Electrical voltage and electrical voltmeter. Subject. Electrical voltage. Voltmeter. Development of new knowledge and methods of action
Respect! The administration of the site is not responsible for the replacement of methodical developments, as well as for the consistency of the development of the Federal State Educational Standard.
This lesson was filmed on video on September 21, 2016 on the basis of MBOU ZOSH No. 21 in Nizhnyokamsk Nizhnyokamsk district of the Republic of Tatarstan as part of the municipal professional mastery competition “Teacher of Rock - 2016”.
At the time of hiring, the class had 20 students in the 8th grade of MBOU ZOSH No. 21, 16 members of the jury - methods of managing the education of Nizhny Kamsk, as well as readers and competitors, a significant group of operators.
The students with whom the work was carried out were not known to me, but during the daily lesson I was informed and looked at the possibilities of different situations in the world.
This video contains the material where I share the authoritative evidence of the research and testing of my methodical ones “The use of information and communication technologies in pedagogical activities.” Today's children, who are traditionally addicted to gadgets, want to be nurtured in a great way. Especially since the physics classroom has not been updated since the opening of school. There is no interactive whiteboard in the classroom, without wondering at all, with the help of a laptop and a projector I continue this “transition” and find a solution to make the lesson more accessible and effective.
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Lesson objectives: |
Subject: Formulate the concept of "stress". Enter one unit of voltage. Familiarize students with the rules for measuring a voltmeter. Learn practical skills about folding an electric lance, reading and drawing diagrams, and checking voltage. |
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Lesson instructions: |
a) forming a statement about voltage, organizing the acquisition of basic understanding of this, forming a scientific view of scientists (Subject result). b) development of generating ideas, identifying cause-and-inheritance connections, working in groups, accessing alternative sources of information, forming and analyzing facts while observing and explaining the facts, while working with the text of the friend (Meta-subject result). c) formation of the ability to engage in one’s initial activity, formation of interest in physics in the analysis of physical phenomena, formation of motivation by setting cognitive tasks, revelation of the connection between theory and evidence, development of respect, thoughts, logical and creative thoughts (Special result). |
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Methods of learning: |
reproductive, problematic, heuristic. |
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Forms of organization of educational activities of students: |
collective, individual, group. |
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Get started: |
handbook, laboratory equipment, reflection cards, different teaching materials, laptop, projector, internet. |
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Lesson type |
Development of new material |
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Electric strum robot. Voltage, one voltage – 1 Volt. Voltmeter. Voltage reduction. |
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Installation of the bathroom |
Voltmeter, dzherel struma, light bulb, coupling darts, key, dispensing material. Exhibition of small children on the theme “Electrics” Physical newspaper – additional columns “What is the value of skins”, “Historical news”, “Facts”... |
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Demonstrations |
Voltage reduction on different plots of Lanzug |
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Lesson plan |
Lesson progress |
Spare position |
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1) Organizational part: |
Good day, guys! My name is Akhmetova Aizarya Zanifivna. I wish everyone a good mood and far away work. Sit down. |
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1 slide |
Lesson motto:“I smell - I forget, I understand - I remember, I hesitate - I understand” (Chinese proverbs) |
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2) Verification of knowledge: 2 slide |
Look respectfully at the screen. What are we looking for in the picture? (Field). In life, this field is very important, but according to electricians, the field is empty? (so, more electric) |
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3-4 slide; 3rd animation “El.Tok” |
Now, what should we watch out for? (Pull the water through the pipe). And in an electric train, what can leak? (El. Strum) |
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Virsh (Work in pairs, given to 3 students) 1 navch. works for my daughters, 2 – work in pairs. (one hour) |
“How is the strength of the strum calculated?”– versh I don’t praise myself for nothing, |
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Confirmation. 8 A 5 slide At the same time I play “I believe it or not” in front of the class. |
Why is the strength of the stream in lancusion different, since the charge is equal to 2.4 kC? Guys, you have green and red colored signal cards on your desk. I will read out the propositions, and for 3 seconds you will guiltyly raise the red card, as it is not suitable for the affirmations, and the green card, as it is suitable.
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Re-verification. Self-esteem. Checking the homework. 6 slide Self-esteem. |
Let’s check it out now. I hope everything is powered correctly. Give yourself 3 points, if you have shown mercy 1-2 times - give 2 points, if 3 or more - give 1 point. Sign it in the margins of the Zoshits or on your own pieces of paper. |
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Demonstration of Rukh Vantage with a dynamometer 7 slide |
In the 7th grade, you are familiar with the term “mechanical robot.”
