Construct suitable circuit and record your finding to illustarte the operational principle of the sensors: sound, light
Distance from light source (cm) - light intensity (lx)
0 - 1000
10 - 400
20 - 260
30 - 200
40 - 190
experiment involved moving a datalogger away from a lamp, measuring the light intesity the further we got away.
Attached constructed circuit.
The Attempt at a Solution
An LDR resistance changes with light. As light falls on the LDR it causes the electrons within the LDR to break free of their lattice allowing them to conduct electricity, therefore decreasing the overall resistance of the LDR. When no light falls on the LDR there are no/few free electrons within the LDR which can conduct electricity there fore there is a very high resistance
A voltage of V is passed through the circuit. As light falls on the LDR at 0cm away the light intensity is very high 1000lx therefore the resistance of the LDR will be low. A current of I is displayed on the ammeter when light intensity is 1000lx because the current through the LDR is less impeded. At 50cm away light intensity on the LDR is 180lx therefore the resistance of the LDR will be higher and the current will be impeded more therefore a lower current will be shown on the ammeter.
I am not sure if the circuit I have constructed is suitable as the other circuits I have found are very complicated.