V-I graphs

Question 1

Resistor

Answer 1

As V increases, I increased at constant rate

Voltage is directly proportional to current. Resistance stays constant.

Question 2

Filament lamp

Answer 2

V increases, I increased at decreasing rate.
as the current increases the filament heats up, increasing its resistance

Question 3

Diode

Answer 3

very little current flows until the threshold voltage is reached, after which the current increases rapidly. In the reverse direction, almost no current flows

Question 4

explain the movement of electrons in a filament lamp when the temperature is high

Answer 4

atoms vibrate more, more collisions with electrons. Requires more energy to push the current through, resistance increases.

Question 5

Explain why current remains at 0 until it can then flow

Answer 5

Current can only flow through a diode in one direction
At this point resistance is high

Question 6

How does length of the circuit affect resistance and current

Answer 6

Greater length= higher resistance as electrons pass through more resistor atoms. This decreases current .