L
L2. Plugs
LO: TU the features of a plug
Write the date,
title and LO in
your book
Knowledge Retrieval
Starter
3. How does the p.d change in an AC circuit?
1. What does ac and dc stand for?
4. Write 4 devices that use Alternating Current
2. What’s the frequency and voltage of the U.K
mains?
L
L2. Plugs
Purple pen
your work
LO: TU the features of a plug
Knowledge Retrieval
Starter - ANSWERS
3. How does the p.d change in an AC circuit?
Zero – positive peak voltage – zero – negative
peak voltage – zero - ….
1. What does ac and dc stand for?
AC: Alternating current
DC: Direct current
4. Write 4 devices that use Alternating Current
1. Washing machine
2. Vacuum cleaner
3. Oven
4. Fridge
5. Boiler
6. Heater (electrical)
2. What’s the frequency and voltage of the U.K
mains?
Frequency = 50 Hz
Voltage = 230V
Topic P2b – Domestic Electricity - Overview
L1: a.c and d.c.
L4: Electrical energy
transfers
L7: Revision of
‘Domestic Electricity’
L2:The parts of a plug
L5: Electrical Work
and Fuses
L8: End of topic test
L3: Electrical Power
L6: The National Grid
Lesson Objectives
Write the
definitions
in your
glossary
• TK the function of each wire
• TU the function of a fuse
• TBAT explain why double insulation is used instead of
the Earth wire
Keywords: Live, neutral, earth
E
Plugs
We have all seen a plug before,
but does anyone know why we
have three prongs?
This is what the inside of a
plug looks like.
The casing of the wire is
made out of plastic
because plastic is a
poor conductor of
electricity.
E
Function of the wires
Neutral
Completes
the circuit
Live
Carries
the
current
E
Function of the wires
Earth: safety wire
Stops a fault
making the
appliance live
E
The brown wire (live) carries the
potential difference from the mains.
It is also connected to the fuse.
The blue wire (neutral)
completes the circuit for the
appliance.
The green and yellow wire
(Earth) is the safety wire that
stops appliances becoming live.
E
Where does each wire go?
 blue goes left
brown goes
right
striped goes to
the top
Copy this in
your book
A
Quick check – Where does each wire go?
Earth
Neutral
Live
2
minutes
E
Electrical Safety
Fuses
Earth
wire
Double
insulation
E
Fuse
A fuse is a device that is used
to protect appliances from a
current which is too high
• Connected to the live wire
• We need to replace them
after they get damaged
E
The live wire is connected to a fuse which
will break if the current is too high.
10A 
20A 
13A
13A
10A 
E
Earth wire
 When an appliance is
working
correctly,
no
electricity flows through the
earth wire
 If the live wire becomes
loose and touches the metal
case, a very large current
flows to earth and breaks the
fuse, breaking the circuit
E
Double Insulation
A
Activity
5
minutes
Extension: Explain why the outer insulation is made
out of plastic.
____________________________________________
____________________________________________
____________________________________________
______________________________
R
Review
Collect the worksheet
R
Specifications
N
Topic P2b – Domestic Electricity - Overview
L1: a.c and d.c.
L2:The parts of a plug
L3: Electrical Power
NEXT
L4: Electrical energy
transfers
L7: Revision of
‘Domestic Electricity’
L5: Electrical Work
and Fuses
L8: End of topic test
L6: The National Grid