ohmic and non-ohmic conductors

Question 1

in ohmic components which two variables are directly proportional

Answer 1

current and potential difference

Question 2

if current and potential difference are directly proportional, what does it tell us about the resistance

Answer 2

it is constant

Question 3

name 4 non-ohmic conductors

Answer 3

filament bulbs, diodes, thermistors, LDRs

Question 4

why are filament light bulbs non-ohmic

Answer 4

current, temperature, resistance all increase

Question 5

describe the relationship between current and potential difference for a diode

Answer 5

current only flows in one direction and has a very high resistance in the other direction

Question 6

describe the relationship between temperature and resistance in a thermistor

Answer 6

as temperature increases resistance decreases

Question 7

state on use of a thermistor

Answer 7

thermostat

Question 8

describe the relationship between light intensity and and resistance in a LDR

Answer 8

Light intensity increases and resistance decreses

Question 9

state one use of a LDR

Answer 9

switching lights on when it gets dark eg. street lamps

Question 10

what does ohmic mean

Answer 10

if as voltage across the resistor is increased, a graph of voltage versus current shows a straight line (indicating a constant resistance)