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Lesson type: lesson on building a knowledge system

Lesson type: integrated – connection between physics and life safety.

Purpose of the lesson:

1. Repeat and update the studied material in a non-traditional entertaining form.
2. Learn to apply knowledge in a new situation.
3. Form an idea of ​​the dangers of electric current.
4. To develop teamwork skills in combination with independent activity of students.
5. Develop interest, the desire to penetrate into the essence of phenomena, a vision of the significance of the studied material.

Lesson Objectives:

• Educational: repeat and consolidate the basic laws, develop the skill of solving qualitative and experimental problems.
• Developmental: development of cognitive motivation, logical thinking, development of the regulatory sphere based on self-control and mutual control.
• Educational: education of personal qualities: activity, passion, intelligence.

Planned results: Students will learn to apply the acquired knowledge in practice, process the information received, and draw conclusions as a result of joint work.

Resources: textbook, notebook, current source, ammeter, voltmeter, light bulb, wires, key.

Equipment: computer, smart board, chalkboard.

Organization of space: frontal work, group work, pair work

Lesson progress

I. Organizational moment. Motivation for learning activities.

Today will be interesting
Not boring at all, not bland at all!
What is the source of your interest?
Important topic: “Electric current”

II. Updating knowledge. Slide show.

"Lightning", "Power Line"

– Tell me, guys, what do these slides have in common?

– Electric current

III. Setting the lesson topic.

Electricity everywhere
Both on land and in water.
It even happens in space!
And the atmosphere is “rumbling”!
Everyone knows about the benefits of electricity
But they forget about the danger!

– Guys, formulate the topic of today’s lesson.

– “Useful and dangerous electric current»

– Who can formulate the main goal of our lesson?

– Find out the benefits and dangers of electric current.

IV. Repeat e.

1. What is electric current?

– Electric current is the directed movement of charged particles.

2. Conditions for the existence of email. current in the circuit?

– Presence of a current source, presence of charged particles.

3. Where is electricity generated? current?

– At thermal power plants, hydroelectric power plants, nuclear power plants, unconventional power plants

4. Basic laws of electric current?

– Ohm’s law, Joule-Lenz’s law, laws of series and parallel connection of conductors.

5. What devices measure current and voltage?

– Ammeter, voltmeter

6. Where is electrical energy used?

– In everyday life, in transport, in industry

7. What device allows us to determine the amount of energy consumed?

– Electric meter

V. Checking homework.

- Guys, now let's check your homework.

1. How did you determine the consumption and cost using the meter? electrical energy in your apartment in 5 days?

The teacher checks the written homework. Discusses with students who uses energy sparingly.

2. Guys, you had a task: find ways to save electricity in additional literature. Let's discuss and reflect together.

VI. Application of acquired knowledge in a new situation (presentation: “Saving energy”).

Now I will show slides with the advice of a young physicist, and we will discuss these tips and draw up a reminder on saving electrical energy.

Basic rules for saving energy

1. Install a two-tariff meter.
2. Replace incandescent lamps with energy-saving ones, and wipe off dust from light bulbs more often.
3. When leaving, turn off the light.
4. Turn off devices that are in standby mode.
5. Use Class A electrical equipment.
6. Place the refrigerator in the coldest place.
7. The stove must be in good working order. The container must have a lid and fit tightly to the heating elements.
8. Boil water in a clean, lime-free kettle

– We know that electricity serves people and therefore we must save energy. Electric current represents and great danger for humans

Solving experimental problems

Guys, we discussed the rules for safe handling of electric current. Let's experiment with measuring instruments and we will include them in the electrical circuit, breaking the rules.

Each group receives a task and equipment. Students perform an experiment, draw conclusions, write down, and answer.

Task 1.

When measuring the current in a light bulb, a student mistakenly turned on a voltmeter instead of an ammeter. What happened?

Answer: the light bulb did not light up, almost all the voltage was on the voltmeter, which has a high resistance

Task 2

When measuring the voltage on a light bulb, a student mistakenly turned on an ammeter instead of a voltmeter. What happened?

Answer: a very large current has arisen, which can lead to damage to the ammeter, so it is necessary to quickly turn off the ammeter (a short circuit has practically occurred, since the resistance of the ammeter is low).

