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Flashcards in Physics 6 Deck (85)
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What is static electricity ?

Electricity that is not free to move

1

What happens when two insulating materials are rubbed together ?

Electrons will be rubbed off one, on to the other

2

True or False - only electrons move

True - negative charges are formed when electrons move to the material. Positive charges are caused by electrons moving elsewhere

3

What is current ?

The flow of electric charge round a circuit

4

What is potential difference ?

The 'driving force' that pushes current round

5

What is resistance ?

Anything which slows the flow down in the circuit

6

The greater the resistance over a component, the .....

Smaller the current that will flow

7

What is current measured in ?

Amperes

8

How do you work out the current in a circuit ?

Charge divided by time

9

What is potential difference measured in and how do you find it ?

Volts, it is the amount of energy transferred (work done) per unit of charge. So...

Work done divided by charge

10

How do you measure the current flowing through the component ?

Using an ammeter. It can be placed anywhere in series

11

How do you measure the potential difference across a component ?

Using a voltmeter. It must be placed in parallel around a component

12

What is a standard test circuit ?

One of the simplest circuits you can make. It is use to test components and find V-I graphs

13

What does a variable resistor do ?

Alters the current flowing through a circuit

14

Why does a V-I graph of a filament bulb curve ?

As the temperature of the filament increases the resistance increases

15

Why does resistance increase with temperature ?

When an electrical charge flows through a resistor some of it is converted into heat energy. The ions vibrate more because they are heated, making it harder for charge- carrying electrons to get through

16

What does Current x Resistance =

Potential difference

17

What does a diode do ? How does it do this ?

It regulates potential difference in a circuit by only letting current through in one direction

18

What does a light emitting diode do ?

Emits light when a current flows through in a certain direction

19

What does an LDR do ?

It changes it's resistance depending on the intensity of light. In bright light the resistance falls and in darkness the resistance is high

20

What does a thermistor do ?

It's resistance depends on the temperature. In hot condition the resistance is low and vice versa

21

What is a series circuit ?

When all the components are connected in a line. If one component is disconnected the circuit breaks.

22

What is shared an what is the same in a series circuit ?

Potential difference is shared and current is the same

23

How is potential difference shared ?

If a component has more resistance it has a bigger share I the potential difference

24

What is a parallel circuit ?

When each component is separate. If one component is disconnected it will continue to work.

25

In a parallel circuit what is shared and what is the same ?

Potential difference is the same and current is shared

26

What is the UK mains supply ?

230 volts

27

What I the frequency of the AC mains supply ?

50Hz

28

What is the difference between mains supply (AC) and battery supply (DC) ?

Alternating current goes back and forward but direct current travels in the same direction

29

How do you work out the frequency of an electricity supply ?

1 divided by time period