Electric

Question 1

Electricity

Answer 1

Electricity is generated by electrons moving from atom to atom

(screenshot of symbols)

Question 2

CONDUCTOR:

Answer 2

• Materials such as metals
• Free electrons produces a flow of
electric charge / electricity
• E.g. Copper wires

Question 3

INSULATOR:

Answer 3

• Materials with few free electrons / 
restricts the flow of electrons
• Keeps us safe
• E.g. Rubber & Plastics, PVC, Porcelain 
& glass

Question 4

CURRENT:

Answer 4

• The electrical charge moving/flowing through a a conductor = electrical current
• A current flows from negative to positive

Question 5

Direct Current | DC

Answer 5

• Current flows in one direction from
negative to positive
• e.g. laptpops, batteries, cellphones,
solar power

Question 6

Alternating Current | AC

Answer 6

• Current flows back and forth in a circuit
between positive & negative
• What we use in our home
• Powers bigger appliances
• Far more efficient that DC

Question 7

CIRCUIT:

Answer 7

• The route/path that electrons travel

* A circuit can be connected in series or parallel

Question 8

Cyrcit in Series

Answer 8

• Flows in a line through each component to the next

•

Question 9

Cyrcit in Parallel

Answer 9

• What we use in the building industry

* Flows to and from each resistor individually

Question 10

RESISTANCE:

Answer 10

• Restricts the flow of electrons within a circuit
• E.g. Adding a Light Bulb to a circuit is form of a resistor.
• Electricity has to pass through the bulb in order to continue its flow
• Copper is used because if it’s low resistance rate
• When resistance increases, current decreases
• Resistance generates heat

Question 11

APMPERE / AMPS (A):

Answer 11

• Measures the volume of an electrical current
• i.e. measures the amount of electrons flowing through a wire per second.
• E.g. the amount of water that flows through a pipe.
• The higher the amperage required by a device, the more current it will use

Question 12

VOLTS (V):

Answer 12

• Unit of pressure/intensity of an electrical current
• The higher the voltage the more electrical current will flow
• In SA, the single phase voltage for domestic use = 220V
• Transformers is used to adjust voltage up or down if necessary e.g.
in lights

Question 13

WATT (W):

Answer 13

• Unit of power
• Shows the current drain of consumption of an appliance
• Unit is used to charge users for the use of electrical energy
• 1000 watts = 1 KW

Question 14

The most economical way to distribute electricity

Answer 14

is at high voltages with low currents.
High currents = high temperatures = melted wires
Low voltage = not enough pressure = no electricity

Question 15

Electrical Supply to domestic homes

Answer 15

is connected to a meter that measures the usage in watts used per
hour (W/h – kW/h)

Question 16

From the meter multi-core PVC insulated armoured cabling connects the meter box to the building, as
well as other loose standing outbuildings on the property

Answer 16

• 500mm deep in the ground

* Connects to a Distribution board

Question 17

Distribution Board (DB) usually contains the following 
circuits:

Answer 17

• Plugs 
• Lights
• Geyser, Stove/Oven, Under-floor heating, Security 
Lights, Large Airconditioners
• Pool & Gate motors 
• Sub-distribution board

Question 18

Position Regulations of DB:

Answer 18

• May not be mounted in bathrooms
• May not be mounted above cooking appliances
• May not be mounted within one meter of a tap
• At least 1.2m above finished floor level (AFFL)
• The main switch may not be higher than 2.2m above
finished floor level (AFFL)
• 800mm of open/clear space to be provided in front
of DB’s

Question 19

Plug Points:

Answer 19

• Single, Double or combination outlet
• Fitted to 100x50 or 100x100 built-in metal or PVC wall-box
• Plug sockets are designed for 15A current flow

Question 20

Light Switches:

Answer 20

• Light switch sockets are fitted into a 100x50 or 100x100 built-in metal or PVC wall-box
• Accommodates 1 to 8 switches
• Designed for 10A current flow
• Switches can also include dimmer switches
• Dimmer switches controls the power flow (W) to lamps