Electrical voltage unit voltage voltmeter. Electrical voltage. Significance, you see, only a few die. Development of new knowledge and methods of action
A lesson on exploring the concept of electrical voltage, which is designated as one unit in the world. Another part of the lesson is important for demonstrating the devices for adjusting the voltage on the Lanzug section and their features.
If you point out a standard butt about the sense of the well-known writing of any household appliances “220 U”, it means that the Lanzug dealer has a 220 J power with a displaced charge of 1 C.
Formula for voltage reduction:
Work of the electric field due to the transferred charge, J;
Charge Cl.
So, one voltage can be measured like this:
Between the formulas for calculating the stress and force of the flow, there are interconnections, for which respect is given: i. In both formulas there is the magnitude of the electric charge, which can appear in color when the action is carried out.
To adjust the voltage, use a device called voltmeter(Fig. 2).
Small 2. Voltmeter ()
There are different voltmeters based on the peculiarities of their operation, but the principle of their operation is based on electromagnetic activity. All voltmeters are designated in Latin letters, as they are marked on the dial of the device and are shown in the schematic diagram of the device.
In school minds, they use, for example, voltmeters, images of baby 3. It will help to measure the voltage in electric lances during the hour of laboratory work.
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Small 3. Voltmetry
The main elements of a demonstration 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. This is done to ensure that the terminals of the device are correctly connected to the conductor wires connected to the power supply. In place of the ammeter, which is connected in series to the lancet, the voltmeter is connected to the lancet in parallel.
Insanely, if any electric vibrating device is subject to minimal leakage on the lance, which is observed, then the voltmeter has such design features that through it there is a minimal flow. This effect can be ensured by selecting special materials that will ensure minimal charge flow through the device.
Schematic representation of a voltmeter (Fig. 4):
Small 4.
The electrical circuit (Fig. 5) is imaginable for the butt, in which a voltmeter is connected.
Small 5.
The lancet has a minimal set of elements: a heater, a frying lamp, a key, an ammeter, connections in series, and a voltmeter, connections in parallel to the light bulb.
Respect. It is better to disassemble the folded electric lancet from all the elements, including a voltmeter, and then connect it all the way through.
There are no different types of voltmeters with scales that vary. Therefore, I will add the information about calculating prices in this context and it is even more relevant. Even wider are microvoltmeters, millivoltmeters, simple voltmeters, etc. Behind their names it is clear what multiplicity they mean.
In addition, voltmeters can be divided into fixed and alternating instruments. If we want a constant flow at the same time, but at this stage of physics we are dealing with a constant flow, which is supplied to all galvanic elements, then we need the same voltmeters. Those that are used for the lanyards of the changeable strum are usually depicted on the dial by the appearance of a wilting line (Fig. 6).
Small 6. Voltmeter of the alternating strum ()
Respect. If we talk about voltage values, then, for example, voltage 1 is not a large value. The industry has much higher voltage values, which range in hundreds of volts, kilovolts and even megavolts. The voltage will be 220 or less.
In the future, we will find out that the conductor is so electrically active.
List of references
- Gendenshtein L. E., Kaidalov A. B., Kozhevnikov V. B. Physics 8 / Ed. Orlova U. A., Roizena I. I. - M.: Mnemosyne.
- Perishkin A.V. Physics 8. – M.: Bustard, 2010.
- Fadeeva A. A., Zasov A. V., Kiselov D. F. Physics 8. - M: Education.
Dodatkovi rrecommendations sent to Internet resources
- Physics is great ().
- YouTube().
- YouTube().
