circuits, voltage, current and resistance

Question 1

what does an ammeter do?

Answer 1

measures current

Question 2

what does a voltmeter do?

Answer 2

measures the voltage

Question 3

what does a switch do?

Answer 3

breaks the circuit

Question 4

what does a resistor do?

Answer 4

used to limit the current that flows

Question 5

what does a diode do?

Answer 5

allows current to flow

Question 6

what does a lamp do?

Answer 6

changes electrical energy to light energy

Question 7

what does a cell do?

Answer 7

provides the push of an electrical supply

Question 8

what is current?

Answer 8

rate of flow of electrons in a circuit

Question 9

what is current measured in?

Answer 9

amps (A)

Question 10

how is an ammeter connected?

Answer 10

in series

Question 11

what is voltage?

Answer 11

push force in a circuit

Question 12

what is voltage measured in?

Answer 12

volts (V)

Question 13

how is a voltmeter connected?

Answer 13

in parallel with component

Question 14

what is a series circuit?

Answer 14

different components follow one after the other

one path for current to flow

Question 15

what is the current like in a series circuit?

Answer 15

the same

Question 16

what happens when you unscrew a bulb?

Answer 16

circuit breaks

Question 17

what happens in series circuits when you add bulbs?

Answer 17

decreases current and brightness of each bulb

Question 18

what is a parallel circuit?

Answer 18

components are side by side

more than one path for current to flow

Question 19

what is the current like in a parallel circuit?

Answer 19

some goes through one lamp and some goes through others

it splits and joins at junctions

Question 20

what are the advantages of a parallel circuit?

Answer 20

independent operation of bulbs

Question 21

what do all the bulbs have?

Answer 21

the same brightness

Question 22

what is resistance?

Answer 22

the greater the resistance the less current flows

less resistance, more current

Question 23

how does length affect resistance?

Answer 23

more atoms, more collisions per second, larger resistance

Question 24

how does temperature affect resistance?

Answer 24

atoms vibrate more, more collisions, larger resistance

Question 25

how does thickness affect resistance?

Answer 25

more gaps, less collisions, smaller resistance

Question 26

how does material affect resistance?

Answer 26

conductors - low resistance

insulators - high resistance

Question 27

what is ohms law?

Answer 27

voltage is directly proportional to current as long as temperature is constant

Question 28

what happens to resistance when you add components in series?

Answer 28

increases

Question 29

what happens to resistance when you add components in parallel?

Answer 29

decreases

Question 30

what are the I V characteristics if a resistor?

Answer 30

voltage is directly proportional to current

resistance is constant when a wire is at constant temperature

Question 31

what are the I V characteristics of a bulb/ lamp?

Answer 31

as voltage increases, current increases less and less

resistance is increasing because bulb is getting hot

Question 32

what are the I V characteristics of a diode?

Answer 32

diode has low resistance after a certain value
current increases dramatically as he voltage increases very little
resistance decreases

Question 33

what are the uses of thermistors?

Answer 33

fire alarms. Increased temperature would reduce resistance in a circuit. The current will increase and alarm goes off

Question 34

what are uses of an LDR?

Answer 34

night lights. When brightness decreases, resistance increases and this causes light to turn on

Question 35

what is power?

Answer 35

rate at which electrical energy is transferred to other forms of energy per second

Question 36

what is power measured in?

Answer 36

Watts (W)