physics -mains electricity cp11 p2

Question 1

mains electricity basic facts

Answer 1

• works at 230V and uses
  A.C.( Alternating current)
• frequency of 50Hz
  -Anything with a 3 pin plug
  uses mains electricity

Question 2

live wire
colour
voltage
job

Answer 2

Brown
- 230V so is the dangerous wire.
-It carries the
current to the appliances. -The fuse is connected to
the live wire and current flows through

Question 3

neutral
colour
voltage
job

Answer 3

Blue
- 0V
-this wire lets the current
flow back out of
the appliance

Question 4

earth wire
colour
voltage
job

Answer 4

-Green and yellow stripes -0V.
-This wire is connected to
the outer metal case to
stop you getting an
electric shock

Question 5

cable grip

Answer 5

Holds the main cable tightly into the plug.

Question 6

how electricity usually flows

Answer 6

-Current flows through the
fuse in the live wire, into the kettle and back out through the neutral wire.
-The Earth wire does
nothing, it is connected to the case, just in case there is a fault

Question 7

if a fault occurs ..

Answer 7

-The current flows through the fuse in the live wire, through the metal case and returns in the earth wire.
-Since the case has a
lower resistance the size of the current increases and the fuse BLOWS, so no current can flow.

Question 8

RCCB—Residual current circuit breaker

Answer 8

-This switches off a circuit
if it detects more current
in the live wore than the neutral wire.
- They are quicker than
fuses.
-ADV - flick to switch back
on and safer than fuses
-DIS - More expensive

Question 9

what is double earthing

Answer 9

-If an appliance has a
plastic case and an earth
wire
-chances of getting a shock are less.

Question 10

electrical dangers

Answer 10

-The live wire of switches
and sockets is at 230V.
-If you touch these when wet, the electricity can flow
through you and give you a shock.
-No plugs in bathrooms!