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