Help on Tele2, tariffs, questions

DepEducation and Youth of Ugra
budgetary institution of vocational education
Khanty-Mansiysk Autonomous Okrug - Ugra
"Megion Polytechnic College"
(BU "Megion Polytechnic College")

METHODOLOGICAL DEVELOPMENT
ELECTRICAL ENGINEERING LESSON
ON THE TOPIC: “Alternating electric current”

Developed by a teacher
physicists A.M. Magomedov
Megion, 2015
Lesson topic: “Alternating electric current.”

Lesson objectives:
Educational:
To form an understanding of alternating current among students. Consider the main features of active resistance. Reveal the basic concepts of the topic.
Developmental:
To develop in students the ability to apply acquired knowledge about alternating current in practical application in everyday life, technology and industrial practice; develop interest in knowledge, the ability to analyze, generalize, and highlight the main thing.
Educational:
To instill respect for science as a force that transforms society and people based on innovative technologies. To instill in students a sense of self-demandingness and discipline. Expand the scope of the students’ surrounding world.
Lesson type: learning new knowledge based on previously studied material.
Methods: explanation by the teacher using a computer; informational and illustrative, survey of students, work with reference notes, tests.
Lesson equipment: computer, multimedia projector, reference notes, presentation, test tasks, textbooks. Statement:
How would our planet live?
How would people live on it?
Without heat, magnet, light
And electric rays?
Adam Mickiewicz
Interdisciplinary connections: mathematics - finding the derivative, trigonometric functions; equipment – ​​mechanical equipment; history – industry of the 9th century; intra-subject communication - laws of direct current, magnetic field, electromagnetic induction. LESSON PLAN

2.Updating basic knowledge.
(Reproduction of the main provisions of the material studied in previous lessons)



6. Summing up the lesson.

7. Homework:
§ 31, 32; G.Ya.Myakishev, B.B. Bukhovtsev “PHYSICS – 11”, p. 102 exercise 4 task No. 5.
1. “New modern types of generators.”

DURING THE CLASSES
1. Organizational moment (announcement of the topic, tasks and goals of the lesson, psychological preparation of students for the lesson).
This lesson is devoted to forced electromagnetic oscillations and alternating electric current. You will learn,
- how can you get the variable EMF and
- what relationships exist between current and voltage in alternating current circuits,
- what is the difference between the effective and amplitude values ​​of current and voltage.
Slide 1
Slide 2
Slide 3
2.Updating basic knowledge
He brings warmth and light to everyone
There is no one more generous than him in the world!
To towns, villages, cities
He comes by wire! (electricity)
Reproduction of the main provisions of the material studied in previous lessons:
1. What is called electric current?
2. What current is called constant?
3. What relationship exists between alternating electric and magnetic fields?
4. What is the phenomenon of electromagnetic induction?
5. What electromagnetic oscillations are called forced?
6. Formulate Ohm's law for a section of the circuit.
3.Explanation of new material.
In electrostatic machines, galvanic cells, and batteries, the EMF did not change its direction over time. In such a circuit, the current flowed all the time, without changing either magnitude or direction, and therefore was called constant.
Electrical energy has an undeniable advantage over all other types of energy. It can be transmitted by wire over vast distances with relatively low losses and conveniently distributed among consumers. The main thing is that this energy, with the help of fairly simple devices, can be easily converted into any other forms: mechanical, internal, light energy, etc. You are future technologists and in practice you will see many different devices in which electrical energy is converted into other types of energy. Examples of such equipment are: potato peeler, electric meat grinder, bread slicer...
Slide 4
All this equipment and much more is included in a circuit in which alternating electric current flows.
Alternating current is generated in power plants. A variable EMF is born, which repeatedly and continuously changes its magnitude and direction. This happens in generators - these are machines in which EMF arises as a result of the phenomenon of electromagnetic induction.
Alternating current has an advantage over direct current:
voltage and current can be converted within a very wide range, transformed with almost no loss of energy.
So what is alternating electric current?
Slide 5
Alternating electric current is produced in alternating current generators.
Let's consider the principle of operation of the generator:
Slide 6
On this slide we saw that alternating current can arise when there is an alternating EMF in the circuit.
Slide 7
Slide 8
The figure shows the simplest circuit of an alternating current generator.
Historical background (student message)
We will study the design of generators in more detail in the following lessons.
Slide 9
Slide 10
Slide 11
Slide 12
Slide 13
4. Consolidation and generalization of new material.
(Quality check, consolidation and generalization of what has been learned, conclusions.)
Slide 14
So, what did we learn in class today:
- what is alternating electric current alternating electric current?
- What phenomenon is the basis for obtaining an alternating EMF in a circuit?
- what is the phase difference between the current and voltage oscillations across the active resistance?
- how do the effective values ​​of alternating current and voltage compare with the values ​​of direct current and voltage?
- How is power determined in an alternating current circuit?
Performing a test task followed by self-test)Slide 15
The solution of the problem
Slide 16, 17
6. Summing up the lesson.
(Giving marks and their comments.)
Slide 18
7. Homework: § 31, 32; G.Ya.Myakishev, B.B. Bukhovtsev “PHYSICS – 11”.
p. 102 exercise 4 task No. 5.
Prepare abstracts on the following topics:
1. “New modern types of generators”
2. “Equipment for public catering establishments in which electrical energy is converted into other types of energy.”

