resistance and I-V characteristics

Question 1

what do ohmic conductors have

Answer 1

constant resistance

Question 2

what happens to the resistance of ohmic conductors

Answer 2

it doesn’t change with the current

Question 3

what are examples of ohmic conductors

Answer 3

wire or resistor

Question 4

at constant temp what happens to the current flowing through an ohmic conductor

Answer 4

it is directly proportional to the potential difference across it

Question 5

the resistance of what resistors and components change

Answer 5

diode or filament lamp

Question 6

what happens when electrical charge flows through a filament lamp

Answer 6

it transfers energy to the thermal energy store

Question 7

what happens to the current when the resistance increases with temperature

Answer 7

the current increases with the resistance, as the filament lamp heats up more the resistance increases

Question 8

for diodes what does the resistance depend on

Answer 8

the direction of the current

Question 9

what does the term “I-V characteristics” refer to

Answer 9

a graph that shows the current flowing through a component changes as the potential difference across it increases

Question 10

what do linear components have

Answer 10

I-V characteristics thats a straight line (eg. a fixed resistor)

Question 11

what do non linear components have

Answer 11

a curved I-V characteristic (e.g filament lamp or diode)

Question 12

what are the steps to find a components I-V characteristic

Answer 12

1) set up the suitable test circuit
2) vary the variable resistor , to alter current flowing through a circuit and the potential difference across the component
3) take several reading from the ammeter and voltmeter to see how the pd change
4)swap the wires connected to the battery, so the direction of current is reversed
5)plot a graph of current against voltage for the component