Electricity(p)

Question 1

What are the components required in a basic circuit?

Answer 1

Battery, cells, filament lamp, switch and wire

Question 2

What is the current?

Answer 2

the measure of electrons around a circuit recorded in amps

Question 3

What is potential difference?

Answer 3

force driving flow of electrons recorded in voltage

Question 4

What is the resistance?

Answer 4

Everything that resists/opposed flow of electrons

Question 5

What is the “conventional current” suggest about the flow of electrons?

Answer 5

Current flows through positive to negative

Question 6

What will happen when there is an increase in temperature for the wires?

Answer 6

There will be an increase in resistance due to the metal vibrating faster, making it harder for electrons to pass through wire

Question 7

What do diodes do?

Answer 7

Only allow current to flow one way around a circuit

Question 8

What is the equation which included voltage, current and resistance?

Answer 8

V=IR
Voltage =current x resistance
(This increases proportionally)

Question 9

what are the Components in a circuit?

Answer 9

-cell
-battery
-open switch
-closed switch
-filament lamp
-fuses
-diode
-light emitting diode
-fixed resistor
-variable resistor
-light dependant resistor
-thermistor

Question 10

What are light dependent resistors?

Answer 10

When there is a high resistance when it’s dark

Question 11

What are thermistor?

Answer 11

High resistance means more cold

Question 12

What is the formula involving voltage, energy, current and time?

Answer 12

Energy = voltage x current x time

Question 13

How is energy prepared to be sent access national grids?( stgs)

Answer 13

1. Nuclear power station generates thermal energy. Which is used to turn water into steam.
2. Steam then rises and turns turbines. Which provides kinetic energy
3. The kinetic energy is converted to electrical energy m. That’s sent actos national grid

Question 14

What does the national grid do?

Answer 14

Transmits huge amounts of power to towns

Question 15

Explain the process of the national Grid?

Answer 15

•energy goes through step up transformer, which increases voltage and decreases current( to minimise power loss)

• then transmitted between pylons.

• step down transformers reduce voltage for towns and increase current

Question 16

What happens if the current or voltage is too high?

Answer 16

Is dangerous for voltage

If current to high. Then the energy is wasted by heat when transmitting current

Question 17

When does electricity demand peek?

Answer 17

In afternoon

Question 18

How many volts and hertz does a main supply have?

Answer 18

-230 volts
-50hz

Question 19

What 3 wires are in a plug?

Answer 19

Live wire
Earth wire
Neutral wire

Question 20

What is the live wire?

Answer 20

-brown
-carries potential difference
-carries 230v
-carries electricity into plug

Question 21

What is neutral plug?

Answer 21

-blue
-completes circuits by carrying away current
-carries 0v
-carries electricity out of plug

Question 22

What is earth wire?

Answer 22

-doesn’t normally carry current
-yellow and green
-carries 0v
-stops appliance casing becoming live
-provides alternating path to flow to prevent electric shock

Question 23

What are wires made from?

Answer 23

Copper and coated in layers of insulating plastic

Question 24

What are the risks of electrical appliances?

Answer 24

• surges(when person turns appliance on an off. Fault in circuit/ appliance)
• damaged appliance
• fires
• electric shock

Question 25

What are the method of precaution for surges?

Answer 25

Fuses

Circuit breakers

Earthing

Double insulate

Question 26

What are fuses (in appliance)

Answer 26

Breaks circuit when current is too high. Is very thin piece of wire. When heated melts and breaks circuit. {So no current can flow in}

-fuse rating always a bit above appliance

-simple and cheap

-permanently broken after single usage

Question 27

What are circuit breakers?

Answer 27

-breaks circuit whenever there’s a surge

-by tripping the circuit breaker. To turn of circuit so it’s reset.
-more expensive than fuse

Question 28

What is earthing (using earth wire)?

Answer 28

When Earth wire provides alternative pathway. Where electricity is diverted through the earth wire.
As the earth wire is also connected to the appliance

Question 29

What is double insulate?

Answer 29

-doesn’t conduct electricity
-can’t get electric shock
-only has live and neutral wire
-covered in plastic casing
-exposes no metal parts