The Cost of Using Electrical Appliances at Home
To know the cost of using electrical
appliances.
•
List as many electrical appliances in your
home as you can.
•
How can we work out how much they cost?
To know the cost of using electrical
appliances.
Success criteria-
State what factors affect the cost of using
electrical appliances.
Calculate the energy transferred by an
electrical appliance.
Calculate the cost of using an appliance for a
certain amount of time.
To know
the cost of
using
electrical
appliances.
Write 3 questions you think need
answering to understand this electricity
bill.
What
How
Where
When
Why
To know the cost of using electrical
appliances.
•
The cost of an electrical
appliance depends on:
•
How much electrical
energy the device uses
•
Electricity tariff
(cost
per unit of electrical
energy).
Energy Transfer
(Joules)=
power
(Watts)
x time(sec
)
E
p
t
x
÷
To know the cost of using electrical
appliances.
Example-
•
A 100W lamp is left on for 10 minutes. How
much electrical energy is transferred?
•
Energy transferred (J)= power (W) x time (s)
To know the cost of using electrical
appliances.
Example-
•
A 100W lamp is left on for 10 minutes. How
much electrical energy is transferred?
•
Energy transferred (J)= power (W) x time (s)
–
100 x (10 x 60) minutes need to be converted to
seconds
–
100 x 600
–
60000J (1000J = 1kj)
–
60kj
To know the cost of using electrical
appliances.
1. If a 100W bulb is used for a time of 20 seconds; how much
energy does it use in this amount of time?
2. The bulb is left on for a period of 1 hour, how much energy
does it use?
3. A person needs 400W whilst riding a bike. How much
energy will they use in half an hour?
To know the cost of using electrical
appliances.
•
Energy companies use
units of electrical energy
called kilowatt-hours
(kWh) or simply units.
•
Units used = power x time
(kWh)
(W) (h)
The cost per unit depends on
the company, in the UK
between 10-15p.
To know the cost of using electrical
appliances.
Example-
•
You leave a 3kW heater on in your room. You
put it on at 8am and leave it on until 4pm.
•
If a unit (1kWh) costs 12.5p, how much would
it cost to leave it on?
Number of units used (kWh)= power (kW) x time (h)
Cost = number of units x cost per unit
To know the cost of using electrical
appliances.
Example-
•
You leave a 3kW heater on in your room. You put it on at 8am
and leave it on until 4pm.
•
Number of units = 3 x 8 (number of hours on)
= 24 units
•
If a unit (1kWh) costs 12.5p, how much would it cost to leave
it on?
Cost = 24 x 12.5
= 300p
= £3.00
Number of units used (kWh)= power (kW) x time (h)
Cost = number of units x cost per unit
To know the cost of using electrical
appliances.
•
An electric fire of power 3000W is used for 1 hour. How many
units of electricity has it used?
•
If each unit costs 9.4p how much has it cost to use it for this
time?
Number of units used (kWh)= power (kW) x time (h)
Cost = number of units x cost per unit
To know the cost of using electrical
appliances.
Success criteria-
State what factors affect
the cost of using
electrical appliances.
Calculate the energy
transferred by an
electrical appliance.
Calculate the cost of
using an appliance for a
certain amount of time.
•
WWW-
•
What went well-
•
EBI-
•
Even better if-
A microwave oven has a
power rating of 850W.
1. If the microwave oven is
turned on for 6 minutes,
how much energy will it
use?
Show clearly how you work
out your answer.
State the units in your
answer.
2. How many units of
electricity will it use?
3. If each unit costs 13.2p
how much would using it
this once cost?
To know the cost of using electrical
appliances.
Cost of devices
Questions:
1.
A light bulb is left on for an hour and has a power of 0.1 KW
how much did it cost?
2.
A
h
a
i
r
d
r
y
e
r
h
a
s
a
p
o
w
e
r
o
f
1
.