Home improvement
27.01.2016
Lesson 35 (8th grade)
Subject. Electrical voltage. Voltmeter
1. Electrical voltage, unit of magnitude, calculation formula
In previous lessons, we learned about the power of a current, and about the fact that this value characterizes the action of an electric current. We have already looked at a number of factors that lie in them, now we will look at other parameters that influence them. To do this, it is enough to carry out a simple experiment: connect one jerlo struma to the electric lancet first, then successively two more, and then three new jerels, at which point the power of the strum in the lancet will immediately subside. As a result of the dimming, a simple staleness will be visible: the strength of the stream increases in proportion to the number of jets that are connected. Why come out like that? The function of the jerela struma is to create the electrical fields of the lancet, apparently, the more that is included in series in the lancet dzherel, the stronger the electric field is created. From which one can go unnoticed, the electric field infuses the force of the stream into the lancet. In this case, when charges move along the conductor, an electric field is created, which means that the electric field determines the force of the electric field in the field.
On the other hand, one can imagine an analogy between the flow of electric current through a conductor and water through a pipe. If you are talking about the amount of water that flows through the cut of the pipe, you can compare it with the amount of charge that passes through the conductor. And the difference in height in the pipe, which forms the pressure and flow of water, can be compared with such concepts as electrical voltage.
To characterize the electric field of movement of a charge, the following quantity has been introduced, such as the electric voltage.
Electrical voltage is a physical quantity similar to the ancient processes of the electric field used to move a single charge from one point to another.
Appointment. voltage
One in the world. volt
The unit of voltage was named in honor of the Italian scientist Alessanro Volta (1745–1827) (Fig. 1).
If you point out a standard butt about the sense of the well-known writing of any household appliances “220 U”, it means that the Lanzug dealer has a 220 J power with a displaced charge of 1 C.
Small 1. Alessanro Volta
Formula for voltage reduction:
Work of the electric field due to the transferred charge, J;
Charge Cl.
So, one voltage can be measured like this:
Between the formulas for calculating the stress and force of the flow, there are interconnections, for which respect is given: i. In both formulas there is the magnitude of the electric charge, which can appear in color when the action is carried out.
2. Voltmeter
To adjust the voltage, use a device called voltmeter(Fig. 2).
Small 2. Voltmeter
There are different voltmeters based on the peculiarities of their operation, but the principle of their operation is based on electromagnetic activity. All voltmeters are designated in Latin letters, as they are marked on the dial of the device and are shown in the schematic diagram of the device.
In school minds, they use, for example, voltmeters, images of baby 3. It will help to measure the voltage in electric lances during the hour of laboratory work.
 |  |  |
The main elements of a demonstration 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. This is done to ensure that the terminals of the device are correctly connected to the conductor wires connected to the power supply. In place of the ammeter, which is connected to the lancet in series, the voltmeter is connected to the lancet in parallel.
Insanely, if any electric vibrating device is subject to minimal leakage on the lance, which is observed, then the voltmeter has such design features that through it there is a minimal flow. This effect can be ensured by selecting special materials that will ensure minimal charge flow through the device.
3. Voltmeter in electrical circuits
Schematic representation of a voltmeter (Fig. 4):
Small 4.
The lancet has a minimal set of elements: a heater, a frying lamp, a key, an ammeter, connections in series, and a voltmeter, connections in parallel to the light bulb.
The electrical circuit is imaginable for the butt (Fig. 5), in which it is connected 
voltmeter.
Respect. It is better to disassemble the folded electric lancet from all the elements, including a voltmeter, and then connect it all the way through.
When connecting the voltmeter to the lancet, it is necessary to adhere to the following rules:
1) press the voltmeter to the low points of the lancug, between which the voltage needs to be adjusted (in parallel with the line extension of the lancug);
2) the terminal of the voltmeter with the “+” sign is connected to the same point of the lancet section, which is connected to the positive pole of the dzherel struma, and the terminal with the “-” sign is connected to the point, which is connected to the negative pole of the dzherel struma.
If it is necessary to measure the voltage on the pump, then move the voltmeter directly to the mark (Fig. 31).
In other situations, for example, when the voltage on the lamp is lost, work as shown in figure 32.
4. Types of voltmeters
There are no different types of voltmeters with scales that vary. Therefore, I will add the information about calculating prices in this context and it is even more relevant. There are even wider microammeters, miliampermeters, just ampermeters, etc. Behind their names it is clear what multiplicity they vary.
