electricity (paper 1)

Question 1

define electricity

Answer 1

flow of charge

Question 2

LED definition

Answer 2

diode which emits light when a small current passes through

Question 3

fuse defnition

Answer 3

melts if current circuit is too large

Question 4

bulb definition

Answer 4

when given electricity it lights up

Question 5

LDR definition

Answer 5

• resistant which values changes through light
• can be used for automated lights

Question 6

thermistor definition

Answer 6

resistor which values changes through heat

Question 7

diode definition

Answer 7

only allows current to flow in one way

Question 8

ammeter

Answer 8

resistor where its value can be changed

Question 9

voltmeter definition

Answer 9

measures voltage

Question 10

fixed resistor definition

Answer 10

causes resistance in circuit

Question 11

cell definition

Answer 11

gives energy to circuit

Question 12

battery definition

Answer 12

gives energy to circuit

Question 13

variable resistor

Answer 13

resistor where its value can be changed

Question 14

what is current

Answer 14

rate of flow of charge

Question 15

what does an ammeter measure in?

Answer 15

current (A)

Question 16

what does a voltmeter measure in?

Answer 16

potential difference (V)

Question 17

list the 4 things resistance of a wire depends on

Answer 17

material
thickness
length
temperature

Question 18

define proportional

Answer 18

if you double the voltage then the current doubles

Question 19

explain how rubbing an acetate rob with a cloth causes the rod and cloth to become charged (4)

Answer 19

• Friction causes electrons to move from the rod and on to the cloth.
• The charge on the rod is positive, as it has lost electrons.
• The charge on the cloth is negative, as it has gained electrons.
• the movement of electrons is the reason for the rod and cloth becoming charged.

Question 20

define electric current

Answer 20

flow of electric charge

Question 21

define potential difference

Answer 21

driving force that pushes the charge around

Question 22

colours of earth wire

Answer 22

green + yellow

Question 23

colour of live wire

Answer 23

red

Question 24

colour of neutral wire

Answer 24

blue

Question 25

gradient = ?

Answer 25

change in y/change in x

Question 26

average walking speed

Answer 26

1.5m/s

Question 27

average running speed

Answer 27

3.0m/s

Question 28

average cycling speed

Answer 28

6.0m/s

Question 29

describe the resistance of a diode when connected in a circuit in the forward direction

Answer 29

low resistance

Question 30

explain one advantage of using LEDS rather than a filament lamp

Answer 30

low heat emission output making them safer + more environmentally friendly

Question 31

define alternating current

Answer 31

electric current that reverses its direction of flow many times