5
K
W
a
n
d
w
a
s
u
s
e
d
f
o
r
1
5
m
i
n
u
t
e
s
h
o
w
m
u
c
h
d
i
d
i
t
c
o
s
t
?
3.
A
3
0
0
0
W
f
i
r
e
i
s
l
e
f
t
o
n
t
o
w
a
r
m
a
r
o
o
m
f
o
r
2
0
m
i
n
u
t
e
s
.
H
o
w
m
u
c
h
d
i
d
i
t
c
o
s
t
?
4.
A light bulb is left on for 5 hours and has a power of 0.1KW
how much did it cost?
5.
A
h
a
i
r
d
r
y
e
r
h
a
s
a
p
o
w
e
r
o
f
1
0
0
0
W
a
n
d
w
a
s
u
s
e
d
f
o
r
h
a
l
f
a
n
h
o
u
r
,
h
o
w
m
u
c
h
d
i
d
i
t
c
o
s
t
?
6.
A
1
K
W
f
i
r
e
i
s
l
e
f
t
o
n
t
o
w
a
r
m
a
r
o
o
m
h
o
w
m
a
n
y
1
5
m
i
n
u
t
e
s
.
H
o
w
m
u
c
h
d
i
d
i
t
c
o
s
t
?
7.
A 3000 W oven is cooking your Sunday roast for 1 hour and
35 minutes. How much did it cost to cook it?
8.
A cd player has a power rating of 15 W. You listen to your
music for 20 minutes. How much did it cost?
9.
The 1.5 KW dishwasher, washes the dishes in 40 minutes.
How many KWh of electricity has it used? How much does it
cost per wash?
10.
T
h
e
s
c
h
o
o
l
h
a
s
a
s
e
t
o
f
3
0
l
a
p
t
o
p
s
i
n
r
o
o
m
5
7
.
T
h
e
y
a
r
e
u
s
e
d
f
o
r
8
h
o
u
r
s
e
v
e
r
y
d
a
y
,
e
a
c
h
o
n
e
h
a
s
a
p
o
w
e
r
r
a
t
i
n
g
o
f
3
0
W
.
H
o
w
m
u
c
h
d
o
e
s
i
t
c
o
s
t
t
o
r
u
n
t
h
e
m
i
n
a
s
c
h
o
o
l
w
e
e
k
?
Energy = Power x Time
Kilowatt-hours =kilowatts x hours
Take the cost of a unit of
electricity to be 14p
Learn how to calculate the cost of using electrical appliances in your home by considering factors like energy usage, electricity tariff, and energy transfer. Explore examples and questions to understand electricity bills and energy consumption better.
Uploaded on Sep 18, 2024 | 0 Views
Download Presentation
Please find below an Image/Link to download the presentation.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.If you encounter any issues during the download, it is possible that the publisher has removed the file from their server.
You are allowed to download the files provided on this website for personal or commercial use, subject to the condition that they are used lawfully. All files are the property of their respective owners.
The content on the website is provided AS IS for your information and personal use only. It may not be sold, licensed, or shared on other websites without obtaining consent from the author.
E N D
Presentation Transcript
To know the cost of using electrical appliances. List as many electrical appliances in your home as you can. How can we work out how much they cost?
To know the cost of using electrical appliances. Success criteria- State what factors affect the cost of using electrical appliances. Calculate the energy transferred by an electrical appliance. Calculate the cost of using an appliance for a certain amount of time. EFFECTIVE PARTICIPANTS
To know the cost of using electrical appliances. Write 3 questions you think need answering to understand this electricity bill. What How Where When Why
To know the cost of using electrical appliances. The cost of an electrical appliance depends on: How much electrical energy the device uses Electricity tariff (cost per unit of electrical energy). Energy Transfer (Joules)= power(Watts) x time(sec) E p x t
To know the cost of using electrical appliances. Example- A 100W lamp is left on for 10 minutes. How much electrical energy is transferred? Energy transferred (J)= power (W) x time (s)
To know the cost of using electrical appliances. Example- A 100W lamp is left on for 10 minutes. How much electrical energy is transferred? Energy transferred (J)= power (W) x time (s) 100 x (10 x 60) minutes need to be converted to seconds 100 x 600 60000J (1000J = 1kj) 60kj
To know the cost of using electrical appliances. 1. If a 100W bulb is used for a time of 20 seconds; how much energy does it use in this amount of time? 2. The bulb is left on for a period of 1 hour, how much energy does it use? 3. A person needs 400W whilst riding a bike. How much energy will they use in half an hour?