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Animation, rozvagi 2 |
- Is it possible to solve a similar situation with electricity? Tobto. Just as in mechanics there is a mechanical robot, then in electricity...? (There is a robot struma) – I work here…. (EP) What conclusion can we take from what we have said? |
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Viznachennya |
The work of the forces of the electric field that creates the electric current is called robotically struma. In the process of such robots, the energy of the electric field is transformed into another type of energy - YAC? (mechanical, internal, etc.) KIND OF WHAT TO LAY WITH THE ROBOT STRUM? (like the strength of a stream, an electric charge that flows through the lancet in 1 s) - with whom you switched in the previous lessons and in the viconn of L / R. |
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Follow-up Having divided into 2 groups, the students freeze and collect lantsugs. Make a difference ammeter display in Fig. 63 and 64 Animation, rozvagi 3 (Lamp demonstration) |
And now, boys, each of you has leaves on your desk with the words “Investigation.” The word is written on the collar. (On the pieces of paper it is written Dielectrics: distilled water, glass, plastics, benzene, oils, mica, porcelain, wind, gum, carved resin, wood; Guides: breakdown of salts, breakdown of acids, wood, copper, aluminum, gold, water, graphite, copper,) On 2 desks there are inscriptions DIELECTRIC and CONDUCTOR. The slide shows a group of dielectrics and conductors. Make sure you have your say in the group and go to the table where there is a card with the name. Children share, etc. into 2 groups and conduct follow-up: the collections of the lancug blink. Children, marvel at the ammeter reading. Sound out the skin group. (Called skin group). Since the ammeter shows less power in the lamp with a brightening lamp, and a larger flow passes through the lamp with a lamp, then why is the brightness of the lamps different? (Types of boys) Idealizations, an extreme fall, if the ammeter readings are the same. Well, the robot should lay down the struma as a result of the strength of the struma, and th from other quantities…. (Yaku is called electrical voltage or just under stress) |
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3) Development of new material: |
So, today we are learning that such tension, which begins to fade away, is known from its basic characteristics. |
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Write down the number and topic of Zoshiti's lesson (On doshtsі) |
Topic of our lesson: "Electrical voltage. Single voltage" |
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Doshtsi plan 1 one per desk |
When we become familiar with the new value of the value, we are already familiar with it plan. Children, find out the meaning of your friend, who knows - read to the class. (p. 91) |
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Viznachennya |
Electrical voltage - This is a physical quantity that characterizes the electric field |
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Viznachennya |
Visnovok: The voltage shows how the robot is working. field when a single positive charge moves from one point to another. |
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Appointment I’ll prescribe it in English, immediately with a slide |
- Voltage is indicated U; - robot A; - letter charge q; |
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Coming from the voltage: knowing the robot, the struma on the data of the Lanczyga ate the whole thing. the charge that has passed through the whole plot, we can remove the level, so that the robot stream when moving a single piece of food. charge: |
Card from the treasures. |
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Calculation formula Animation, rozvagi 4 |
U = A/ q →A= Uq; q = A/U |
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(Mine notice) Behind the date of one child |
- Do you know this portrait? (So, Alessandro Volta) What do you think a unit of electrical voltage is called? (Volt) . Voltage settings U. Let's go back to the voltage formula and try to get one of the values. U = A/ q; 1 V = 1 J/C |
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Only one in the world |
They take it as one voltage, so I ate it. the voltage at the ends of the conductor, when moving an electrical charge of 1 C behind this conductor is 1 J: 1 V = 1 J/C In the next lesson you will learn about a device for measuring voltage - a voltmeter. Connect the voltage at the lancet in parallel, try to pick up the lancet from the voltmeter. |
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Slide 12 Attachment for vimiryuvannya Designations on the diagram Connection rules |
- How can you understand the voltage sense? An electric current similar to the flow of water at rivers and waterfalls, then. similar to the flow of water from the high to the lower. Charge q represents the mass of water, and the voltage – the difference between the rivers and the pressure of the water in the river. |
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Slide 13 |
The work that interacts with water, that falls, lies in its mass and height of the fall, and also lies in potential energy. The greater the difference in the flow of water, the greater the effect of the water. The work forces the stream to lie under the electric charge and voltage on its conductor. The greater the voltage of the lance, the greater the robotic flow for the same amount of charge. In the 10th grade, the electric field is expressed through the difference in potential energy. Just as there is no voltage in the lancus, there is no electric current in it (as there is no flow in the lake or the difference between the rivers and the relief). |
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4) Home improvement: recorded at home in advance |
§39-40, take a test on the phone on the topic “Electrical voltage”. |
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Creative project. Slide 14 |
Klass is working on a creative project. Would you like to try to paint your own picture? This will need to be explained to the electrician. |
If I don’t get it, then homework |
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Reflection(green and red circles are attached to the baby light bulbs using magnets). (1 xv) A piece of paper is attached to the bottom, on which a light bulb is daubed. Before entering. |
PLAN(on doshtsі)
- Viznachennya
- Appointment
- Only one in the world
- Calculation formula
- What a way to pretend
- Designations on the diagram
- Rules for connecting to Lanzug
Min - information
VOLTA Alessandro - Italian explorer of nature, physicist, chemist and physiologist. His most important contribution to science was the venohid dzherel of the stationary struma, which played an initial role in further investigations of electrical and magnetic phenomena.