Methodological development of a physics lesson. Grade 11

KGKOU "Evening (shift) secondary school No. 1"

Topic: Electrical measuring instruments

The topic of the lesson is included in the work program in physics for evening (shift) secondary schools and correspondence education in the 11th grade. Students need to know: the structure, principle of operation and practical application of electrical measuring instruments (hereinafter referred to as EIP). This topic is being studied for the purpose that many students are engaged in industrial activities and study at a vocational school in correctional colonies. Since the age of the contingent is 25-30 years, the issue studied in evening school should have a polytechnic focus in order to contribute to the creation of a general technical minimum of knowledge and skills, on the basis of which they could apply their knowledge.

The purpose of the lesson :

Forming in students an understanding of the structure and principle of operation of EIP based on the action of a magnetic field on a current-carrying conductor

Tasks:

Educational: expand knowledge on studying instruments; develop skills and abilities to apply acquired knowledge in practice; teach how to read instrument scales; be able to explain the structure and operating principle of devices

Educational: develop the ability to analyze the task conditions; summarize the studied material, draw conclusions when performing practical work; evaluate classmates' answers; continue to develop speech using physical and technical terms

Educational: enrich knowledge based on the spirit of competition; cultivate goodwill towards each other; evaluate your answers and the answers of other students; treat materials and equipment with care; instill an interest in physics and technology.

Lesson type: combined

To achieve these goals, the following material and technical equipment of the lesson is provided:

Technical equipment

EIP for various systems and purposes

Magnetoelectric machine

Tripod with ring

Arc magnet

Wire coil

Key

Speaker

Connecting wires

Posters

"Electromagnetic system. Magnetoelectric system"

“Magnetic field electric field. Ampere's power"

Handout

Work card

2. Standard answers

3. Question cards

4. Cue cards

During the classes:

I . Organizational stage of the lesson.

1. Checking the availability of students (report of the duty officer)

2. Students’ readiness for the lesson (availability of pens, notebooks and equipment necessary for the lesson)

II . Lesson stage. Repetition of previously studied material

is conducted through a quiz on the topic “Magnetic field of electric current. Ampere's power"

Quiz purpose: Check students' understanding of the previous topic. Learn to give clear and complete answers to questions asked.

Quiz progress: the class is divided into two teams of 6-7 people, who independently choose the name of the teams.

The purpose of the quiz is to restore previously studied material in a spirit of competition and involves focusing on the creative beginning of the lesson. It is proposed to answer questions with the ability to choose solutions to problems based on hint cards and a list of questions (see Appendix No. 2,3,6). Each team member is responsible for the decision he makes, since he is a subject of the team, where the interdependence of the results of teamwork is strong. The student answers based on the posters and his own life experiences. The teams are given task cards and the procedure for conducting the quiz is explained. (see Appendix No. 1)

Appendix No. 1

Questions for teams

Team#1

In what cases does a magnetic field occur?

What is the ampere force modulus?

Units of force, magnetic induction, current and voltage

Team#2

Formulate a rule for determining the direction of the Ampere force.

Explain the effect of a magnetic field on a conductor (turn) with current

Do magnetic fields interact with each other?

Appendix No. 2

F=- kxF= G

F= B.I.

F=kF=ma

Appendix No. 6

Tesla

Newton

Watt

Joule

Ampere

Farad

Pascal

Pendant

Volt

Appendix No. 3

III . Indicative and motivational stage of the lesson

Based on the results of the quiz, the goals and objectives of the lesson are set. At this stage, the main task is to ensure that the students themselves set goals and objectives for the further direction of studying EIP. This technique helps to activate their existing knowledge on these issues, helps to awaken interest in the topic being studied, motivates cognitive activity. The most important thing is that these goals and objectives are personally significant. When setting up the motivational and orientational aspect, I highlight the practical orientation of the study of EIP.

