Electricity and Circuits

Question 1

what are delocalised electrons

Answer 1

free to move negatively charged electrons

Question 2

what is the symbol that represents charge

Answer 2

Q

Question 3

unit for charge?

Answer 3

Coulombs

Question 4

how do you represent a Coulomb of charge (letter)

Answer 4

C

Question 5

what does it mean if there is 1 Coulomb of charge per second

Answer 5

there is 1 Amp

Question 6

what does one mean by a Coulomb in general

Answer 6

millions and millions of electrons

Question 7

current- defenition

Answer 7

the rate of flow of charge

Question 8

what is the unit for current (+ letter)

Answer 8

Amps (A)

Question 9

what is current represented by (the letter)

Answer 9

I

Question 10

how does one measure current

Answer 10

ammeter

Question 11

how is an ammeter connected in a circuit

Answer 11

in series

Question 12

what is potential difference

Answer 12

the amount of energy transferred per Coulomb of charge

Question 13

what is the symbol: potential difference

Answer 13

V

Question 14

potential difference- unit

Answer 14

Volts (V)

Question 15

what is 1V equal to

Answer 15

1V = 1J/C

1 Volt = 1 Joule/ Coulomb of charge

Question 16

how does one measure voltage

Answer 16

voltmeter

Question 17

how is a voltmeter connected to a circuit

Answer 17

in parallel

Question 18

why is a voltmeter connected in parallel (2)

Answer 18

1) it needs to measure across not through

2) it has a high resistance and would consume the current and not be able to measure the PD effectively

Question 19

describe how to draw an open light switch symbol (4)

Answer 19

• leave gap
• colour circle
• draw a line leading upwards
• unconnected, colour other circle

Question 20

describe how to draw a closed light switch symbol (4)

Answer 20

• leave gap
• colour circle
• colour other circle
• draw line leading from the bottom of circle 1 to the top of circle 2 so that it is connected

Question 21

describe how to draw a light bulb (3)

Answer 21

• leave a gap
• draw a circle
• draw a cross through it

Question 22

describe how to draw a battery (6)

Answer 22

• draw long line for positive
• short line for negative
• dash connecting short and long lines
• draw second positive
• draw second negative
• draw second dash connected to the wire

Question 23

describe how to draw a cell (3)

Answer 23

• draw long line for positive
• draw short line for negative
• connect it to the wire using two dashes from the outer side of each line

Question 24

describe how to draw an ammeter

Answer 24

• leave a gap
• draw a circle
• write a capital A inside

Question 25

describe how to draw a voltmeter

Answer 25

- find a component - draw a line coming out on its left - draw half a line towards the direction at a 90 degree angle facing from it - draw a circle - draw another half line mirroring the first - connect the second half line to the wire - write a capital V in the circle

Question 26

what happens if 2 positives or 2 negatives in a battery are next to one-another

Answer 26

current will not flow

Question 27

'in series' definition

Answer 27

current has and flows along one path only

Question 28

'in parallel' definition

Answer 28

current splits off into two or more branches before recombining

Question 29

describe current in a series circuit

Answer 29

the same at every point

Question 30

describe current in a parallel circuit

Answer 30

splits/ joins up at junctions (nodes)

Question 31

what are nodes?

Answer 31

junctions where current meets or splits up in a parallel circuit

Question 32

what is a conductor

Answer 32

allows heat and/ OR electricity to pass through easily

Question 33

what is an insulator

Answer 33

heat or electricity cannot pass through it easily

Question 34

example of an electrical conductor

Answer 34

copper (wires)

Question 35

example of an electrical insulator

Answer 35

paint

Question 36

what is resistance?

Answer 36

the opposition of current

Question 37

what happens when resistance occurs

Answer 37

delocalised electrons collide with positive metal ions in conductors

Question 38

what happens to current in the presence of a high resistance

Answer 38

high resistance = low current

Question 39

symbol for resistance

Answer 39

R

Question 40

unit for resistance

Answer 40

Ohms

Question 41

what do we represent Ohms by

Answer 41

Ω

Question 42

describe 3 subsequent effects of high resistance

Answer 42

1) high resistance ----- 2) high potential difference ----- 3) more collisions ---- 4) more energy transferred per Coulomb of charge

Question 43

describe 2 subsequent effects of a long wire

Answer 43

1) long wire ---- 2) more collisions ---- 3) higher resistance ----

Question 44

equation for working out charge

Answer 44

Q = I x T

Question 45

equation for working out electricty

Answer 45

E = Q x V

Question 46

equation for potential difference

Answer 46

V = I x R