10 Circuits

Question 1

what is 1 amp equal to in coulombs?

Answer 1

1 amp = 1 coloumb flowing per second

Question 2

what does voltage measure? [hint: charge]

Answer 2

how much energy the charge has as it flows around the circuit

Question 3

what is voltage measured in?

Answer 3

volts

Question 4

what is current measured in?

Answer 4

amps

Question 5

what is resistance measured in?

Answer 5

ohms

Question 6

what is 1 volt euqal to in terms of joules AND coloumbs?

Answer 6

1 volt = 1 joule of energy per coloumb of charge flowing

Question 7

what is equal to 1 joule of energy per coloum of charge flowing?

Answer 7

1 volt

Question 8

what pushes charge around a circuit?

Answer 8

voltage

Question 9

what is a current created by?

Answer 9

voltage pushing current around a circuit

Question 10

what happens to current when voltage increases?

Answer 10

current also increases

Question 11

give the symbol equation linking voltage, current, and resistance

Answer 11

V=IR

Question 12

what does resistance do?

Answer 12

opposes flow of current around a circuit

Question 13

what happens to the current when resistance increases for a given voltage?

Answer 13

current decreases.

Question 14

what must resistance do to maintian a given current, and what happens to voltage?

Answer 14

resistance increases. voltage must be increased.

Question 15

what does an ammeter measure

Answer 15

current

Question 16

what is current measured by

Answer 16

an ammeter

Question 17

what is voltage measured by

Answer 17

voltemeter

Question 18

what does a voltmeter measure?

Answer 18

voltage

Question 19

where does the ammeter go in a circuit>

Answer 19

in series

Question 20

where doe a voltmeter go in a circuit?

Answer 20

in parallel

Question 21

is current the same or different in each component in a series circuit?

Answer 21

same

Question 22

is voltage the same or different in each component in a series circuit?

Answer 22

different

Question 23

what happens when one component fails in a series circuit?

Answer 23

all other components fail

Question 24

is current the same or different in each component in a parallel circuit?

Answer 24

different

Question 25

is voltage the same or different in each component in a parallel circuit?

Answer 25

the same

Question 26

what happens to the components in a parallel circuit when a component in the circuit fails?

Answer 26

all the other components are unaffected

Question 27

what is the role of a diode?

Answer 27

to ensure current flows in 1 direction

Question 28

why is the line flat/shallow in a graph depicting the resistance of the diode? (in terms of current)

Answer 28

as current is flowing in the 'wrong direction'

Question 29

what happens to the resistance when the line is flat/shallow in a graph depicting the resistance of the diode?

Answer 29

resistance is infinite/very high

Question 30

what does a steep/vertical line show in a graph depicting the resistance of the diode? (in terms of current)

Answer 30

current flowing in the 'correct' direction

Question 31

what happens to the resistance when the line is steep.vertical in a graph depicting the resistance of the diode?

Answer 31

resistance is zero

Question 32

what is the name for an as-shaped curve in a filament bulb diagram (showing resistance)

Answer 32

ogive

Question 33

what happens to the line in a V-I graph (of a bulb) when temp. increases resistance?

Answer 33

the line is flat/flattens

Question 34

what happens to the graph line when both current and temperature are low on a bulbs graph?

Answer 34

it is steep

Question 35

what does a curved line show on a V-I graph?

Answer 35

resistance is not constant

Question 36

state the connection between voltage and temperature on a filament bulb resistance graph

Answer 36

- as voltage increases, temperature increases (because the lamp heats up)

Question 37

what causes the line to flatten on an ogive curve on a V-I graph, and what is the cause of that cause?

Answer 37

increase in resistance, caused by an increase in voltage and temperature

Question 38

what does no voltage equal in terms of current?

Answer 38

no current

Question 39

what does no current equal in terms of voltage?

Answer 39

no voltage

Question 40

what does a symmetrical line show on a V-I graph? [2 SEPERATE points]

Answer 40

- resistance is constant - resistance is the same in both directions

Question 41

what does a striaght line with a constant gradient show on a V-I graph?

Answer 41

constant resistance

Question 42

what is Ohms' law?

Answer 42

R=V/I

Question 43

what is a thermistor?

Answer 43

a temerpature-sensitive resistor

Question 44

what happens as resistance decreases in a thermistor?

Answer 44

temperature increases

Question 45

what are thermistors made of?

Answer 45

lead

Question 46

what happens to the resistance of a thermistor when hot?

Answer 46

low resistance

Question 47

what does a thermistor look like?

Answer 47

a resistor with an ice-hockey stick shoved in it

Question 47

what happens to the resistance of a thermistor when cold?

Answer 47

high resistance

Question 48

what does LDR stand for

Answer 48

Light-dependent-resistor

Question 49

what happens to the resistance in an LDR as light intensity changes?

Answer 49

resistance changes

Question 50

do LDRs have high resistance in bright light?

Answer 50

no.

Question 51

what sort of conditions do LDRs have bright reisistance in?

Answer 51

the dark

Question 52

what happens as light intensity increases in an LDR?

Answer 52

reistance decreases.

Question 53

desribe the resistance curve of a diode

Answer 53

flat then _) [curve upwards]

Question 54

describe the resistnace curve of a bulb

Answer 54

ogive (s-shape)

Question 55

describe the resistance curve of a resistor

Answer 55

positive linear

Question 56

descirbe the relationship beween the resistance of the LDR and light intensity [2 points]

Answer 56

M1 as light intensity increases, the resistance of the LDR decreases M2 non-linearly

Question 57

how many volts does DC deliver in UK homes

Answer 57

230 V

Question 58

if there is a thermistor before a fixed resistor in series, explain why the voltage across the fixed resistor changes when the thermistor is in COLD water [3 points]

Answer 58

M1 resistance of thermistor increases M2 so current through circuit also increases M3 voltage across fixed resistor decreases