III . Lesson stage. Learning new material

Students are asked educational questions:

The design and principle of operation of electromagnetic system devices, their advantages and disadvantages

The design and principle of operation of magnetoelectric system devices, their advantages and disadvantages

Symbols on EIP scales

To implement these issues, I use various forms of communication aimed at using the content of the subjective experience of each student, as well as between teams in the “student-teacher” and “student-class” dialogue. During an in-depth study of the topic material, it is proposed to solve the problem of choice: compare the devices of these systems yourself, determine their advantages and disadvantages. During the lesson, supporting expressions are written down in a notebook. The topic material is presented using posters, demonstration and laboratory equipment, which allows you to intensify mental activity. This stage takes a few minutes; students are involved in dialogue, drawing on their knowledge.

V . Operational and executive stage of the lesson

At this stage of the lesson, students consolidate their acquired knowledge by performing practical work based on EIP. To complete this task, students are asked to fill out work cards with 9 questions (see Appendix No. 4), studying devices of various systems and purposes. In this task, students themselves choose the form of the report - verbal or graphic. After the time has passed, the teams exchange work and perform mutual control using standards (see Appendix No. 5). This makes it possible to allow students to evaluate the work of their classmates without restraining their activity. To relieve stress-forming factors during practical work and to create a friendly atmosphere, the lesson can be accompanied by soft music “The Best Instrumental Hits”.

Appendix No. 5

Response standard

Student's name

Class

VI . Problem-situational

The task of this stage is to state the problem, find ways to solve it, and formulate a conclusion. It takes 3-4 minutes to solve this problem. During this time, the counting commission calculates the number of points for each team. Two questions are proposed:

What other devices use the Ampere force?

Why do some instruments have a mirror scale, while others do not?

Asking these questions makes it possible, based on the knowledge and experience gained, to choose a creative answer. The student himself looks for a way to achieve the result. This allows theoretical knowledge to be transferred to practical application (equipment) and thereby ensures an understanding of the meaning of the concepts being studied.

VII . Reflective-evaluative

Task: Summarize the knowledge and skills acquired in the lesson; assess the level of assimilation; analyze the results of individual and group work; attention to the process of completing the task. At this stage, the results of the quiz and practical work are summed up with an analysis of the grades and number of points scored by each team. The originality of the answers and rationality of presentation are also taken into account. The results of practical work showed a good understanding of the lesson topic. When summing up the lesson, students independently drew conclusions and pointed to the implementation of their goals and objectives.

The role of the teacher in this lesson was to involve students in active mental and cognitive activity through an active, creative and personal position; treating the student as a subject of his own learning activity and creating a comfortable environment in the classroom.

Methodological development of a physics lesson « Electrical measuring instruments"

Subject: "Electrical measuring instruments"

Lesson objectives:

Educational :

review with students the design of electrical measuring instruments;

repeat the concept of the Lorentz force, determine on what quantities it depends;

repeat the left hand rule; determining the direction of the Lorentz force vector using the left-hand rule

experimentally observe the effect of the Lorentz force;

teach how to apply this knowledge when solving problems.

Developmental :

promote the development of cognitive interest of students through observation of the action of the Lorentz force.

to form in students an idea of ​​the practical use of laws and theories; The effect of a magnetic field on a current-carrying frame is used in electrical measuring instruments.

Educational :

to instill in students discipline, attention, and accuracy when taking notes in notebooks;

to cultivate in students patience, willpower, and diligence in solving problems;

contribute to the formation of the scientific worldview of students;

Lesson type: Combined

Lesson equipment:

Teacher's workstation

Strip magnet, ammeter, voltmeter, multimeter, resistor, connecting wires, switch (key), galvanometer.

During the classes

Organizing time

Hello guys. Sit down. Who is absent today?

In today's lesson we will check the D/Z, repeat the material from the previous lesson, Let's study a new topic.

Checking homework.

1. What is the induction of a magnetic field in which a conductor with an active part length of 5 cm is acted upon byis the force 50 mN? The current strength in the conductor is 25 A. Conductorlocated perpendicular to the magnetic field induction.

2. With what force does a magnetic field of induction 10 mT act on a conductor in which the current strength is 50 A, if the length of the active part

3. Frontal survey questions:

What is the magnitude of the magnetic induction vector?

In what units is magnetic induction measured?

Give a definition of the concept of magnetic induction lines.

What is the characteristic feature of magnetic induction lines?

