The affect of changing Light intensity on Resistance due to LDR

AI Thread Summary
The discussion centers on an experiment investigating how the resistance of a light-dependent resistor (LDR) changes with varying layers of tracing paper, which reduces light intensity. Participants inquire about the expected shape of the graph plotting tracing paper layers against resistance, with suggestions that it may not be a straight line. To measure the thickness of tracing paper, one method proposed is to stack multiple sheets and measure the total thickness, then divide by the number of sheets, though more precise tools like vernier calipers are also recommended. The conversation also touches on the need for clarity on how to experimentally demonstrate the directional spread of gamma rays. Overall, the focus is on practical experimentation and measurement techniques in physics.
PhysicsLearne
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I've got an experiment coming up where I have to find out how the resistance in a circuit changes as more layers of 'tracing paper' are added onto a LDR i.e. as more paper is added the light intensity will fall and as a result the resistance through the circuit will increase.

I am testing for up to 6 tracing papers.

A few questions if any of you could help:

On a graph of tracing paper(s) on the x axis, against resistance on the y axis, can I expect to see a straight line or more a curved graph?

How could you measure the thickness of a tracing paper (which apparatus?)

How could you test (by an experiment) that gamma rays spread out in different directions?

Thanks a lot

Mark B
 
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PhysicsLearne said:
I've got an experiment coming up where I have to find out how the resistance in a circuit changes as more layers of 'tracing paper' are added onto a LDR i.e. as more paper is added the light intensity will fall and as a result the resistance through the circuit will increase.

I am testing for up to 6 tracing papers.

A few questions if any of you could help:

On a graph of tracing paper(s) on the x axis, against resistance on the y axis, can I expect to see a straight line or more a curved graph?

How could you measure the thickness of a tracing paper (which apparatus?)

Mark B

Simple. LDR, Ohm meter, tracing paper, Room with lights on ceiling. try it!

Experiment is what science is all about.
 
bjacoby said:
Simple. LDR, Ohm meter, tracing paper, Room with lights on ceiling. try it!

Experiment is what science is all about.

Hi there,

Thanks a lot for your response. Is your answer in response to the question about how to prove gamma rays spread out in different directions?

Could you help with the other questions if possible too?

Many thanks

M B
 
One way to measure the thickness of the tracing paper would be to get a big clump of it together (say like 100 sheets), measure the thickness of all of that and divide it by how many you have (in this case, 100).

It wouldn't be 100% accurate, but that's the only way I can think of doing it.
 
Epic Sandwich said:
One way to measure the thickness of the tracing paper would be to get a big clump of it together (say like 100 sheets), measure the thickness of all of that and divide it by how many you have (in this case, 100).

It wouldn't be 100% accurate, but that's the only way I can think of doing it.

Hi there,

Is there any specific instrument though? Vernier callipers (sp?) I was told possibly?

Cheers
 

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