Flashcards in Chapter 8 Deck (38)

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1

## What is the SI units for electric current

### Amperes(A)

2

## What is electric current defined as?

### Electric current is defined as the rate of flow of charge

3

##
What is the equation linking

-Current

-Charge

-Time

###
Q = I x t

4

## What is the SI unit for charge

### Coulombs

5

## What is current derived from the equation Q = It

### The amount of charge passing a given point in circuit per unit time

6

## What is 1A equal to

### 1 C/s

7

## What type of property is electric charge

### A physical property

8

## What are the 2 types of charges

###
1)Positive

2)Negative

9

## What are ions described as when they referred by their charges

### Relative charges

10

## What is e

### Elementary Charge

11

## What is Elementary Charge

###
The relative charge a proton has e

(A electron has a charge of

-e)

12

## What is the value of e

### 1.60 x 10^-19C

13

## What is net charge

### the charge on the object which is due to its gain or loss of electrons

14

## How do you calculate the net charge on a object

###
Q = ne

Q-Coulombs

n-Number of electrons

e-Elementary charge

15

## What is a charge carrier

### carriers of charge(lol)

16

## Name 2 charge carriers and where they operate

###
Electrons - Metals

Ions - Liquids

17

## What is one way to make electrons to move in a metal wire

### to make a positive end- this means all the electrons will flow towards to this direction

18

## The greater the the rate of charge flow

### the greater the electric current in a wire

19

## What may a large current be due to?

###
1)A greater number of electrons moving past a given point each second

(e.g. a wire with a greater cross-sectional area)

2)A increase in the speed of the electrons moving faster through the metal

20

## What is Conventional current

### The direction of the electric current from the positive terminal to negative terminal

21

## What is electron flow

### The direction of the electric current from the negative terminal to the positive terminal

22

## What is the name of the liquids that can carry current

### Electrolyte

23

## What are all the electrolyte

###
Molten ionic compounds

or

Ionic solution

24

## What is the positive and negative electrodes called

###
1)Cathode(-)

2)Anode(+)

25

## What is an ammeter used for

### To measure the electric current at any point in a circuit

26

## How much resistance does an ammeter have

###
Very little resistance

so it does not affect the current

27

## Is the ammeter in parallel or in series

### series

28

## What does the conservation of charge state

### That electric charge cannot be created nor destroyed

29

## What does Kirchhoff's first law states

### For any point in an electrical circuit, the sum of currents into that points is equal to the sum of currents out of the circuit

30

## What is number density

### It is the number of free electrons per cubic metre of material.

31

## What does a higher number density mean

### The greater the number density the better the electrical current

32

## What are the 3 types of number density classification

###
1)Insulators

2)Semi-conductors

3)Conductors

33

## What is the value of number density for conductors

### Y x 10^28m-3

34

## What is the value of number density for semi-conductors

### Y x 10^17m-3

35

## Why does appliances turn on instantly

### This due to all the free electrons in the wire moving almost instantly

36

##
What is the equation linking

-Current

-Mean drift velocity

-Elementary Charge

-Number of electrons

-Cross sectional area

### I = A x n x e x v

37

## What is mean drift velocity

### The average velocity gained by the free electrons of a conductor, with which the electrons get drifted under the influence of an electric field

38