Individual card for strong students
- Do you know the voltage on the Lanczyg's line, because when passing through a new charge of 15 C, the stream generates 6 kJ for the robot?
- When 60 C of electricity are transferred from one point of the electrical lancet to the robot in 12 minutes, 900 J are added to the robot. Calculate the voltage and force of the stream in the lancet.
Lesson topic: Electrical voltage. Voltmeter
Lesson type: learning and initial consolidation of new knowledge and methods of action
Electrical voltage. Voltmeter
Lesson objectives: Organize the activity, understanding and first memorizing new knowledge and methods of activity on the topic: “Electrical voltage. Voltmeter".
Lesson instructions:
Ensure that students are aware of the concepts of stress and units of the world;
Create a mind for the development of motives for achievement, positive development of knowledge, discipline;
Ensure the formation of the mind, the ability to see the head, put together a plan, take notes, take notes, develop the mind of private - search activity, formulate hypotheses and the highest.
Lesson heading:
1. Organizational stage
Greetings, checking in on daily activities, checking the students’ preparedness before the initial lesson, identifying the objectives of the lesson and the delivery plan.
2. Checking your homework
Testing 2 options for 6 days
Test on the topic: “Strum power. One force struma. Ammeter. Vimiryuvannya sil struma"
1. The strength of the strum is a physical quantity that is ancient...
a) ...an electric charge that passes with an electric lance in an hour of work.
b) ...an electric charge that passes through the transverse section of the conductor.
c) ...an electric charge that passes through the transverse section of the conductor in 1 s.
d) ...an electric charge moved in 1 sec from the positive pole of the jerela struma to the negative one.
2. What is the name of one sili struma?
a) Joule (J). b) Watt (W). c) Coulomb (Cl). d) Ampere (A).
3. Convert the power supply to 0.05 A and 500 µA.
a) 50 mA and 0.5 mA. b) 500 mA and 5 mA.
c) 500 mA and 0.5 mA. d) 50 mA and 5 mA.
4. What is the strength of the stream in the lancius, because with a stretch of 4 strokes across the transverse beam the charge is 120 C?
a) 30 A. b) 0.5 A. c) 5 A. d) 3 A.
5. The power of the strum is vibrating...
a) ...galvanometer. b) ...a galvanic element.
c) ... with an ammeter. d) ...electrometer.
6. According to the readings of ammeter No. 2, the strength of the stream in the lance is still 0.5 mA. How can the force of the stream be recorded by ammeters No. 1 and No. 3?
a) No. 1 - less than 0.5 mA, No. 3 - more than 0.5 mA.
b) No. 1 – more than 0.5 mA, No. 3 – less than 0.5 mA.
c) No. 1 and No. 3, as well as No. 2, – 0.5 mA.
1. What formula is used to indicate the strength of the struma?
a) N = A/t. b) I = q/t. c) m = Q/? d) m = Q/L.
2. Express the power of the stream, which is more than 0.3 A and 0.03 kA, in milliamps?
a) 30 mA and 3000 mA. b) 300 mA and 30,000 mA.
c) 300 mA and 3000 mA. d) 30 mA and 30,000 mA.
3. Why are the equalities in amperes between 800 μA and 0.2 kA?
a) 0.008 A and 200 A. b) 0.0008 A and 20 A.
c) 0.0008 A and 200 A. d) 0.008 A and 20 A.
4. For a conductor connected to the lancet at 2 points, the power of the stream reached 700 mA. How much electricity passed through this crossbar in one hour?
a) 8.4 Kl. b) 14 Kl. c) 1.4 Kl. d) 84 Kl.