In addition, voltmeters can be divided into fixed and alternating instruments. If we want a constant flow at the same time, but at this stage of physics we are dealing with a constant flow, which is supplied to all galvanic elements, then we need the same voltmeters. Those that are used for the lanyards of the changeable strum are usually depicted on the dial by the appearance of a wilting line (Fig. 6).
Small 6. Voltmeter
Respect. If we talk about voltage values, then, for example, voltage 1 is not a large value. The industry has much higher voltage values, which range in hundreds of volts, kilovolts and even megavolts. The voltage will be 220 or less.
Secured. Version of typical commands:
Zavdannya 1
The tile is turned on up to the lightening level. How much electricity flows through it in 10 minutes, since the power of the current in the cord that supplies it is more than 5A?
An hour for the CI system is 10 hvilin = 600s,
At higher levels, the strength of the stream is equal to that of up to an hour of charging.
I=q/t
Zvidsi, charge the old supply of power or stream immediately.
q = I t = 5A 600 s = 3000 C
Zavdannya 2
How many electrons pass through the spiral of the roasting lamp in 1 s at a lamp power of 1.6A?
The charge of the electron is older e= 1.6 10 -19 C,
The entire charge can be calculated using the following formula:
q = I t – the charge is more powerful than the current one.
The number of electrons equals the total charge to the charge of one electron:
N=q/ e
The star is burning N = I t / e= 1.6A 1s/1.6 10 -19 Cl = 10 19
Zavdannya 3
You will notice the voltage at the Lancug's point, since under the hour of passage on a new charge
in 15 Kl strumom bula vikonan robota in 6 kJ.
U = A/q = 6000 J/15 C = 400 St.
Zavdannya 4
When transferring 60 C of electricity from one point of the electric stake
inshu for 12 hv vikonan robot 900 J. Value of the voltage and force of the flow
U = A/q = 900 J/60 C = 15 V
I = q/t = 60 C/720 s = 0.08 A.
Home improvement:
1. V.V.Belaga, I.A.Lomachenkov, Yu.A.Panebrattsev. physics 8th grade, Moscow, “Osvita”, 2016. Read § 34 (p. 82-83).
2. Power notifications (usually).
2.1. The ammeter confirms that the inclusions at the lances in front of the light bulb show greater power below it. Are you a right student?
2.2. How can we determine the maximum force of the current that can be measured using an ammeter?
3. Unlock tasks:
3.1. What is the strength of the struma to pass 32 K through the transverse section of the conductor in 4 s?
3.2. Calculate the strength of the stream from the conductor, which passed a charge of 24 C for 96 g.
3.3. When an electric stream passes through a water source of acid, water is visible. What kind of electrical charge passes through the acid, which is the force of the stream 2 And the process of extracting the necessary amount of water takes 5 years?
4. Unlock tasks:
4.1. Calculate the amount of charge that passed through the conductor, if at a voltage of 36, the electric field generated 72 J.