Why do the induction lines of the magnetic field created by a current-carrying coil have almost the same configuration as the induction lines of a permanent strip magnet?

Which pole of a magnet is called the north pole? southern?

Why does a magnetic field act on a magnetic needle?

Formulate Ampere's law. Write down its mathematical expression.

How is the Ampere force oriented relative to the direction of the current and the magnetic induction vector?

Formulate the left-hand rule. How to determine the direction of the Ampere force using the left-hand rule. (answer on the board)

Obtaining the formula for the Ampere force and the Lorentz force (the answer is on the board)

Evaluating student responses.

Explanation of a new topic.

The topic of our lesson“Electrical measuring instruments. The effect of a magnetic field on a moving charge. Lorentz force" Write it down.

Conversation. Orienting action magicianfilament field on a current-carrying circuit is used in electricalmeasuring instruments of the magnetoelectric system - ammeters and voltmeters.

. Magnetic measuring deviceThe electrical system is designed followingblowing way. Onlightweight aluminum frame2 straight charcoal shape with attached arrow towards it 4 the coil is wound.The frame is fixed on two axle shafts00". It is held in the equilibrium position by two thin spiral springs 3. Elastic forces from one hundredspring return armsthe carcass to the equilibrium position, aboutproportional to the angle of deflection of the arrowski from the equilibrium position. Kathe carcass is placed between the polespermanent magnetM from the tip kami of a special shape. Insidethe coil is located in a soft iron cylinder1. Such a designtion provides radialcontrol of magnetic induction lines in the area where the coil turns are located. As a resulttate at any position of the coilthe forces acting on it from the magnetic field are maximumand at constant current strength is constantus. Vectors And - depictforces acting on the coil from the magnetic field and turning it. The current-carrying coil rotates until the elastic forces from the spring balance the forces acting on the frame from the magnetic field. By doubling the current, we find that the needle rotates through an angle twice as large, etc. This happens because the forces acting on the coil from the magnetic field are directly proportional to the current:F m ~ I . Thanks to this, you can determine the current strength by the angle of rotation of the coil if you calibrate the device. To do this, you need to establish which angles to turnand the arrows correspond to the known onescurrent values.

The same device can measure voltage. To do this, you need to calibrate the deviceso that the angle of rotation of the arrowcorresponded to certain voltage values. In addition, the resistance of the voltmeter must be much greater than the resistance of the ammeter.

The teacher demonstrates an ammeter and a voltmeter to students.

Be sure to look inside the measuring device and find all the elements of its structure that were discussed.

Students approach the teacher’s table and examine the instruments.

Consolidation of knowledge.

How does a magnetoelectric system measuring device work?

Why do the magnetic forces acting on the conductors of the device coil do not depend on the angle of rotation of the coil?

What keeps the frame from rotating in a magnetic field?

How is an ammeter different from a voltmeter?

Additional material.

Electrical measuring instruments are used in industry, energy, science, and everyday life. Electrical measuring instruments are classified according to different criteria.

For example, according tounits of measured quantities . This can be seen on the scale of the device, where there is a Latin letter (A, V, W...) or the full name is indicated.

The second important feature of devices istype of current: direct or alternating .

The third distinguishing feature isaccuracy class , starting from 0.05 to 4.

The accuracy class demonstrates the absolute accuracy of the device and its basic measurement error. During operation, the reliability and ergonomics of the devices play a decisive role.

The internal structure of the devices differs by type of system. There is a class of deviceselectrostatic system: electrometers, electrostatic voltmeters.

Device classmagnetoelectric system, where magnet interaction is used

1. Induction of a uniform magnetic fieldB = 0.3 Tesla directed in the positive axis directionX . Find the magnitude and direction of the Lorentz force acting on a proton moving in the positive direction of the Y axis with speedv = 5 10 6 m/s (proton charge e+ = 1.6 10 -19 C).

Lesson summary.

The effect of a magnetic field on an electric current is used in electrical measuring instruments. They represent a class of devices used to measure quantities: current, voltage, frequency, capacitance, resistance, inductance...

Electrical measuring instruments are used in industry, energy, science, and everyday life.Announcement of grades

Homework.

§ 22; Notebook entries, No. 837, 838 (Rom.)

Reflection.

Lab 1
Subject: Electrical instruments and measurements.

Goal of the work: Study of electrical measuring instruments used in laboratory work performed at the stand.

