The affect of changing Light intensity on Resistance due to LDR

In summary: M BThere is no specific instrument, you could use a vernier callipers (sp?) to measure the thickness of the tracing paper.
  • #1
PhysicsLearne
10
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
 
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  • #2
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.
 
  • #3
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
 
  • #4
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.
 
  • #5
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
 

1. How does light intensity affect the resistance of a LDR?

As the light intensity increases, the resistance of a LDR decreases. This is because the LDR is made up of a semiconductor material that becomes more conductive in the presence of light, resulting in a decrease in resistance.

2. What is the relationship between light intensity and resistance in a LDR?

The relationship between light intensity and resistance in a LDR is inverse. This means that as one increases, the other decreases. So, as light intensity increases, the resistance of the LDR decreases and vice versa.

3. Can the resistance of a LDR be affected by factors other than light intensity?

Yes, the resistance of a LDR can also be affected by temperature, humidity, and the material composition of the LDR. However, the most significant factor that affects LDR resistance is light intensity.

4. How can we measure the resistance of a LDR in relation to light intensity?

The resistance of a LDR can be measured using a multimeter or ohmmeter. By connecting the LDR in series with a resistor and measuring the voltage drop across the LDR, we can use Ohm's law (V=IR) to calculate the resistance.

5. What are some real-world applications of the relationship between light intensity and LDR resistance?

LDRs are commonly used in automatic lighting systems, such as streetlights and security lights. They are also used in cameras to measure the amount of light and adjust the exposure accordingly. Additionally, they are used in solar panels to track the position of the sun and optimize energy production.

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