4.2. Please note the price will be adjusted.
Slide 1
* 8th grade Electrical voltage. One voltage. Voltmeter. Voltage vibration 8th gradeSlide 2
* 8th grade Lesson goals. Introduce the concept of electrical voltage and the unit of voltage. Learn about the device for measuring electrical voltage - a voltmeter and its connections to the lancet. Develop logical thinking and memory 8th grade
Slide 3
* 8th grade Frontal training. What is the magnitude of the force of the strum in the lance? How does the force of the current flow through an electric charge? What should I take for one sili struma? What is this unit called? What subdivisions and multiples of unit ampere do you know? How is the electric charge expressed through the force of the current in the conductor at the time of its passage? 8th grade
Slide 4
* 8th grade What is the name of the device for vimiryuvannya or struma? In what units does the ammeter scale scale? How to turn on the ammeter in the Lanzug? Є accurate ammeter. How do you get around to it and change the scale to a different ammeter that has not yet been calibrated? 8th grade
Slide 5
* 8th grade Electrical voltage. Guess what, strum is a collection of charged particles: ions and electrons. The stench itself carries a charge. The ordering of the forces is created by the electric field, which prevents the robot from working. The work of the forces of the electric field that creates the electric struma is called the robot struma. What to lay there for? against a power stream (an electric charge that flows through a lance in 1 s) and not only that. Let's take a look at the background: 8th grade
Slide 6
* 8th grade Z little one can see that the power of the power supply is the same, but light bulb 2 burns brighter than light bulb 1. The power of the power supply, the pressure lies in addition to one physical quantity - electrical voltage. In our case, the voltage is adjusted by a straight line, less than the voltage, adjusted by a small electrical current. Voltage is a physical quantity that characterizes the electric field. Designation: U Units: 1V (volts) 8 class
Slide 7
* 8th grade Voltage shows how the electric field operates when a single positive charge moves from one point to another. 8th grade
Slide 8
* 8th grade One unit of voltage is taken to be the electric voltage at the ends of the conductor, which moves an electric charge of 1 C along this conductor equal to 1 J. 8th grade
Slide 9
Slide 10
* 8th grade Voltage control. To measure the voltage, use a special device - a voltmeter. Now you will have to come at the same time to the end of this plot of lantsug, where you want to keep the tension. The external appearance of a school demonstration voltmeter is shown to a right-handed child. 8th grade
Slide 11
* Class 8 Voltmeter connection. The voltmeter is connected to the electrical circuit in parallel. Press the voltmeter to reach the small points of the lantz, between which you need to control the voltage. 8th grade
Slide 12
* 8th grade Vibrates under tension on different sections of the Lanzug, which is formed by the rheostat of the light bulb. First, the voltage is measured on the rheostat: ... Then the voltage is measured on the light bulb: ... And, you will find, the voltage is on every connection ... The change shows what is in the light with the last connections of the conductors The voltage on all known sources is the voltage on the following conductors: 8th grade
Today we know one more physical quantity, but firstly give me a response to the question: When there is darkness in the light bulbs, what are we talking about?
(Voltage drops)
Topic: Electrical voltage. Voltmeter. Voltage reduction.
Repeatable and unforgettable:
- what is an electric strum;
- what is the electric field?
- What makes up an electric lance?
We know:
- what is the voltage?
- units of voltage;
- How to connect a voltmeter to the Lanc.
voltage at the edge;
Clash of the Titans of Physics
Name the electrical accessories Find the purpose
What is an electric strum? Know the reason for the electric flow.
What parts carry electric charge in metals?
Why is it so loud that these parts collapse?
About the strength of the struma, you can look at the ammeter readings, which is from the side of the struma (the more tension the thread is, the more force is added to the struma) Nutrition: what is the strength of the struma?
Evidence: the power of the strumu lies in any quantity associated with the string of the struma. The dzherelo struma is created by an electric field, which is created by robots from a distribution of electric charges.
Secondary light bulb and battery
Light bulb for gastrointestinal tract and battery
It’s clear why to deposit the robot struma
Electric voltage characterizes electric field, created by a stream. Voltage (U) shows yaku robot (A) current electric field when moving a single positive charge (q) from one point to another.Voltage =
One unit of voltage in the CI system:
U = 1V “Volt”
1 Volt is equal to the electrical voltage at the end of the lance, and when a charge is passed through, which is equal to 1 C, a robot operates, which is equal to 1 J:
Transfer to the CI system:
- 200 mV =
- 6 kV =
- 0.02 kA =
- 270 mA =
- 20th century =
- 2.1 MV =
2,100,000 V
Igor has a tight bag
- Don't like the electric fire!
RIGHT WHATEVER YOU CAN!
- The voltage, which is considered safe for people in a dry place, reaches 36 Art.
- For a simple addition, this value drops to 12 tbsp.
- When a person suffers from a blast that runs under a voltage of 240 V, the blast pierces the skin. If a strum flows along the mouth, the size of which is still lethal, but it is enough for one to get a fleeting bruise in the hand (the hand just “sticks” to the dart), then the support of the skin gradually changes, and through the strum reaches a deadly person in size 0 ,1 A. People who are stuck in such an unsafe situation need to help as much as possible, trying to “get through” the wire without causing any harm to themselves.