Progress:
1.1 Study of the passport characteristics of pointer experimental devices.
Table 1 - Characteristics of electrical measuring instruments.
Name of devices Multimeter
Measuring mechanism system Electromagnetic
Measurement limit 100
Number of scale divisions 100
Division value 1
Minimum measured value 1
Accuracy class 1
Permissible maximum absolute error 1%
Type of current: Direct and alternating
Normal scale position Horizontal
Other characteristics Portable
1.2 Get acquainted with the front panel of the multimeter. When taking measurements in electrical circuits, digital multimeters are widely used - combined digital measuring instruments that allow you to measure direct and alternating voltage, direct alternating current, resistance, and test diodes and transistors. To carry out a specific measurement, it is necessary to set the proposed measurement limit of the measured quantity (current, voltage, resistance) with a switch, taking into account the type of current (direct or alternating). The measurement result is presented on a digital readout device in the form of ordinary easy-to-read decimal numbers. The most common types of digital multimeter reading devices are liquid crystal, gas-discharge and LED indicators. On the front panel of such a device there is a function and range switch. This switch is used both to select functions and the desired measurement limit, and to turn off the device. To extend the life of the device's power supply, the switch should be in the “OFF” position when the device is not in use.
The main technical characteristics of digital devices that must be taken into account when choosing include:
- measurement range (usually the device has several subranges)
- resolution, which is often understood as the value of the measured quantity per unit of discreteness, that is, one quantum;
- input resistance, characterizing the device’s own energy consumption from the source of measurement information;
- measurement error, often defined as +,- (% of the read data + number of digit units).
The multimeter is often powered by a 9V battery, so before using the device it is necessary to check the battery power by turning on the device. If the battery is low, a symbolic battery image appears on the display. The multimeters used in the Electrical Engineering stand are powered by a rectifier built into the module.
1.3 Prepare a multimeter to measure DC voltage.
Table 2 - DC voltage measurements.
Classes +5 V +12 V -12 V AN BN CN A-B B-C C-A
Nominal +4.5 +12.4 -12.1 218 219 220 376 377 377
Measured +5 +12 -12 220 220 220 380 380 380
Abs. burial 0.1 0.4 0.1 1 1 0 4 3 3
Rel. burial (%) 2 1 0.8 0.9 0.4 0 1.1 1.1 0.8

1.4 Prepare a multimeter for measuring alternating voltage. Measure the resistance values ​​of the resistors indicated by the teacher. Enter the results in Table 3.
Table 3 - Resistance measurement.
Resistor R1 R2 R3 R4
Nominal resistance value, (Ohm) 10 20 30 40
Measured, (Ohm) 12 21 30 38
Absolute error 2 1 0 2
Relative error, (%) 0.001 4.7 0 5.2
Conclusion: we studied electrical measuring instruments used in laboratory work performed at the stand. Gained an understanding of the measurement limit, absolute and relative errors and other characteristics of pointer electrical measuring instruments, and acquired skills in working with digital measuring instruments.
Control questions.
1. The operating principle of a magnetoelectric system device is based on the phenomenon of interaction between the magnetic field created in this device by a permanent magnet and a current-carrying coil. As a result of the interaction, the angle of alpha rotation of the arrow (the coil rigidly connected to the arrow) is proportional to the magnitude of the current (J).
The device of the electromagnetic system consists of a coil with current and a ferrimagnetic disk, rigidly connected to the pointer, which can enter the internal cavity of the coil. This creates a magnetic field in the coil, the energy of which is proportional to the square of the current (J). The alpha rotation angle of the disk in devices is proportional to the square of the effective current value (J)
2. The limit of measurement is the determination of a physical quantity experimentally using measuring instruments.
3. The measuring limit of the device is divided by the number of lines on the scale.
4. The absolute measurement error is equal to the difference between the measurement result and the true value of the measured value.
A=Ah – A
The relative measurement error is the ratio of the absolute measurement error to the true value of the measured value expressed in %.
bA = A/A*100%
5. Measuring instruments are divided into 8 accuracy classes: 0.05; 0.1; 0.5; 1.0; 1.5; 2.5; 4.0. The figure defining the accuracy class indicates the most permissible value of the given basic error for a given device (in%)
6. Error when measuring any value with this device. The smaller, the closer the values ​​of this value are to the upper limit of measurement of the device; therefore, for better use of the accuracy of the device, they should measure the values ​​of the k/e value corresponding to the second half of the scale of the device.
A= A-Ah
7. Digital electrical measuring instruments have high accuracy (error from 0.1 to 1%), faster response, wide measurement ranges, and are easily equipped with digital computers that transmit results without distortion over unlimited distances.