Summing up the lesson: the teacher evaluates the work of the class and individual students, the students answer what they learned in the lesson.

1. Learned the rules for saving energy.
2. Rules for safe handling of electricity on the street and at home.
3. Rules of conduct during a thunderstorm.
4. We repeated the basic formulas.
5. Solved quality problems.
6. Performed experimental work.

VII . Homework information.

ensuring children understand the purpose, content and methods of completing the task

VIII. Reflection.

Students stick a green piece of paper on the board if they understand the topic; if you don’t understand, red; if you didn’t understand enough, yellow.

Slide 1

The effect of electric current on a person.
Completed by: 9th grade student Yulia Bakovskaya Checked by: physics teacher L. V. Tsipenko, 2011

Slide 2

How does electric current affect a person?
The fact of the effect of electric current on a person was established in last quarter XVIII century. The danger of this action was first established by the inventor of the electrochemical high-voltage voltage source V.V. Petrov. The description of the first industrial electrical injuries appeared much later: in 1863 - from DC and in 1882 - from variable.

Slide 3

Electrical injuries are characterized by the following features: the body’s protective reaction appears only after a person comes under voltage, i.e., when the electric current is already flowing through his body; electric current acts not only in places of contact with the human body and on the path through the body, but also causes a reflex action, manifested in disruption of the normal activity of the cardiovascular and nervous system, breathing

Slide 4

There are two types of electric shock to the body: electrical injuries and electrical shocks.
Electrical injuries are local damage to tissues and organs: electrical burns, electrical marks and electroplating of the skin. Electrical burns occur as a result of heating human tissue by an electric current flowing through it with a force of more than 1 A. Burns can be superficial when they are affected skin, and internal - when deep-lying tissues of the body are damaged. According to the conditions of occurrence, contact, arc and mixed burns are distinguished.

This presentation introduces students to safety rules when handling electricity and electrical appliances, and warns against accidents at home.

View document contents
“Lesson on life safety. Selivanova”

Life safety lesson

Selivanova Svetlana Anatolyevna

Primary classes

"Electricity"

Target:

Familiarization of students and pupils with the rules for using electrical appliances.

Tasks:

Expand students' knowledge about the variety of electrical appliances used in everyday life.

Familiarize yourself with the rules for using electrical appliances.

Develop logical thinking.

Develop skills in working with information.

Progress of the lesson

Conducting the experiment.

If you rub a pencil on a piece of woolen fabric, then bring it to small pieces of paper placed on the table, you will see.... What is this phenomenon?

(action of electricity)

Subject message.

The word "Electricity" - Greek word and means amber. Even in ancient times, the Greek mathematician Thales had an idea about electricity. By rubbing the amber stick on the wool, he seemed to charge it with static electricity. When brought to the head, this stick attracted the hair. We received such electricity ourselves.

But this electricity is called static because it only accumulates in various subjects. It cannot be transmitted over a distance and cannot be used in lighting fixtures.

Later, scientists found that electricity is a flow of tiny charged particles - electrons. Each electron carries a small charge of energy. But when there are a lot of electrons, the charge becomes large and appears electrical voltage. This is why electric current can travel through wires long distance.

Independent work in groups. Find the answer to the question:

How does electricity get to your home?

Story(handout on tables)

To transmit electricity where it is needed, power lines are built. You, of course, saw tall pillars behind the settlement - supports, to which the wires are suspended. Through these wires, electricity from power plants comes to different cities and towns.

Electricity flows through wires at very high voltages, reaching hundreds of thousands of volts.

So that no one can even accidentally touch the wires, they are suspended high in the sky on special supports. To prevent lightning from striking the wires, a special wire is hung above them - lightning rod

You can see it at the very top of the support.

When electricity comes into the city through wires, it reaches electrical substation. There is a special car there - transformer.

Never touch a cable that is sticking out of the ground because it may carry high voltage!

Electricity comes through cables to a transformer box, which is located near the houses in your locality. The small transformer inside lowers the voltage even further, so that the electricity can now be used in various appliances in your home.

How does electricity get to your home?

Why are the supports made so high?

What rule did you learn while reading the story?

