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Technology

Grade 7

Electricity

Module 10

What is electricity?

Background

Electricity is a type of energy. An object has electrical energy when it has the ability to conduct electricity. Electricity is measured in Volts.

Electrical energy can be easily converted to other forms of electricity.

There are two main types of electricity:

  • main stream electricity
  • battery electricity

Battery-electricity

Electrical energy are stored in batteries. The energy in batteries are called chemical energy. When electrical energy moves, the electrons flows in an electrical circuit.

The basic elements of an electrical circuit is:

a source of energy e.g. a battery

Sketch Symbol

a conductor e.g. a sort of metal in the shape of a wire

Sketch Symbol

a switch to form an open or closed circuit

Sketch Symbol

a load e.g. a source of light, sound, motion or heat

Sketch Symbol
a light
a buzzer
an electrical motor

Two or more of the same component in an electric circuit can be connected in two different ways in the circuit;

  • in series where a positive pole of one cell is linked to the negative pole of another cell;
  • in parallel where all the positive poles of the cells are connected with one another and all the negative poles are also connected like this.

Advantage of cells in series – current supply becomes more powerful

Advantage of cells in parallel – the cells can produce the same current for longer.

To the teacher:

These worksheets should be done in groups. Each group can construct a different circuit and then explain it to the rest of the class before completing a worksheet. A class should be divided into 7 groups, because there are 7 worksheets. This would save a huge amount of time. Each group should construct a test circuit with a switch, 1,5 V lamp, lamp holder and a 1,5 V cell in a cell holder. First screw the holders and switch on the board, add the wire between them and then add the cell and lightbulb.

Equipment and tools needed:

  • 1,5 V batteries
  • 1.5 V light bulbs
  • light bulb holders
  • wire/flex
  • 7 strip connectors
  • battery holders
  • 7 switches
  • small screws
  • flat nose and star screwdrivers
  • 7 pieces of insulation board 150 mm by 150 mm
  • connectors
  • buzzers with a low voltage
  • diodes and resistors

Assignment 1:

To investigate by means of a simple practical test[lo 1.3]

To extract relevant data [lo 1.4.4]

To evaluate the system [lo 1.12]

To show knowledge and understanding of electric circuits [lo 2.2]

WORKSHEET 1:

  • Connect one 1,5 V cell in a battery holder to a 1,5 V lamp in a lamp holder with wire and a switch on a piece of insulation board.
  • Make a simple drawing of the circuit.

1.3 Draw a circuit diagram of the circuit, using the correct symbols.

1.4 Underline:

The light bulb shines (very brightly/bright/dimly/ not at all).

WORKSHEET 2:

2.1 Connect one 1,5 V cell in a cell holder to two 1,5 V lamps in two lamp holders in parallel using wire and adding a switch on a piece of insulation board.

  • Draw a circuit diagram of the circuit.
  • Unscrew one of the lamps from its holder. What happens to the other lamp? Explain why this happens.
  • Underline:

The light bulbs shine (very brightly/ brightly/ dimly/ not at all).

Questions & Answers

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Janga Reply
what is a cell
Sifune Reply
how is urine form
Sifune
what is antagonism?
mahase Reply
classification of plants, gymnosperm features.
Linsy Reply
what is the features of gymnosperm
Linsy
how many types of solid did we have
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what is an ionic bond
Samuel
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what is fallopian tube
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what is bladder
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what's bulbourethral gland
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urine is formed in the nephron of the renal medulla in the kidney. It starts from filtration, then selective reabsorption and finally secretion
onuoha Reply
State the evolution relation and relevance between endoplasmic reticulum and cytoskeleton as it relates to cell.
Jeremiah
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how is urine formed in human
Konadu
how is urine formed in human
Rahma
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malaria is caused by an insect called mosquito.
Naomi
Malaria is cause by female anopheles mosquito
Isaac
Malaria is caused by plasmodium Female anopheles mosquitoe is d carrier
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a canal is more needed in a root but a cavity is a bad effect
Commander
what are pathogens
Don Reply
In biology, a pathogen (Greek: πάθος pathos "suffering", "passion" and -γενής -genēs "producer of") in the oldest and broadest sense, is anything that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ. The term pathogen came into use in the 1880s.[1][2
Zainab
A virus
Commander
Definition of respiration
Muhsin Reply
respiration is the process in which we breath in oxygen and breath out carbon dioxide
Achor
how are lungs work
Commander
where does digestion begins
Achiri Reply
in the mouth
EZEKIEL
what are the functions of follicle stimulating harmones?
Rashima Reply
stimulates the follicle to release the mature ovum into the oviduct
Davonte
what are the functions of Endocrine and pituitary gland
Chinaza
endocrine secrete hormone and regulate body process
Achor
while pituitary gland is an example of endocrine system and it's found in the Brain
Achor
what's biology?
Egbodo Reply
Biology is the study of living organisms, divided into many specialized field that cover their morphology, physiology,anatomy, behaviour,origin and distribution.
Lisah
biology is the study of life.
Alfreda
Biology is the study of how living organisms live and survive in a specific environment
Sifune
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Source:  OpenStax, Technology grade 7. OpenStax CNX. Sep 10, 2009 Download for free at http://cnx.org/content/col11032/1.1
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