To know the cost of using electrical appliances. Energy companies use units of electrical energy called kilowatt-hours (kWh) or simply units. Units used = power x time (kWh) (W) (h) The cost per unit depends on the company, in the UK between 10-15p.
To know the cost of using electrical appliances. Number of units used (kWh)= power (kW) x time (h) Cost = number of units x cost per unit Example- You leave a 3kW heater on in your room. You put it on at 8am and leave it on until 4pm. If a unit (1kWh) costs 12.5p, how much would it cost to leave it on?
To know the cost of using electrical appliances. Number of units used (kWh)= power (kW) x time (h) Cost = number of units x cost per unit Example- You leave a 3kW heater on in your room. You put it on at 8am and leave it on until 4pm. Number of units = 3 x 8 (number of hours on) = 24 units If a unit (1kWh) costs 12.5p, how much would it cost to leave it on? Cost = 24 x 12.5 = 300p = 3.00
To know the cost of using electrical appliances. Number of units used (kWh)= power (kW) x time (h) Cost = number of units x cost per unit An electric fire of power 3000W is used for 1 hour. How many units of electricity has it used? If each unit costs 9.4p how much has it cost to use it for this time?
To know the cost of using electrical appliances. WWW- What went well- Success criteria- State what factors affect the cost of using electrical appliances. Calculate the energy transferred by an electrical appliance. Calculate the cost of using an appliance for a certain amount of time. EFFECTIVE PARTICIPANTS EBI- Even better if-
To know the cost of using electrical appliances. A microwave oven has a power rating of 850W. 2. How many units of electricity will it use? 1. If the microwave oven is turned on for 6 minutes, how much energy will it use? 3. If each unit costs 13.2p how much would using it this once cost? Show clearly how you work out your answer. State the units in your answer.
Questions: Cost of devices 1. A light bulb is left on for an hour and has a power of 0.1 KW how much did it cost? Device Power (KW) Time (hours) Energy (KWh) Cost (p) 2. A hairdryer has a power of 1.5 KW and was used for 15 minutes how much did it cost? 3. A 3000W fire is left on to warm a room for 20 minutes. How much did it cost? iron 2 0.5 oven 3 1 hour 4. A light bulb is left on for 5 hours and has a power of 0.1KW how much did it cost? bulb 0.04 5 hours 5. A hairdryer has a power of 1000W and was used for half an hour, how much did it cost? Device Power (Watts) Time Energy (KWh) Cost (p) 6. A 1 KW fire is left on to warm a room how many 15 minutes. How much did it cost? 7. A 3000 W oven is cooking your Sunday roast for 1 hour and 35 minutes. How much did it cost to cook it? iron 2000 10 mins oven 3000 2 hours 8. A cd player has a power rating of 15 W. You listen to your music for 20 minutes. How much did it cost? bulb 40 3.5 hours 9. The 1.5 KW dishwasher, washes the dishes in 40 minutes. How many KWh of electricity has it used? How much does it cost per wash? Energy = Power x Time 10. The school has a set of 30 laptops in room 57. They are used for 8 hours every day, each one has a power rating of 30 W. How much does it cost to run them in a school week? Kilowatt-hours =kilowatts x hours Take the cost of a unit of electricity to be 14p