State budgetary educational institution

primary vocational education professional lyceum No. 24, Sibay, Republic of Bashkortostan

Methodological development of the lesson

in the discipline "Electrical Engineering"

topic: “Electrical measuring instruments”

Developed by: higher education teacher

professional educational disciplines

I.I. Peredelskaya

Topic: “Electrical measuring instruments” corresponds to the main professional program according to the Federal State Educational Standard for NPOs in the academic discipline OP 01. “Electrical engineering” in the specialty “140.446.03 Electrician for repair and maintenance of electrical equipment (in the mining industry)

The methodological development is developed using modular training technology, which uses a variety of educational activities:

1. educational theoretical material has been developed according to the standard of the module and element, a list of recommended literature;

2. an entrance test is presented, on the basis of which the material studied at school, at the lyceum, in the previous module is repeated;

3. a logical scheme for studying new material using the Steinberg method is presented, where students must independently fill in the name of electrical measuring instruments using a textbook on the subject: “Electrical Engineering”;

4. assignment of an intermediate test, which is carried out after studying a new topic and allows you to evaluate the teacher’s knowledge.

This methodological development presents the plan for the current lesson UE 4 “Electrical Measuring Instruments” according to MB 2 “Electrical Devices” and educational materials.

Title UE 4 “Electrical measuring instruments”

Lesson topic: “Electrical measuring instruments.”

Lesson type: modular lesson

Lesson objectives:

No. Educational goals:

1) have an idea of ​​the purpose and classification of electrical measuring instruments.

2) know the symbols of electrical measuring instruments.

Developmental goal: to develop logical thinking in students.

Educational goal: to cultivate in students a sense of responsibility, the ability to cooperate in pairs and in groups

Educational and methodological support and TSO: handouts with UE 4, visual aids (battery, wires, lamp, switch, ammeter, voltmeter); interactive whiteboard, computer, tests (Appendix No. 1)

poster: “Power measurement in an alternating current circuit”, chalk illustrations.

Information sources:

1) textbook Yu.G. Sindyaev “Electrical engineering with fundamentals of electronics” 2002

2) textbook by A. Ya. Shikhin “Electrical Engineering” 1991

During the classes

MB 2 ELECTRICAL DEVICES

After studying MB 2, the student should:

have an idea:

On the purpose of electrical devices;

On the classification of electrical devices;

Designation, measurement error of electrical measuring instruments;

Methods for measuring electrical and non-electrical quantities;

Design, principle of operation, characteristics, diagrams of electrical devices.

Solve typical problems on electrical devices;

UE 4 ELECTRICAL INSTRUMENTS

1) have an idea:

On the purpose and classification of electrical measuring instruments;

About the types of errors of electrical measuring instruments.

Symbols of electrical measuring instruments;

Definition, designation of the absolute and relative error of the device.

Solve typical problems to determine the absolute and relative error of a device.

Appendix No. 1

ENTRANCE TEST

1. Write the name of electrical measuring instruments.

2. Is it true that the statement that electric machines include: a generator and an electric motor.

3. Select what applies to electrical switching devices.

Electrical switching devices are 1) a switch, 2) a button, 3) a switch, 4) a magnetic starter, 5) a bell, 6) a batch switch.

Lesson No. 25 “Electrical measuring instruments.”

Electrical measuring instruments are used to measure electrical quantities ( voltage, resistance, current, power, frequency) and non-electric quantities ( temperature, pressure, time, liquid level in the container, etc.).

Electrical measuring instruments are classified:

1. by the type of quantity being measured.

2. according to the principle of action.

3. by type of current.

4. depending on the position of the device in space.

Symbols of electrical measuring instruments are presented in table No. 5 (See “Tutorial on electrical engineering” on the topic: “Electrical measuring instruments”)

TASK No. 1

1. Read the lesson material on the topic: “Electrical measuring instruments.”

2. Complete the lesson notes in the following order:

2.1 Draw a logical diagram No. 1 “Electrical instruments” in this case:

1) in paragraph No. 1: “Purpose of electrical measuring instruments,” indicate the name of electrical and non-electrical quantities;

2) in paragraph No. 2,3,4,5, indicate the name of the symbols of electrical measuring instruments, using table No. 5

3. Homework: prepare for a test on the topic: “Electrical measuring instruments”:

1. Symbol of e/i item according to the type of quantity being measured.

2. Conventional designation of e/i item according to the principle of operation.

3. Symbol of electric power supply by type of current.

4. Symbol of e/i item depending on position in space.

Logical diagram: “Electrical instruments”

APPENDIX No. 1

TEST TASKS

Option 1

1. What material are the wires made of?

a) made of aluminum and brass;

b) made of copper and brass;

c) made of aluminum and copper;