(Discussion.)

What appliances in your home can use electricity?

Crossword "Electrical appliances"

Only me, only me

I'm in charge of the kitchen.

Without me, no matter how hard you work,

Go without lunch. (electric stove)

He willingly inhales dust,

Doesn't get sick, doesn't sneeze. (vacuum cleaner)

On the table, in the cap,

Yes in a glass bottle

A friend settled in -

Cheerful light. (lamp)

Look at my barrel

The top is spinning inside me,

He doesn't hit anyone

The cream will quickly run off on you. (mixer)

They pull from each other

Not the radio, but says

Not a theater, but a show. (TV)

Which keyword did it work? (dangerous)

When you press the switch of a lamp or any device, the electric current coming from the generator begins to flow through the wires and the device begins to operate, and the light bulb begins to glow.

When the wires are faulty, the electricity becomes dangerous. A person may accidentally touch a bare wire and receive an electric shock. Wires can become connected and cause a short circuit or even a fire.

Therefore, if you see a bare wire or a faulty switch or socket, immediately tell an adult about it.

Everything that runs on electricity must be in good working order!

If there is a burning smell from the TV or vacuum cleaner, or if sparks are visible, you must immediately unplug the wire from the socket. This device needs to be repaired.

Can you repair faulty electrical appliances yourself?

You need to know how to handle electricity!

What should you never do?

Remember, electricity does not like being near water.

Discussion of pictures on slides. (We draw our own conclusions)

There are several electrical appliances on the table.

Look at them carefully and determine which electrical appliances cannot be used.

(discussion)

Bottom line.

Let's repeat once again what are the rules for using electrical appliances.

What have we learned about electricity?

Why is it dangerous? How to avoid disaster when interacting with electricity?

Reflection

Today in class I (me)….

View presentation content
"electricity.Selivanova"

MS(K)OU "B-Usinsk special (correctional) boarding school of 8 types"

Primary classes

S.A. Selivanova




How do electrical appliances work?

I run along the paths, I can’t live without a path. Where am I, guys, no light in the house? To distant villages, towns Who is walking on the wires? Serene Majesty This is ELECTRICITY!

The murmuring water in the river flows,

Electric current flows through the wires.

He walks, runs, flies to our aid

Cook dinner, vacuum the floor, sofa.




Electricity is supplied to electrical appliances using a socket and plug




IRON

Strokes everything it touches

And if you touch it, it bites.

A very necessary friend in life -

Electric iron!




The dry wind dries out my mother's curls.




FRIDGE

Admire, look:

North Pole inside,

Snow and ice sparkle there,

Winter itself lives there.

Forever this winter for us

Brought from the store.




ELECTRIC KETTLE

It boils from the inside and blows bubbles.

Enjoy the evening with deliciously brewed tea!




TELEPHONE

He runs along the wires -

You say here

And you can hear it there.




TV

I look at the screen in the apartment, And I see what is happening in the world.

Weather, news, cinema,

I’ll learn about sports at the same time.




WASHING MACHINE

Item required

we have it, it works quietly,

it pleases the eye. It will save time

and saves your hands - Washing machine

will save us from worries!




VACUUM CLEANER

We have a robot in our apartment -

He has a huge trunk.

The robot loves cleanliness

And it hums like a liner: “Too-oo.”

Eagerly swallows dust,

But he doesn’t get sick, he doesn’t sneeze.




ELECTRIC STOVE

Four red suns

I have it in my kitchen

Four red suns

They burned and went out.

Borscht, pie, pancakes are ready.

No need for sun until tomorrow.




MICROWAVE BAKE

Cook quickly, deftly -

Need a microwave. Ring! Here's some delicious food

Cooking quickly, without difficulty!




TAPE RECORDER

My friend is with me

lives nearby.

You press the button -

and he will sing a song.




FAN

With this fast propeller He gives us a fresh wind! And the air will become fresher for all people, for all children!




Solve the crossword puzzle




Doesn't like electricity:

METAL

ITEMS






• Look carefully at the drawing.
• Draw a conclusion.



• Do not use faulty electrical appliances.
• You cannot repair or disassemble electrical appliances yourself.
• Do not pick at the socket with your finger or other objects.
• Do not turn on electrical appliances with wet hands.
• Do not touch exposed wires.


