.

Logic gate “BUF”

While conducting the test we examined the “BUF” logic gate, assembled it from simple components, learntlearned its operation principle and verified its truth table in practice.

Logic gate “NAND”

While conducting the test we examined the “NAND” logic gate, assembled it from simple components, learned its operation principle and verified its truth table in practice.

Logic gate “NOR”

While conducting the test we examined the “NOR“ logic gate, assembled it from simple components, learntlearned its operation principle and verified its truth table in practice.

Logic gate “OR”

While conducting the test we examined the “OR“ logic gate, assembled it from simple components, learned its operation principle and verified its truth table in practice.

Logic gate “NOT”

While conducting the test we examined the “NOT“ logic gate, assembled it from simple components, learned its operation principle and verified its truth table in practice.

Orsted’s experiment with a dip-needle

While conducting the test we confirmed that the magnetic field is formed around the conductor with the flowing current, and the magnetic field direction depends on the current direction in the conductor. We also verified that magnetic field around the coil is significantly stronger than magnetic field around a direct conductor.

Testing the magnetic field force generated on the coil

While conducting the test we were able to verify that magnetic field is formed around the conductor coil with the force dependent on the number of conductor turns.

Testing the magnetic field force generated on the coil with a magnetometer

While conducting the test we confirmed that magnetic field is formed around the conductor coil with the force dependent on the number of conductor turns and the current force in a circuit.

Simple AC rectifier circuit

While conducting the test we assembled a simple rectifier converting alternating current to direct current.

Simple AC multiplier circuit

While conducting the test we assembled a simple circuit of a current multiplier does not only rectify the current by converting it from AC to DC, but also almost doubles its voltage.

Electromagnetic induction

While conducting the test we verified that induction current is generated in a closed conductor being in an variable magnetic field or moving in a continuous magnetic field, i, e, the phenomenon of electromagnetic induction is observed.

Self-induction

While conducting the test we verified a self-induction phenomenon, which means that the current force change in a conductor causes its magnetic field change and generates an electromotive force in the same conductor.

Dependence of alternating current force on its frequency and voltage at the induction coil

While conducting the test we studied the dependence of the current force in the induction coil on the voltage and frequency of alternating current. Thus, we found out that the current force increases linearly with the voltage increasing at a constant frequency, and the current force decreases nonlinearly with the frequency increasing and at a constant voltage.

Series and parallel connection of induction coils

While conducting the test we studied the dependence of the current force on the voltage and frequency of alternating current in series and parallel-connected induction coils. Having compared the obtained results with the data for one coil we verified the total impedance of the circuit is equal to the sum of the series-connected coils impedances, and the total impedance of the circuit is equal to half of the impedance of one coil in parallel connection of the coils.