The affect of changing Light intensity on Resistance due to LDR

Click For Summary
SUMMARY

The discussion focuses on an experiment to measure how the resistance of a Light Dependent Resistor (LDR) changes with varying layers of tracing paper, specifically testing up to six layers. As more layers are added, light intensity decreases, resulting in increased resistance. Participants discuss the expected graph shape, measurement techniques for tracing paper thickness, and methods to demonstrate the directional spread of gamma rays. Key tools mentioned include an LDR, an ohm meter, and potentially vernier calipers for measuring paper thickness.

PREREQUISITES
  • Understanding of Light Dependent Resistors (LDR)
  • Basic knowledge of electrical resistance and Ohm's Law
  • Familiarity with graphing data and interpreting results
  • Experience with measurement tools such as vernier calipers
NEXT STEPS
  • Research the relationship between light intensity and resistance in LDRs
  • Learn about graphing techniques for experimental data analysis
  • Investigate methods for measuring material thickness accurately
  • Explore experimental setups to demonstrate the properties of gamma rays
USEFUL FOR

Students conducting physics experiments, educators teaching concepts of light and resistance, and anyone interested in practical applications of LDRs and radiation properties.

PhysicsLearne
Messages
9
Reaction score
0
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
 
Physics news on Phys.org
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
 

Similar threads

  • · Replies 14 ·
Replies
14
Views
3K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 42 ·
2
Replies
42
Views
3K
Replies
16
Views
2K
  • · Replies 4 ·
Replies
4
Views
3K
  • · Replies 7 ·
Replies
7
Views
3K
  • · Replies 20 ·
Replies
20
Views
2K
  • · Replies 3 ·
Replies
3
Views
6K
  • · Replies 21 ·
Replies
21
Views
3K
  • · Replies 2 ·
Replies
2
Views
37K