5. The strength of the current in which lamp is shown by the ammeter turning on to what extent?
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d) In the skin of them.
6. At what point of the lamp and in which switch do you need to turn on the ammeter to determine the strength of the current in the switch?
a) Until the ding (at the direct electric current).
b) After the jingle.
c) The bile of the positive pole dzherela struma.
d) Whatever the business of this Lanzug.
Types
3. Updating the subjective information of students
1. The strength of the struma can be judged by the readings of the ammeter, or by the action of the struma (the more tension the thread is, the greater the force of the struma)
Food: Where does the power of the strum lie?
Demonstration: an increase in the ammeter reading corresponds to an increase in the number of cores.
Subject: The strength of the strumu lies in the form of any size connected with the string strumu.
2. The dzherelo struma is created by an electric field, which is created by a robot from a distribution of electric charges.
4. Development of new knowledge and methods of action
The robot of the electric field that the struma creates is called the robot struma.
A-robot struma
The stronger the electric field, the greater the fluidity of the flow of charged particles, the greater the transfer of charge, and the greater the electric flow.
The electric field is characterized by its magnitude, which is called the voltage of the electric field.
Electric field voltage is a physical quantity that characterizes the effect of the electric field on a charged particle.
U is the voltage of the electric field.
U = A/q - the voltage shows to each robot the current electric field of displacement of a unit of charge to this part of the lancet.
Safe voltage 42 St.
A voltmeter is a tool for measuring voltage.
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The voltmeter is connected to the low points of the lanyard, between which the voltage is required (in parallel), and plus is plus, and minus is minus.
5. The first step is to check the understanding of the drug
Feeding:
1. Why call a struma a robot? (To the work of the electric field that creates the strum)
2. What is called electric voltage? (Physical quantity that characterizes the effect of the electric field on the charging part)
3. Assigned voltage units. (U, volty)
3. What is the name of the voltage suppression device? (Voltmeter)
4. How do you turn on a voltmeter in a Lanzug? (Connect to small points of the lancug, between which you need to reduce the voltage (in parallel), and plus to plus, and minus to minus)
6. Stage of securing the wound
Work from the collection of the book of physics (V.I. Lukashik, E.V. Ivanova) No. 1265, 1266-usno.
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7. Stage of formalization and systematization
Unleash the command:
1. Determine the voltage at the lancun's edge, as when a charge of 15 C is passed through the robot's viconan boule of 6 kJ.
U = A/q = 6000 J/15 C = 400 St.
2. When transferring 60 C of electricity from one point of the electric lancet to another, 900 J are transferred to the robot in 12 minutes. Calculate the voltage and force of the stream in the lancet.
U = A/q = 900 J/60 C = 15 V
I = q/t = 60 C/720 s = 0.08 A.
8. Pouches, home improvement p.39-41
9. Reflection
Reflection. (Draw the arrows until you reach the points that indicate your final lesson).
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List of wikilist literature
1. Perishkin A.V. physics 8th grade - M: Bustard, 2009.
2. Lukashik V.I., Ivanova O.V. Collection of physics classes 7-9 grades - M.: Prosvitnitstvo, 2008.
3. Chebotarova V.A. Physics tests. 8th grade – Vydavnitstvo “Ispit”, 2009.
Have you ever tried to inflate your balloons at any time? One inflates the windshield, and the other inflates much less in the same hour. Without a doubt, the first one does more work than the other.
With the voltage sockets, it’s the same way. To ensure the flow of particles from the conductor, you need to create a robot. And this is the job of the job. The work of the dzherel is characterized by voltage. The larger it is, the more work the body does, the brighter the light bulb in the lamp burns (for other minds).
The current voltage is used to create an electric field to move the charge
up to the amount of charge that moves to the edge of the lancet.
U = A q where \(U\) is the voltage, \(A\) is the electric field, \(q\) is the charge.
Show your respect!
One unit of voltage in a CI system is [\(U\)] = \(1\) B (volts).
\(1\) volt is higher than the electrical voltage at the lancet end, and when a charge is passed through, which is higher than \(1\) C, the robot operates, equal to \(1\) J: \(1\) V \(= 1\) J / 1 Cl.
Everyone wrote “(220)” on their household appliances. Vaughn means that there is a robot (220) J on the displaced charge (1) Cl.
The difference between volts and volts is equal to multiples of one unit - millivolts and kilovolts.
