A-LEVEL Physics: 5.1.2: Current-Voltage Characteristics (SaveMyExams)

Question 1

Ohm’s law:

Answer 1

for a conductor at constant temperature, the current through it is proportional to the potential difference across it

V=IR

Question 2

in Ohm’s Law, what does constant temperature imply?

Answer 2

constant resistance

Question 3

Ohm’s law is represented by the equation:

Answer 3

V=IR

Question 4

I-V graph of a fixed resistor:

Answer 4

straight line graph

Question 5

ohmic conductor:

Answer 5

conductor that obeys Ohm’s law

Question 6

non-ohmic conductor:

Answer 6

conductor that does not obey Ohm’s law

Question 7

I-V graph of an ohmic conductor:

Answer 7

straight line through the origin

Question 8

what type of conductor is a resistor?

Answer 8

ohmic

Question 9

what type of resistor is a filament lamp?

Answer 9

non-ohmic conductor

Question 10

in an ohmic conductor, current & voltage are ___ proportional

Answer 10

directly

Question 11

in an ohmic conductor, current & resistance are ___ proportional

Answer 11

inversely

Question 12

semiconductor diode I-V graph:

Answer 12

horizontal line that goes sharply upwards

Question 13

filament lamp I-V graph:

Answer 13

S curve

Question 14

2 directions that current can flow through a diode: (2)

Answer 14

-forward bias

-reverse bias

Question 15

explain why filament lamp is a non-ohmic conductor: (3)

Answer 15

-as current increases, temp. of filament in the lamp increases, as more e- flow through it

-since filament is metal, the higher temp. causes inc. in resistance

-resistance opposes the current, causing the current to increase at a slower rate than the pd

Question 16

gradient of I-V graph:

Answer 16

resistance