How Does Liquid Depth Affect LDR Readings?

[RM-Smith]

1. The problem statement
I'm currently conducting an investigation into how a Light Dependent Resistor changes depending on the depth of a liquid above it. The experiment is pretty simple, however the write up is somewhat more problematic.
Firstly I'm asking whether I should read voltage, resistance or current from my multimeter
Secondly I have to find errors which may effect the results, explain them and collect further results to limit them, however I'm struggling to think of many, and how to limit them.

Homework Equations

The Attempt at a Solution

Question 1: I know I can use I=V/r, but really I need someone to let me know why I would measure in a particular one.
Question 2: Light from other sources is obviously a big one, and one which I can easily limit, and the factors involved in the opacity of the liquid is another (however I haven't chosen a liquid yet), but any other suggestions are greatly appreciated.
Any other advice would also be incredibly helpful, as this isn't my strongest aspect of physics.

Thanks in advance,
Robert

 

[NateD]

.Answer 1: You should measure voltage in this experiment as a Light Dependent Resistor is a voltage device, so measuring voltage gives you a direct indication of the amount of light the resistor is receiving.Answer 2: Other potential sources of error include temperature, humidity, the angle of the light source, and the size of the light source. To limit these errors, make sure to keep the temperature and humidity constant, position the light source directly above the LDR, and use a consistent size light source. Additionally, it may be helpful to take multiple readings from different depths and average them to get a more accurate result.