Sources of Electric Current

1.0 Electric Energy can be converted from the following:

1.10-Chemical Energy in Cells.

.12 Electricity From a dry cell

Set up the experiment as shown. pp136

 

Word list:

metal electrodes

ammonium chloride

negative

electrolyte

zinc

copper

ammonium chloride

more

electrical

Complete the sentences from the , "Word List"

a) In a dry cell, chemical energy is changed into _____________ energy.

b) A cell for making a current always consists of two different _____________ and an _____________

c) A dry cell can be made using the two metals ____________ and ____________, and a solution of _____________ placed on blotting paper.

d) Two dry cells produce _____________ current than one cell

e) When you connect two cells to make a battery the positive electrode of one cell is connecter to the _____________ electrode of another cell.

You might enjoy reading about Michael Fariday pp 200 in the book

 

.13 Your Turn with A Dry Cell

Make a Dry cell using the following:

metals like: pennies(copper) nickels (nickel), gum-wrap foil …

electrolytes like: lemon juice and salt; washing soda solution,; baking soda and salt; dish washer detergent; …

Paper towel, blotting paper, or construction paper will do to soak your electrolyte in.

Note: All metals must be brightly cleaned.

Arrange the metals in alternate layers

Place electoylte soaked paper between te metal layers as shown.

in the diagram below.

Diagram

 

Typical voltage 1-2V current ______? milliamps

Try your cell; can it run a luiquid crystal digital clock? For how long?

Have a contest!, Evaluate each others work.

Here is an opportunity to make a project and do some research. A question to get you started on your investigation might be, "Which metal pairs and electrolyte work best?"

Remember to do the following:

control variables, manipulate only one variable at a time and the responding variable, "work best", must be defined so we know how you measured which was best. Present your findings and display all tools used in the investigation.

 

The following diagram will help you with connections to measure voltage and current.

Two possible Evaluation: forms follow:

 

 

Form-1

 

Name/Section _________________

Evaluated Item

Peer Evaluation

( circle one)

 

Dramatic value (workmanship)

1 3 5 7 8 9 10

 

Runs a digital clock

2 4 6 7 8 9 10

 

Originality of design

1 3 5 7 8 9 10

 

Ease of use (connection)

1 3 5 7 8 9 10

 

Stability of current

1 3 5 7 8 9 10

 

Overall design superiority

1 3 5 7 8 9 10

 

Total Mark

   

 

Form-2:

 

Experimental Project Evaluation

Adapted from a Judging Form

Source: Youth Ssience Foundation of Canada

Name: __________________

Section: ________

 

"Experiment Type Of Project" - An investigation undertaken to test a specific hypothesis using Experiments.

Part A: Scientific Thought (maximum 45 marks)

 

Level 1

Duplicating of a known experiment to confirm the hypothesis (totally predictable).

 

15 Marks Mandatory (Max. 25/45)

 

+ 1 2 3 4 5 6 7 8 9 10

 
     

Level 2

Extend a known experiment through modifications of procedures, data gathering and application.

 

25 Marks Mandatory (Max. 35/45)

 

+ 1 2 3 4 5 6 7 8 9 10

 
     

Level 3

Devise and carry out an original experiment with controls. Variables are identified. Some significant variables are controlled.

 

 

35 Marks Mandatory (Max. 45/45)

 

 

+ 1 2 3 4 5 6 7 8 9 10

 

 

Answers: .12-Electricity From A Dry Cells.

 

Word list:

a) electrical

b) metal electrodes

b) electrolyte

c) zinc

c)copper

c) ammonium chloride

d) more

e) negative

 

 

 

Complete the sentences from the , "Word List"

a) In a dry cell, chemical energy is changed into _____________ energy.

b) A cell for making a current always consists of two different _____________ and an _____________

c) A dry cell can be made using the two metals ____________ and ____________, and a solution of _____________ placed on blotting paper.

d) Two dry cells produce _____________ current than one cell

e) When you connect two cells to make a battery the positive electrode of one cell is connecter to the _____________ electrode of another cell.