2. What is the designation for resistor?

3. Find the current ifR= 4 Ohm,U= 12 V
b) 3 A

a) sequential;

b) parallel

c) mixed

5. What symbol is used for a voltmeter?

6. What is power used for in active resistance?

a) heat dissipated in space;

b) only for useful work

c) for useful work or for heat dissipated in space;

7. In what units is the inductive reactance of a coil measured in the SI system?
b) D
8. Choose what current value is lethal for a person?

c) over 0.1 A

9.What does ώ mean?

a) angular conductivity of alternating current;

b) angular frequency of alternating current

c) AC resistivity

10. What elements does the block diagram of an electric drive consist of?

a) converter, electric motor, gearbox, working mechanism;

b) variator, electric motor, gearbox, working mechanism

c) relay, electric motor, gearbox, operating mechanism

Option 2

1. What material is the switch body made of?

a) made of aluminum;

b) made of copper;

c) made of plastic;

2. What is the designation for a nonlinear resistor?

3. Find the current ifR= 4 Ohm,U= 12 V
b) 3 A
4. Indicate the type of connection of the conductors made in the diagram?

R3

a) sequential;

b) parallel

c) mixed

5. What symbol is used for an ammeter?

6. Which symbol represents the delta-connected stator winding?
b) ∩
7. How is magnetic permeability indicated?
b) N
8. Specify the formula for absolute error

a) ∆Á = Á1 – Á2

b) ∆Á = Ái- Ád

c) ∆Á = Ád - Ái

9. Select the electrical network protective device

a) fuse

b) button

c) switch

10. When does the generator set charge the battery?

a) when the engine is idling

b) when the electric motor is not running

c) with the electric motor running

Key to test option 1

1. P.A. Butyrin Electrical engineering: a textbook for beginners. prof. education / P.A. Butyrin, O.V. Tolcheev, F.N. Shakirzyanov; edited by P.A. Butyrina. – 6th ed., erased. - M.: Publishing center "Academy" 2008 - 272 p.

2. Problem book on electrical engineering: a textbook for beginners. prof. education: textbook for medium. prof. education / [P.N. Novikov, V.Ya. Kaufman, O.V. Tolcheev, etc.] – 2nd ed., erased. - M.: Publishing center "Academy" 2006 - 336 p.

3. Proshin V.M. Laboratory and practical work in electrical engineering: a textbook for beginners. prof. education / V.M. Proshin - 2nd ed., erased. - M.: Publishing center “Academy” 2007 – 192 p.

Additional sources:

1. Yarochkina G.V. Electrical engineering: workbook: textbook for beginners. prof. education / G.V. Yarochkina, A.A. Volodarskaya – 5th ed., erased. - M Publishing Center "Academy" 2007 -96 p.

2. Electrical engineering: Textbook. for vocational schools / A.Ya. Shikhin, N.M. Belousova, Yu.Kh. Polyakov, etc.; Ed. AND I. Shikhina. – M.: Higher. school, 1991. - 336 pp.: ill.

3. Kreidlin L.N. Joinery, carpentry, glass, parquet work: a textbook for beginners. prof. education - M.: Prof.Obr.Izdat, 2001. - 352 p.

INTERNET-RESOURCES.

Http://www.college.ru/enportal/physics/content/chapter4/section/paragraph8/the

ory.html (The site contains information on the topic “DC Electric Circuits”)

- http://elib.ispu.ru/library/electro1/index.htm(The site contains an electronic textbook for the course “General Electrical Engineering”)

- http://ftemk.mpei.ac.ru/elpro/(The site contains an electronic guide to the direction " Electrical engineering, electromechanics and electrical technology").

- http://www.toe.stf.mrsu.ru/demoversia/book/index.htm(The site contains an electronic textbook for the course “Electronics and Circuit Engineering”).

• 
  http://www.eltray. com. (Multimedia course “Into the world of electricity like for the first time”).
• 
  http://www.edu.ru.
• 
  http://www.experiment.edu.ru.

The lesson is designed using group forms of work, which ensures the development of teamwork skills, instilling a sense of responsibility, stimulating mental operations: logical thinking, the ability to draw conclusions, analyze, the ability to write abstracts, as well as the ability to objectively evaluate the contribution of everyone in the group, developing public speaking skills speeches.

