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Flashcards in electricity Deck (54)
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1

what is electric current?

Electric current is the flow of electrical charge

2

what is current measured in?

amps

3

what is electrical charge measured in?

coulombs

4

electrical charge equation:

charge flow = current x time

5

what is the resistance of a component?

Resistance of a component is the measure of how it resists the flow of charge

6

the higher the resistance:

- the more difficult for charge to flow
- the lower the current

7

what is resistance measured in?

ohms

8

what does potential difference tell us?

potential difference tells us the difference in electrical potential from one point at a circuit to another

9

the bigger potential difference across a component:

-the greater flow of charge through
-the bigger the current

10

what is potential difference measured in?

volts

11

potential difference equation

potential difference= current x resistance

12

what does a current graph show?

a current graph shows the relationship between potential difference and current for any component

13

resistor graph:

straight line graph
(resistance remains constant)

14

filament lamp graph:

indicated by a curved graph
(resistance increase as current increases)

15

diodes graph:

horizontal line along x axis
(no current flows)

16

what happens to the resistance of a thermistor?

The resistance of a thermistor the decreases as the temperature increases

17

what happens to the resistance of an LDR?

The resistance of an LDR decreases as light intensity increases

18

what happens in a SERIES circuit?

in a series circuit:
current: STAYS the same
potential difference: SHARED

19

what happens in a PARALLEL circuit?

in a parallel circuit:
current: SHARED
potential difference: NOT shared

20

what happens if a component in a SERIES circuit breaks or is removed??

the rest of the components WILL NOT work

21

what happens if a component in a PARALLEL circuit breaks or is removed??

the rest of a component WILL continue to work

22

what does the power of a device depend on?

The power of a device depends on the potential difference across it and the current flowing through it.

23

a device with higher potential difference will....

use more energy per second
(more powerful)

24

2 equations for POWER

power= potential difference x current

power=(current)2 x resistance

25

DIRECT current potential difference:

DIRECT
-one is always positive or always negative
-> makes current constant

26

when is DIRECT current used?

direct current is supplied by cells and batteries

27

ALTERNATING current potential difference:

ALTERNATING
-alternates from positive to negative
-> makes current direction alternate

28

when is ALTERNATING used?

alternating current is used in mains electricity

29

what colour is live wire?

love wire is brown

30

what colour is neutral wire?

neutral wire is blue