Force of current. Ammeter

Разделы: Физика, Иностранные языки


Subject: term: date: form:
Physics 3   8
Theme: Electric current. Ammeter.
Resources:
  • Physics
  • Presentation
  • Electric equipment: ammeter, wires, bulb, switch
  • Test
Aims:

1. Educational: revise terms electric current, current sources, construction and principle of work of the current source know symbols of electric circuit, know rules of making the circuit

2. Developing:

  • develop the ability to work with electric material.
  • develop problems solving skills
  • develop logical, thinking, and intellectual abilities:

3. Educative: enlarge students’ outlooks; acquire a habit to work individually, and in groups.

Learning outcome:

Students

1. know current;

2. make a circuit experimentally;

3. solve problems

4. know how to work individually;

Core information:

Symbols of circuit, current I=q/t, ammeter

Презентация

PLAN

Stage Time Teacher’s actions Students’ actions
Org. Moment 1' Greetings

Divide students into three groups according to the color of a paper students take from the box.

Students take a colored paper from the box and sit at the table relatively
Warm up 5' 1. Shows terms on the board:

Электрический ток

  1. Направление электрического тока
  2. Постоянный и переменный ток
  3. Источники тока
  4. Действие электрического тока
  5. Электрическая цепь
  6. Напряжение
  7. Положительный и отрицательный электрические заряды
Translate terms

Electric current

direction of electric current

direct and alternating current

sources of electricity

effects of electric current

Electric circuit

Voltage

Positive and negative electric charge

Revision   Tells the task: “You have a list of questions and 2 minutes for preparation. Your teams will answer one by one, but every next answer should be given another student in the team” Appendix 1

Describe the figure.

Fill in the gap.

Electric current is the motion of electrons

Electric circuit is a source of electricity, wires and devices

Current may be of two types: direct and alternating.

4.What effects of electric current do you know?

5. What are conditions for current in a circuit?

6. Tell about unusual electric source. (Lemon or salty cucumber)

 

Students describe the figure

Students write on the board

Students’ answer:

Heat, physiological, magnet and chemical

Students’ answer:

Free electrons, source of electricity, electric field

Describes the source of electricity based on lemon. Zink plate (wide) and carbon rod are connected to the ammeter. They are put inside the lemon. The pointer moves and shows current in a circuit

Checks the correctness of task after each exercise  
Main part 35' Current

Presentation of the theme.

Force of current is the amount of charge passing through a point in the circuit in one second.

I - Force of current (A)

q – Charge (C)

1t – time (s)

Caution!

1A is dangerous for life!

Ammeter is the device for measuring current

Write information
2. Asks students to draw and make a circuit in groups using bulb, wires,ammeter,switch.

Make a circuit experimentally
3. Solve the problem

Solve these problems on the A3 papers and stick them to the board

1.Find force of current in electric bulb, if electric charge of 300C travels through it during 10 min.

2.What charge will travel during 3min through ammeter if force of current is 0.2A?

3.Force of current is 200A. What is the time the charge of 60000C travels through it?

4.Force of current in the iron is 0.2A. What charge will travel through it during 5 min?

4.Self – checking test

Look at the board, teacher reads question from the slide, students write answers in the exercise-book. After writing the test they take neighbor’s exercise-book and check it with the red pen

Students solve problems in groups and stick them to the board (they use colorful markers and write with large letters )

The contrary groups check solutions

 

 

 

 

Students fulfill the test and check themselves

Test:

Force of current is...

Ammeter is...

What circuit is correct?

A charge of 3.6*104C passes through a bulb in 1 hour. What is the force of current passing through the bulb?

An amount of 1020 electrons pass through the cross section of a wire in 8 s. What is the current passing through the wire? (take e=1.6*10-19C)

Answers: 1b.2c.3c.4a.5c

 
Home Assignment 1' # 36 ex14 #1.2.3.4 (wr)
Giving feedback and assessment 3' Today we have revised terms electric current, current sources. Also we have made a circuit and we can solve problems on the theme “Current”

You did a good job!