\(1\) mV \(= 0.001\) V, \(1\) kV \(= 1000\) V or \(1\) V \(= 1000\) mV, \(1\) V \( = 0.001 kV.
To measure the voltage, use a device called a voltmeter.
All voltmeters are designated by the Latin letter (V), which is marked on the dial of the devices and shown in the schematic diagram of the device.
In school minds, voltmeters are used, depicted on a small scale:
The main elements of a voltmeter are the body, scale, pointer and terminals. In the labels, label the signatures with a plus and a minus, and for clarity you can see different colors: red – plus, black (blue) – minus. Use this method to correctly connect the terminals of the device to the power wires connected to the device.
Show your respect!
In place of the ammeter, which is connected in series to the lancet, the voltmeter is connected to the lancet in parallel.
When you turn on the voltmeter at the constant voltage level, it is necessary to adjust the polarity.
It is better to start the construction of an electric lancet with all the elements, including a voltmeter, and then connect it at the very end.
Voltmeters are divided into adjust the stationary strumі zminnogo struma.
Since the device is used for changing the lanyard, it is customary to display a wiggled line on the dial. If the device is used for the lancets of a stationary stream, then the line will be straight.
Stationary voltmeter | Voltmeter |
You can sever the respect on the klemmi priladu. If the polarity is indicated (“(+) and “(-)”), then this is a device for adjusting the constant voltage.
In some cases, vicoristic letters (AC/DC). In the English translation (AC) (alternating current) is an alternating current, and (DC) (direct current) is a constant current.
A voltmeter is inserted at the lance of the exchanger to adjust the exchanger. It has no polarity.
Show your respect!
To check the voltage, you can use a multimeter.
Remember that high voltage is not safe.
What will happen to people if they appear in a row behind a sunken exposed cable that is under high voltage?
The fragments of earth act as a conductor of electrical current, like a bare cable that, having fallen in, is under voltage and may break down, which is not safe for people.
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Physics lesson for 8th grade "Electrical voltage. Voltage units. Voltmeter"
She gave a lesson to the lesson: Tolstikh Yulia Volodymyrivna, teacher of physics and computer science, I qualification category, Municipal Educational Institution of Educational Sciences of the village of Kuzminskie Otverzhki, Lipetsk district, email: [email protected]
Lesson meta:
- Data for understanding the voltage and explanation; learn the formula for unit voltage; Learn the device for adjusting the voltage and the rules for including it in the Lanzug.
- Develop skills in folding Lanczyg; miscellaneous; memory; language; interest in the subject; It's practical to get rid of knowledge.
- Recruitment has a sense of reliability, collectivism, consistent commitment to the final task, and self-discipline.
During the lesson with teacher O.V. Perishkina.
1. Checking your homework.
The teacher reads the meal:
- The strength of the strum is indicated.
- The power of the strum is vibrating.
- Formula for calculating sili struma….
- Approaches the lantsyug…..
- One unit of electric charge….
- How many amperes are in 1 mA?
Types: select an option
- A-I-R
- Voltmeter-hour-amperemeter
- F = m a-I = q/t-q = I t
- parallel-sequential-first
- 1 sec-1 meter-1 Coulomb
- 0.001A-10A-100A
Cards from tasks lure weak students, and others work for children and nutrition
2. Explanation of the new material.
1. Safety equipment for working with electrical installations.
- Guess, guys, what is called a robot struma? The robot of the electric field that the struma creates is called the robot struma.
- What is the size of the robot struma? What to lay there for?
We can happily say that there is a force in the current, which is the electric charge that flows through the Lancug at 1 s, as well as a new quantity for you, which is called electric voltage.
Voltage is a physical quantity that characterizes the electric field and shows how the electric field operates when a single positive charge moves from one point to another. It is designated by the letter U. To calculate the voltage, the following formula is used: U = A / q. The unit of voltage is named Volt (V) in honor of the Italian scientist Alessandro Volta, who created the first galvanic element. , which robot has a displacement of an electric charge of 1 C from whose conductor is equal to 1 J. 1V = 1J / 1C Volts are equal to multiples of the same unit: millivolts (mV) and kilovolts (kV). 1mV = 0.001V 1kV = 1000V To adjust the voltage at the poles, use a struma or for any part of the Lancug, install an apparatus called a voltmeter. Press the voltmeter to reach the small points of the lantz, between which you need to control the voltage. I would call this inclusion parallel. Folding lance and armchair circuits to place a voltmeter. It is explained how the device is indicated on the diagram.
