Electrical Circuits Physics.

Question 1

LDR

Answer 1

detect light,
as light intensity (or voltage of the light source) increases resistance decreases .

Question 2

Why does (r) decrease as (li/v) light intensity increase

Answer 2

produces more free electrons in LDR therefore needs less electrons for the same voltage

Question 3

Equipment needed to investigate LDR’s

Answer 3

Lamp
Battery
LDR
Ohmmeter - to measure the resistance
Circuit Wire - To transfer current to component
crocodile clips
ruler

Question 4

risks equippment

Answer 4

electrocution
Over heated equipment (lamp)

Question 5

Method of LDR’s

Answer 5

Turn the power-pack on to 2v and ensure the lamp is 5 cm away from the LDR.

Record the resistance on the ohmmeter.

turn the power-pack off allowing it to cool down

turn p-p back on and repeat steps for increasing voltages (L-intensities)