Electrical Energy

(Save-cents)

6.10 Save-cents

.10 Electric Energy Conversion

Find five electric appliances in each of the following groups.

List the watts (W) of power from the label

(If W is not listed Amps x Volts =W)(Volts is usually 120V)

Table 1 Appliances 200W or less

Table 2 Appliances (200W to 1000W)

Table 3 Appliances (over1000)

Appliance groups according to the energy conversion:

Group-1

Appliances which convert electric energy into the following: sound, domestic light, movement for light objects

Group-2

Appliances which convert electric energy into the following: mechanical work,(mixing, drilling, grinding…)

Group-3

Appliances which convert electric energy into the following: heating, cooling

 

6.20 Cost of Appliance Operation (A survey of energy use)

.21 Version-1

Calculations you must do to complete the table below

Complete the table below as follows:

1) Choose appliances you commonly depend on and find the power they use on the CSA label.

2) Gestimate the hours you use the appliance in one month

3) Do the calculations for kWh of energy used and the cost

Table: Electrical Appliances Work Sheet, p ____.

Example:

Also see Table: Electrical Appliances Work Sheet

720 h is used because the clock runs 24h/day 30 days/month

If you use the table, "Household Electrical Appliances", an average, "kWh", per month is already estimated and calculated. (Then you only need to do the second calculation, "Cost".

 

Table: Electrical Appliances Work Sheet

.20 Cost of Appliance Operation (A survey of energy use)

.21 Version-2

Calculations you must do to complete the table below

Complete the table below as follows:

1) Choose appliances you commonly depend on and find the power they use from the table, "Household Appliances"..

2) Gestimate the hours you use the appliance in one month

3) Do the calculations for kWh of energy used and the cost

Table: Electrical Appliances Work Sheet, p ____.

Example:

Also see Table: Electrical Appliances Work Sheet

720 h is used because the clock runs 24h/day 30 days/month

 

Use the table, "Household Electrical Appliances", an average, "kWh", per month is already estimated and calculated.

You only need to do the calculation, "Cost".

 

Table: Electrical Appliances Work Sheet

Household Electrical Appliances

Appliance

Power Watts

(W)

Energy kWh

(estimate for 1 month)

Blanket

180

10

Car Block Heater

400

36

Car Warmer

750

45

Clock

3

2

Clothes dryer

4500

80

Coffeemaker

900

6

Deep Fat Fryer

1500

75

Dehumidifier

350

75

Dishwasher

1500

30

Kitchen-Fan

75

8

Furnace -Fan

250

50

Chest-Freezer

340

70

Frost-free Upright-Freezer

375

110

Food Mixer

150

1

Fry Pan

1150

15

Sandwich-Grill

1180

3

Hair-setter

600

2

Hair-Blow Dryer

1500

11

Hair-Salon Dryer

1100

9

Heating Pad

65

15

Humidifier

70

30

Iron

1085

12

Kettle

1500

15

Kitchen Waste Disposer

375

2

Lamp (100W)

100

9

Lawn Mower

1000

10

Microwave Oven

1500

25

Radio

20

3

Range

12000

100

Range-Self Cleaning

12000

105

Refrigerator-Freezer-Manuel Defrost

400

50

Refrigerator-Freezer-Automatic

800

86

Refrigerator-Freezer-Frost-Free

900

104

Sewing Machine

100

1

Television-Colour

140

21

Television-Black & White

100

15

Toaster

1200

3

Vacuum Cleaner

500

3

Waffle Iron

1000

2

Washer- Automatic

350

5

Washer-Non-automatic

250

5

Water Heater

3000

400

Water Pump

250

23

These figures, originally supplied by an electrical utility were adapted by N.S.Dep. E.M.R.

 

.23 Cost of Appliance Operation, Energuide Labels

Can We Conserve Electricity Now?

 

 

 

The energuide program, introduced in 1979 by the Federal Government, helps the

consumer save money.

Large appliances, hungry energy users, require this label to inform the consumer.

The energuide label makes it easy to select the appliance which is less energy hungry. (indicated by the kWh per month on the label)

 

 

Assignment: Choose two appliances which do a similar job from the table , "Household electrical Appliances"

Calculate the energy saved by buying the less energy hungry one.