Voltage
Litera U
Formula U = A/q
Odinitsa 1 Volt
More than one 1kV = 1000V
Multiples of units 1mV = 0.001V
Prilad voltmeter
Inclusion in Lanzug in parallel
Demonstration of voltmeters of different types with explanation and explanation of their operating principle.
3. Consolidation of acquired knowledge.
Write down 2 options and select two students for independent work.
Convert voltage values in Volts:
1st option:
2nd option:
Workplace for robots with class:
Zavdannya 1: Draw a diagram of an electric lancet, which consists of a battery, an electric switch, a key, a voltmeter and an ammeter, which varies according to the voltage on the switch and the power of the switch in the other. On the diagram, mark the signs of pressure on the battery, ammeter and voltmeter, following the rules of their connection. Point the arrows straight at the struma in the lancets and straight at the flow of electrons at the new one.
Zavdannya 2: How does a robot experience an electric field when a charge of 4.5 C is moved through the transverse cut of the filament of a hot lamp, since the voltage on the lamp is 3 V?
(A = Uq = 3 B * 4.5 C = 13.5 J)
Zavdannya 3: When passing through the same amount of electricity, one conductor has a voltage of 100 J, and the other – 250 J. Which conductor has more voltage? How many times?
(When a large amount of electricity passes through the conductor, the voltage will be greater in that case if the robot flow is larger. In the other type of robot the flow is greater by 250 J/100 J = 2.5 times)
Zavdannya 4: What types of electrical voltage do people encounter in everyday life? (127V, 220V)
4. Supplementing bags for the lesson.
Nutrition and nutrition.
- Why call a struma a robot?
- How can I explain the electrical voltage at the Lanczyg distance?
- Formula for calculating voltage.
- The same and multiple units of voltage.
- The purpose of the voltmeter and the rules for including it in the Langsug.
Well done, boys! Lesson grade.
5. Home gardening. §39-41 Ex 16 ( A.V. Perishkin)
Under electrical voltage, we understand the robot that uses an electric field to move a charge with a voltage of 1 C (coulomb) from one point of the conductor to another.
How is the voltage to blame?
All words are composed of atoms that have a positively charged nucleus, around which other negative electrons circle with great speed. Sometimes the atoms are neutral, so the number of electrons is equal to the number of protons in the nucleus.
However, as soon as a number of electrons are selected from atoms, they will tend to attract the same number of electrons, forming a positive field around themselves. If electrons are added, then there is an excess of them and a negative field. Potentials are formed - positive and negative.
There is no mutual burden in their interactions.
The greater the magnitude of the voltage - the difference in potentials - the stronger electrons from the material with their excess will instead be drawn to the material with their deficiency. Tim the strongest will be the electric field and its voltage.
If we connect potentials with different charges of conductors, then the electric one will straighten the flow of the charge, so that the difference in potentials will not be eliminated. To move the electric field force along the conductor of charges, construct a robot that is characterized by the concept of electric voltage. 
What does one have to live with?
Temperature;
See the tension
Constant voltage
The voltage in the electrical circuit is constant, since there is always a positive potential on one side and a negative potential on the other. The electricity in this connection is direct and unchangeable.
The voltage in the lancus of the stationary stream is rectified by the difference in potentials from its ends.
When connecting the device to a permanent source, it is important not to mix up the contacts, otherwise the device may go wrong. The classic butt of the battery is constant voltage. Establish barriers when it is necessary to transmit the energy of large systems: they are used in all types of transport - from motorcycles to spacecraft, in military technology, electricity and telecommunications, in case of accidents not electrically safe, in industry (electrolysis, smelting in electric arc furnaces, etc.
Voltage change
If you periodically change the polarity of the potentials, or move them in space, then the electricity is directly at the gate. The number of such changes per hour shows a characteristic called frequency. For example, the standard 50 means that the polarity of the voltage circuit changes 50 times per second.
The voltage in the electrical circuits of the exchanger has a time function.
The law of sinusoidal vibrations is most often used.
So go beyond the shell of what blames the cat of asynchronous motors for the shell of the wrap around it to the electromagnet. When the wrapper is ignited within an hour, a sinusoid comes out.
It consists of four wires - three phase and one zero. the voltage between the neutral and phase wires is 220 and is called phase. There is also a voltage between phases, called linear and 380 V (potential difference between two phase wires). Depending on the type of connection in a three-phase circuit, you can separate the phase or line voltage.