Electricity

Question 1

Current

Answer 1

An electric current is the rate of flow of charge through a conductor.

Question 2

Voltage

Answer 2

Voltage is a measure of the amount of energy which the charge is carrying.

Question 3

Q

Answer 3

Charge (C)

Question 4

E

Answer 4

Energy

Question 5

V

Answer 5

Voltage

Question 6

I –

Answer 6

Current (A)

Question 7

T

Answer 7

Time (s)

Question 8

E

Answer 8

Energy (J)

Question 9

V

Answer 9

Voltage (V)

Question 10

R

Answer 10

Resistance (Ω)

Question 11

P

Answer 11

Power (W)

Question 12

learn symbols of electric circuits

Answer 12

took a screenshot

Question 13

What happens when you disconnect one of the Lamps in series and paralllel?

Answer 13

In series circuits when one bulb is broken or does not work anymore it mean the whole circuit will not work anymore because there is no more current going through
In parallel all the other lamps still work because the current only stopped going through the lamp you unscrewed, the other lamps in the circuit are still working because the current in still going through those lamps(loops)

Question 14

What happens to the brightness of the lamps as more are added in parallel?

Answer 14

as more lamps are added the brightness of the lamps stay the same

Question 15

advantages and disadvantages of series

Answer 15

Require fewer wires to construct(cheaper)
If a fault occurs the whole circuit stops working

Question 16

advantages and disadvantages of parallel

Answer 16

Each loop can be controlled separately
If one loop breaks the others keep working
Circuits are more complicated to construct

Question 17

resistor

Answer 17

Current is directly proportional to Voltage
Resistance is constant as power supply varies

Question 18

filament lamp

Answer 18

The current/voltage graph is a curve
Resistance increases as the voltage increases and the lamp gets brighter and hotter. Atoms and ions in metal vibrate more and make it harder for the electrons to flow through

Question 19

LED (diode)

Answer 19

Current/Voltage graph is a curve
Resistance decreases as the voltage increases
It only allows current to flow in one direction

Question 20

How would you plot a voltage/current for a filament lamp?

Answer 20

• The quantities to be measured were current and voltage
• The apparatus used were voltmeter, ammeter, filament lamp, power supply and wires.
• The voltmeter was measured in parallel to the filament lamp while the the ammeter, filament lamp and power supply were in series
• In this experiment we don’t need to do repeats because they are not generally useful for the results.
• To insure accuracy make sure the readings are stable and try to pick the value in the middle if the reading are varying. Make sure there are no loose wires and all are fimly put in.
• There are no equation in this experiment
• To ensure safety ensure that the power supply does not surpass 12Volts, always have a low voltage power supply.

Question 21

Light Dependent Resistor
(LDR)

Answer 21

-The resistance changes with light.
-As the light gets brighter the resistance of the LDR decreases.

Question 22

Thermistor

Answer 22

-Resistance changes with temperature.
-As the temperature increases the resistance of the Thermistor decreases..

Question 23

How to pick fuse?

Answer 23

When picking a fuse for a device we should always pick the SMALLEST one which will NOT melt.

Question 24

Fuse

Answer 24

it is a small wire that will break and not allow current to flow if current gets too high and might damage the human

Question 25

Earth wire

Answer 25

When a fault occures the hearting element of the kettle touches the metal case. The kettle is now life and can electrocute a person if they don’t have a earth wire.

If you do have a earth wire you will not be electrocuted. The current always chooses path with least resistance. So to the route to the ground the current will prefer to take the route through the earth wire rather then the person(keeping the safe). If this happens the fuse blows

Question 26

2 main dangers of electricity

Answer 26

-someone can be electrocuted
-cause overheating, you can be burned or something can catch fire

Question 27

Insulator

Answer 27

insulator are used as a way to protect you from touching objects that may become live.
Double insulator is when the appliance are insulated in plastic

Question 28

Direct Current – d.c.

Answer 28

A d.c. supply (such as a battery or cell) produces a flow of charge through a circuit in one direction only

Question 29

Alternating Current – a.c.

Answer 29

An a.c. supply (such as the Mains) produces a flow of charge that regularly reverses its direction through a circuit

Question 30

How does a ballon stick to the wall?

Answer 30

The balloon is negatively charged whilst the wall is positively charged (it has the same number of positive and negative charges). The negatively charged balloon repuls the negative charges in the wall away. The front face of the wall now has a net positive charge. This attracts the negative balloon.

Question 31

How does a paper stick to a comb?

Answer 31

The scraps of paper are electrically neutral. The positively charged comb attracts the negative charges in the paper. The side of the paper nearest the comb now has a net negative charge. The positive and negative charges attract and the paper sticks to the comb.