Example:

Range

100 kWh

 

Range (self- cleaning)

105 kWh

 

Saving per month

5 kWh

Saving over 20 year lifetime

Saving per year

60 kWh

1200 kWh x 9/ kWh =

$108

Your Turn, Complete the following:

     

 

 

______ kWh

 

 

______ kWh

Saving over 20 year lifetime

 

______ kWh

_______ kWh x 9/ kWh =

$_______

 

6.30 The Meter, your Electric Bill Monitor.

.31 The Meter How Many kWh do You Use?

 

Most meters will have four or five dials. The dials are numbered to measure the energy used. in kWh. The dial on the right measures units. The second , right to left measures tens of kWh the next hundreds ….

The electric meter dials are read starting with the dial at the right The needle points out a number. If the needle is between two numbers take the lower number as the reading. If the needle is between 0-9. this zero is read as a 10 so 9 is the number to record.

Notice only every other dial is numbered clockwise. Be sure to check the direction of the increasing numbers before you read the dial.

Notes:

1) Some meters are designed with a multiplier . This is stamped on the face of the meter. In this case multiply by your reading by the number stamped on the face, i.e. x10.

2) Electric utilities sell energy in kWh not Joules 1kWh =3.6MJ or 3,600, 000 J ( A watt is the energy used in 1 sec therefore 10KWh is the energy used by a 10W appliance in one hour )

.32 Meter Reading

The first meter reading is 4 982 kWh

a)What does the second meter read? ____________

b)How many kWh of electricity were used from June 20 to Aug 20?

________________________________________________

Did you get the following answer?

Amount of energy used = 6 472 kWh - 4 982 kWh = 1490 kWh

Student Assignment-1

Read these meters. Record the reading under each dial.

Student Assignment-2

Draw the hands on the meters for the numbers under the dials.

.33 Cost Read From the Meter: Student Assignment-3

Read your meter as follows:

[1] Record the date: Day /Month/ Year/time:___/ ___/ ___/ ___

[2] Record the position of the dials on the diagram , "Initial Reading" Underneath the dials record the number read.

"Initial Reading"

[4] Wait two or three days.

Record the position of the dials on the diagram , "Final Reading" Underneath the dials record the number read.

"Final Reading"

[5] Subtract the readings.

[6] Multiply the kWh by 9 to find the cost of electricity.

[7] Divide by the cost number of days between the readings.

(Find an electric bill and check to see if your calculations are in agreement with your electric bill .( Check and see some electric bills are for either 60 or 30 days of energy use)

.34 Word Search from Science +3 p 204 (Work Sheet)

WORD SEARCH

First, identify each word from the clue given, then search for the word in the puzzle. Circle the word as you find it. A letter may be used more than once. When you finish the letters left over will spell the last clue[24]

Have Fun!

[1] A flow of electrical charges through a conductor ________________

[2] A devise in which electrical energy is generated from heat ______________

[3] When a __________ is moved near or into a coil of wire a current flows in the coil.

[4] A current-bearing coil of wire surrounding an iron core makes a(an) _____________

[5] Two different metal plates in an electrolyte convert ___________ into electrical energy.

[6] In a solar cell, electrical energy is produced from ____________ energy.

[7] A long-lasting miniature cell used in the heart of pacemakers ______________

[8] A cell which the electrodes can be recharged by electricity ______________

[9] In a car battery the electrodes are often made of ____________ and an oxide of this metal.

[10] A long life cell made of zinc and magnesium electrodes. _________________

[11] If a wire forming a complete path moves between the poles of a magnet and increases in speed, __________ current is produced.

(no more , less, the same )

[13] A _______________ is a device used to convert mechanical kinetic energy into electric energy on a large scale.

[14] The resistance of a wire is greater if it is ________________ and ______________

[15] Copper has ______________ resistance (than,as)nichrome.

(no more , less, the same )

[16]In a circuit, if lamps are hooked up in _____________, all will go out when one burns out.

[17]In the arrangement "A" below ________________, current will flow through each lamp,

(greater, smaller, similar) compared with arrangement "B".

[18] Arrangement "B" is __________________

[19] When electrical energy changes to another form of energy, ___________ energy is always produced.

[20] Unit in which the potential energy of a cell or battery is measured. ___ /____= ____

[21] A battery or cell gives _____________ energy to electrons.

[22] If part of a circuit is short circuited, the current in this short circuit will __________

(stop, increase, decrease)

[23] Safety devise in a circuit. _____________________.

[24] "Fluorescent Lights", in the sky lit up by charged particles from outer space. (Northern Lights)