Download:

Preview:

Methodological development of the lesson

Discipline: electrical and Electronics

Subject: “Electrical measuring instruments (test on the topic)”

Developed by: Ponomareva O.A. - teacher at the Nizhny Novgorod Industrial and Technological College, Nizhny Novgorod

EXPLANATORY NOTE

The lesson is designed using group forms of work, which ensures the development of teamwork skills, instilling a sense of responsibility, stimulating mental operations: logical thinking, the ability to draw conclusions, analyze, the ability to write abstracts, as well as the ability to objectively evaluate the contribution of everyone in the group, developing public speaking skills speeches.

Technological lesson map

Subject: Electrical measuring instruments Test on the topic)

Lesson type: test lesson

Lesson objectives:

Repeat and generalize knowledge on the topic “Methods for measuring parameters of electrical circuits. Designs and principles of operation of electrical measuring instruments;

To promote the development of the ability to apply acquired knowledge in physics, electrical engineering, understanding the inevitability of errors in any measurement;

To promote the development of interest in learning, discipline, and the ability to work in a team.

Equipment

Electrical measuring instruments

Training tables, sample devices

Diagnostics

Students know:

That the measurement of any quantity consists in comparing it with a quantity of the same nature, taken as a unit;

That in many cases it is not the quantity that is needed that is measured, but some other one, and the one sought is then found using the appropriate formula;

Designs of electrical measuring instruments of various systems;

Methods for measuring electrical parameters Chains.

Lesson structure

Organizational moment 1 min

2. Updating knowledge (diagnostics of knowledge and skills) 5 min

3. Independent work in groups 13 min

4. Presentation of the results of the groups’ work. 23min

5. Lesson summary. 3 min

Literature:

1. M.V. Galperin. Electrical engineering and electronics. 2010
2. I.A.Danilov, P.M.Ivanov. General electrical engineering with the fundamentals of electronics. M.2013.
3. M.V. Nemtsov, M. L. Nemtsova. Electrical engineering and electronics. M. Academy. 2015
4. p/r B.I. Petlenko. Electrical engineering and electronics. M. 2005.
5. V.S. Popov, S.A. Nikolaev. General electrical engineering with fundamentals of electronics. M. 2005
6. Yu.G.Sindeev.Electrical engineering with the basics of electronics.Rostov-on-Don.Phoenix.2014
7. V.M.Proshin.Electrical engineering for non-electrical professions.M.Academy.2014
8. V.I. Poleshchuk. Problem book on electrical engineering and electronics. M. Academy. 2010
9. - http://elib.ispu.ru/library/electro1/index.htm
10. - http://ftemk.mpei.ac.ru/elpro/

Technological lesson map

APPLICATIONS.

1.Tasks for independent work.

Group 1.

1. Give definitions of measurement errors.

2. Choose a voltmeter that has greater accuracy in measuring voltage 30V:

1st voltmeter with an upper measurement limit of 50V and an accuracy class of 2.5;

2nd voltmeter with an upper limit of 100V and accuracy class 1.5.

Group 2.

1. Talk about EIP of electromagnetic and magnetoelectric systems.

2. It is required to measure the electrical Current in a DC circuit. Which device of which system is needed? Use the table to show the connection diagram.

It is required to measure the voltage in the AC circuit. What device is needed?

Group 3.

1. Talk about the devices of the electrodynamic system.
2. It is required to measure the electrical power in the circuit:

A) direct current

B) single-phase alternating current

B) three-phase alternating current

What devices can do this? Indicate the connection diagrams for each case in the table.

Group 4.

1. Talk about induction system devices.

2.Explain the structure of the device (using a sample).

Group 5.

1. Find from the table and explain the circuit diagrams for connecting devices for measuring voltage, el. current, el. voltage, resistance, el. power.

Group 6.

1.Tell about schemes that allow you to expand the limits of measurements:

a) electric current

B) electrical voltage

2. TEST

Electrical Instrumentation Systems

Questions:

I. Electrical measuring instruments are intended for…

II. To measure electrical current use...

III. To measure electrical voltages are used...

IV. Electric power current is measured...

V. Electrical consumption accounting energies are led with the help of...

VI. For measurements in DC circuits, use...

VII. For measurements in alternating current circuits...

VIII..For electrical measurements. power in DC and AC circuits is used...

IXInduction devices operate on the principle of a rotating magnetic field and therefore can only operate...

Answers:

1-electromagnetic devices

2-counters

3-in AC circuits

4-ammeters

5-electrodynamic devices

6-voltmeters

7-watt meters

8-control over the operating mode of units, power lines, as well as accounting for quantity

Generated electricity energy

9-magnetoelectric devices

KEY

I II III IV V VI VII VIII IX

8 4 6 7 2 9 1 5 3