• Today in class I (me)….



"Bus Hijacking" - Religious terrorists use violence for purposes that they believe are divinely ordained. Hamas. Al-Qaeda. Religious terrorists. The story of the kidnapping of children thundered throughout the country. Nationalist terrorists. Hezbollah. El Jihad. Types of terrorism. Aum Shinrikyo. Terrorist acts. The story of the kidnapping of children.

“Poisonous plants” - Poisoning with crow’s eye berries causes nausea, vomiting, and abdominal pain. The hemlock stem is covered with a bluish coating and red-brown spots. Anchar is a very tall (up to 40 m) tree. People poisoned by henbane become violent. The height of wild rosemary is 50-120 cm. Henbane, even in small doses, can be toxic.

“Dangerous plants” - May lily of the valley (the berries are dangerous). Cassia (all parts of the plant are dangerous). Philodendron (all parts of the plant are dangerous). Lantana (all parts of the plant are dangerous). Adenium obese (lacty juice is dangerous). Browallia (all parts of the plant are dangerous). Tulip bulbs. Aglaonema (all parts of the plant are dangerous, cell sap is poisonous). Cineraria is a ragwort (all parts of the plant are dangerous).

“Stranger” - Don’t linger on the way home from school. Life and health are more valuable than any thing. Don't engage in conversation with a stranger. What should you do on the street to avoid becoming a victim of crime? When approaching the house, look around and have your keys ready in advance. When leaving the house, securely lock the windows and doors. Don't play outside after dark.

“Rules of behavior on the water” - Municipal Educational Institution Secondary School in the village of Sofiyskoye. Rules safe behavior on the water. Life safety teacher Elena Leonidovna Yakovleva. Use of life-saving equipment. One of the main reasons is the inability to swim, the inability to stay on the water. Basic rules of conduct when swimming. Be careful when approaching a drowning person. Safety measures when operating watercraft.

“Ice strength” - If after 2-3 hits with a stick on the ice no water appears, then the ice is reliable. Rules of conduct on ice. The size of the ice under a single pedestrian with a load is at least 7 cm. If the victim is conscious, give him hot tea or coffee. It is not advisable to walk on ice in the dark. Do not approach anglers closer than 3 meters.

There are 8 presentations in total

1 slide

Electrical Hazard Analysis Diagrams electrical networks ZNT INT ZNT - network with a grounded neutral point of the transformer; INT - network with an isolated neutral point (NT); (0 - 0) - neutral protective conductor; R0 - working grounding of NT; Ri is the phase insulation resistance relative to ground; C - capacity; Ul - linear voltage (380V); Uph - phase voltage (220V).



2 slide

Dangerous situations electric shock 1. Accidental two-phase or single-phase contact with live parts. 2. Approaching a person at a dangerous distance to high-voltage buses (according to regulations, the minimum distance is 0.7 m.) 3. Touching metal non-current-carrying parts of equipment that may become live due to insulation damage or erroneous actions of personnel. 4. Getting under step voltage when a person moves through the zone of current spreading from a wire that has fallen to the ground or short circuit of live parts to the ground.



3 slide

Two-phase touching live parts The most dangerous case is touching two phase wires (a) and the phase and neutral wire(b). Current Ich passing through a person and touch voltage Upr (V) with human resistance Rch (Ohm): Touch voltage is the potential difference between two points in the circuit that a person touches with the surface of the skin. Current path - “hand-to-hand”



4 slide

Single-phase touch to the network with ZNT This case is less dangerous than two-phase touch, since the resistance of the shoes Rob and the floor Rp is included in the damage circuit. R = Rch+ Rob+ Rp Damage chain: Networks with ZNT are used in enterprises, cities, and rural areas. Current path - “arm-leg”



5 slide

Single-phase contact with a network with an INT This case is less dangerous than for a network with a ZNT with normal insulation resistance Ri (Ohm), but the danger for a long-distance network may increase due to the presence of capacitive current. With the same R and each phase, the total insulation resistance is equal to: Networks with INT are used for short lines. They require constant monitoring of R and. Current path - “arm-leg”