Verification of inverse square law using photocell is straight line

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SUMMARY

The graph for the verification of the inverse square law using a photocell appears as a straight line due to the relationship between light intensity and the current flowing through the light-dependent resistor (LDR). The intensity of light entering the photocell frees electrons, reducing resistance and allowing current to flow. This process is discrete, meaning that the current is directly proportional to the intensity of light received, rather than following a curved relationship as one might expect from the inverse square law.

PREREQUISITES
  • Understanding of the inverse square law in physics
  • Knowledge of photocells and their operation
  • Familiarity with electrical resistance and current flow
  • Basic principles of electron behavior in conductive materials
NEXT STEPS
  • Research the principles of the inverse square law in different contexts
  • Explore the functioning of light-dependent resistors (LDRs) in detail
  • Study the relationship between light intensity and electrical resistance
  • Investigate the discrete nature of electron excitation in conductive materials
USEFUL FOR

Students of physics, electrical engineers, and anyone interested in the practical applications of photocells and the inverse square law.

XuFyaN
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why the graph for the verification of inverse square law using photocell is straight line instead of a curve ?
since intensity is inversely proportional to the distance then graph must be a curve, but why it is straight line ?
 
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XuFyaN said:
why the graph for the verification of inverse square law using photocell is straight line instead of a curve ?
since intensity is inversely proportional to the distance then graph must be a curve, but why it is straight line ?

This is because you are confusing the intensity of the source with the intensity of a reciever. A photocell works by allowing light into it. The light then gives energy to the electrons in the material. It does this to free the electrons from there bound state, so they can become "conduction electrons" and pass on a current. By "knocking off" the electrons, it reduces the resistance and allows a current to pass. The relationship between the current flowing through the LDR (photocell) is dependent on the reduction in resistance which is dependent of the intensity coming in, as it is a discrete process of either giving energy to conduction electrons, or simply not.
 

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