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## Homework Statement

*Main ideas in bold[/B]

Investigation of the inverse square law of light radiated from a light bulb. (done method, diagram, results and graph)

Independent variable = the distance from the LDR (cm)

Dependent Variable = resistance (k/ohms)

Brief method: using an LDR, bulb, power supply and a resistance metre, get a range of results of the resistance by moving the bulb closer and closer to the LDR e.g. I did first reading 2cm from LDR and then went up by 2cm each time to 20cm. Then plot results on a graph and use it to verify the theory p=k/[d][2].

The Graph is nearly a straight line positive correlation where it sort of curves in the positive direction from 2-6cm/20cm, then is pretty much linear,

**not sure if this is how its meant to be.**

**The main issue I have is how to find (k), the constant and how to use my results and graph to verify the theory.**

ps. that method isn't my original I just tried to summarise as it would have been long

## Homework Equations

Theory being p=k/[d][2] where: p= intensity d=distance between the LDR and the bulb and k= constant

Inverse square law - I ∝ 1/[d][2]

## The Attempt at a Solution

To be honest I haven't done this kind of practical in a long time due to it being the first one of the year so I don't know where to start but i think I need some help with the first step or 2 and I'll remember.