- Calibration "0"
- "+" to "+" "-" to "-"
- Switches on in parallel
- Umovne assigned
Vibrating under tension
Please indicate the price below:
- 2 V/ref
- 0.5 V/ref
The folding of the electric lance and the voltage changer
1. study the diagram of the electric lancet and select the struma directly
2. remove the electric lance, the key is to blame for the disconnection
2. Find “+” and “-” on the battery.
3. Look at the voltmeter and determine the price below
Find "0" on the voltmeter, guess how the voltmeter is connected
4. Call your readers to check the electric lancet
5. Only after the teacher allows you to close the key
see the voltmeter reading
6. Write down the readings of the voltmeter at the point
Task 1. When an electric charge of equal to 5 C passes through the conductor, the action is 200 J. Why is the voltage at the ends of this conductor equal? A) 1000 V B) 40 V) 40 A D) 0.025 V2. The voltage on the car light bulb is 12 V. What kind of charge passes through the filament of the light bulb, which means that the robot is 1200 J? A) 0.01 Kl B) 100 Kl U) 14400 Kl D) 10 V
3. Apply to the robot when a charge of 80 C is passed through the spiral of the electric stove, if it is connected to a voltage of 220 V A) 0.36 J B) 2.75 J C) 17600 J D) 0.36 V
5. Calculate the price of the Voltmeter section
A) 1 V B) 1.5 V) 3 V D) 15 V
4. It is necessary to measure the power of the current in the lamp and the voltage on it. How can I place the ammeter and voltmeter in relation to the lamp?
Lesson benefits:
Did we find out?
- what is the voltage?
- one voltage?
- What is the best way to vikorist for vimiryuvannya
- How do you need to connect a voltmeter to the Lanc?
what's the voltage at the edge?
Have you got the hang of it?
Home improvement
§39-41 Ex. 6 (2.3) Dodatkovo (for evaluation): 1264.1265 - Lukashik.
Flashlight When a flashlight hits, for example, a tree. It heats up, the water from it is vaporized, and the pressure of the steam that has settled and the gases that have heated up leads to a collapse. To protect against lightning discharges, install flash leads, which are a metal rod that rises above the object that is being protected. Bliskavka. In deciduous trees, the struma passes through the middle of the trunk along the core, where there is a lot of juice, which boils under the current of the struma and the steam bursts into flames of the tree. The reason is that there is no voltage difference between the cable and the bird that sits on it. Even if you’re sitting on something else without collapsing from the ground, you’re just sitting on one cable. In this manner, the voltage on the cable and the birds are completely avoided. If a rapt, flapping its wings, the same bird inadvertently bumps into the current cable, and also with another voltage, then the baking machine will respond... The reason lies in the fact that between the cable and the bird, which is sitting on the new one, it is not the fault of the voltage values Even if you’re sitting on something else without collapsing from the ground, you’re just sitting on one cable. In this manner, the voltage on the cable and the birds are completely avoided. If a rapt, flapping its wings, that same bird inadvertently bumps into the current cable, and then with another voltage, then the baking machine will spit... Fortunately, the cables are ready to be moved out at the same time Their dot is practically impossible. The threat to the lives of birds is negligible. Let God help you to verify this affirmation in practice.
Why do birds sit on high-voltage transmission lines?
Why do electrified people's hair rise up?- The hair becomes electrified with the same charge. Apparently, the same charges are formed, so the hair, like the leaves of a paper plume, diverges on all sides. If there is a body that can be held, including humans, isolated from the earth, then it can be charged to great potential. Thus, with the help of an electrostatic machine, a person’s body can be charged to a potential of tens of thousands of volts.
Thank you for the lesson! Good luck!
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 section, and when a charge equal to \(1\) C is passed through, the robot operates, which is more expensive \(1\) 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. Please label the signatures with a plus or a minus and, for clarity, 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.