 

..14 Electricity From a Wet Cell

Set up the experiment as shown. pp183

 

 

Word list:

decreases

electrical

zinc

electrolyte

chemical

copper

different

dilute sulphuric acid

increases

gas

Complete the sentences with the, "Word List"

a) A cell converts _____________ energy into _____________ energy.

b) A wet cell consists of two _____________ metals and a ___________

c) A wet cell may be made using the two metals _____________ and ___________ and the chemical _____________.

d) As more of the metal strips are covered with solution, the amount of current produced _____________

e) As the current continues to flow, _____________ may be produced around the electrodes.

f) During the opperation of the cell, the current _____________ because bubbles insulate the electrode from electrolyte contact

 

 

 

Answers:.14 Electricity From a Wet Cell

 

Word list:

a) chemical

a) electrical

b) different

b)electrolyte

c) zinc

c) copper

c) dilute sulphuric acid

d) increases

e) gas

f) decreases

Complete the sentences with the, "Word List"

a) A cell converts _____________ energy into _____________ energy.

b) A wet cell consists of two _____________ metals and a ___________

c) A wet cell may be made using the two metals _____________ and ___________ and the chemical _____________.

d) As more of the metal strips are covered with solution, the amount of current produced _____________

e) As the current continues to flow, _____________ may be produced around the electrodes.

f) During the opperation of the cell, the current _____________ because bubbles insulate the electrode from electrolyte contact.

 

 

 

1.20 Light energy in Solar Cells.

Set up the experiment as shown. p 138

 

 

Word list:

smaller

larger

electrical

light

Complete the sentences with the, "Word List"

a) A Solar cell converts _____________ into _____________ energy.

b) If the light is brighter you know there is a _____________ in the amount of current.

c) If the light is moved away from the cell the current is ____________

 

 

Answers:.1.20 Light energy in Solar Cells.

 

 

Word list:

a)light

a)electrical

b)larger

c)smaller

Complete the sentences with the, "Word List"

a) A Solar cell converts _____________ into _____________ energy.

b) If the light is brighter you know there is a _____________ in the amount of current.

c) If the light is moved away from the cell the current is ____________

 

1.30 Magnetic energy in a Coil of Wire

Set up the experiment as shown. p139

 

 

Word list:

electrical

current

magnet

opposite

increased

moved

coil

Complete the sentences with the, "Word List"

a) A magnet moving in or out of a wire produces a _____________ .

b) When a magnet is thrust into a coil, the current goes in one direction: when the magnet is removed, it goes in the _____________ direction.

c) If the speed of the moving magnet is increased the current is _____________

d) The kinetic and magnetic energy of the moving magnet is changed into _____________ energy.

e) A current occurs in a wire coil if the coil is _____________ over a stationary _____________.

 

 

 

Answers:1.30 Magnetic energy in a Coil of Wire

Set up the experiment as shown. p139

 

 

Word list:

a)coil

a) current

b) opposite

c) increased

d) electrical

e) moved

e) magnet

Complete the sentences with the, "Word List"

a) A magnet moving in or out of a wire produces a _____________ .

b) When a magnet is thrust into a coil, the current goes in one direction: when the magnet is removed, it goes in the _____________ direction.

c) If the speed of the moving magnet is increased the current is _____________

d) The kinetic and magnetic energy of the moving magnet is changed into _____________ energy.

e) A current occurs in a wire coil if the coil is _____________ over a stationary _____________.

 

 

1.40 Heat energy in a Thermocouple

Set up the experiment as shown. below:

Diagram:

 

 

Word list:

greater

electrical

heat

Complete the sentences with the, "Word List"

a) In a thermocouple, _____________ energy is converted into _____________ energy.

b) The greater the difference in the temperatures of the two connections, the _____________ the current.

 

Answers: 1.40 Heat energy in a Thermocouple

 

Word list:

a)heat

b)electrical c) greater

 

Complete the sentences with the, "Word List"

a) In a thermocouple, _____________ energy is converted into _____________ energy.

b) The greater the difference in the temperatures of the two connections, the _____________ the current.

 

 

1.51 Magic Square

2 metals

3 brightness

4 moving magnet

5 electrolyte

(solution)

6 light

7 no

8 different

9 chemical

10 compass

needle

11 positively

12 thermocouple

13 battery

15 negatively

16 magnet

17 opportunely

charged

18 more

A current of electric charges flowing in a wire acts like A (magnet-16) and will cause a(an) B______________ to move. The opposite effect is obtained when a current is produced in a coil of wire by C______________ .

If you want to make electrical energy from D______________ energy, you can use a cell. a cell has two E______________ metals and an F______________

These metals cause charged particles called electrons to leave one metal G______________ charged while making the other metal H______________ charged.

Two attached cells form s(an) I______________.

When cells are connected, an electrode of one cell is connected to the J______________ electrode of the other cell.

A solar cell converts K______________ energy into electrical energy. More electrical energy can be obtained by increasing its L ______________.

If two different M______________ are connected in the form of a loop, and the connections are placed in ice, N______________ current will flow. If one connection is placed in ice and the second connection is placed in, O______________ electricity will flow than if the second connection were at room temperature . This arrangement of metals is called a (an) P______________. It is an energy converter changing heat energy into electrical energy.