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# Physics ISA - LDR Hypothesis Explanation Help watch

1. Hello. My Physics teacher is really bad and I'm stumped about how to explain my hypothesis for my ISA question. It's really important because I want to get full marks so I need to get this right. I've tried to search online but I'm really not sure what to put.

Here is my hypothesis: The resistance of a light dependent resistor decreases with increasing light intensity

So how would I explain this? Thank you!
2. Hiya,
When I did my physics ISA last year I looked at a past paper mark scheme to find out exactly how to word it for full marks. You have to start with you have to say something like 'I have researched many sources and have found a similar experiment/a website that said that.....' And then explain briefly how an LDR works (you can copy what the website says)
3. I believe that light has 5 letters and resistor has 8. 8-5=3 which is the number of letters in ISA. So maybe isa is the illuminati.
4. (Original post by VioletPhillippo)
Hiya,
When I did my physics ISA last year I looked at a past paper mark scheme to find out exactly how to word it for full marks. You have to start with you have to say something like 'I have researched many sources and have found a similar experiment/a website that said that.....' And then explain briefly how an LDR works (you can copy what the website says)
Hi... was the ISA hard or not that bad?
5. I have the same ISA as you I think!
6. (Original post by lordofthehumans)
Hi... was the ISA hard or not that bad?
I did the one about thermistors last year as I'm in year 12. I managed to get 60/60 by going over how to answer each question using past papers. The LDR one will be very similar so you'll be fine
7. (Original post by VioletPhillippo)
I did the one about thermistors last year as I'm in year 12. I managed to get 60/60 by going over how to answer each question using past papers. The LDR one will be very similar so you'll be fine
Wow!! Well done! Thanks
8. Did you ever get an explanation to the hypothesis?! I have paper 1 next week and that is my hypothesis! Thanks
9. Your idea is absolutely true! We need to expose them for who they really are.... Gather all the evidence you can yualwayslying you are soooooo smart 😱
10. hellu...ma nams billeh...isa eazeh..gut 60/50...2 gud..thunks, plez...kund rehguds...billeh
11. thenk u so much billeh much appreshiated

cind regerds
12. nuh prublm mehnumsnotbilleh, glud iz cud hulp plez
13. mor halp with jehsehessez plez
14. ohkay mehnamsnotbilleh. dunt woreh, iz gut aystah in orll ma jezeeseez. 2 gud.
15. woweh.. billeh weh doneh
16. i think we have the same bad teacher looool
17. (Original post by Joshua-P)
Hello. My Physics teacher is really bad and I'm stumped about how to explain my hypothesis for my ISA question. It's really important because I want to get full marks so I need to get this right. I've tried to search online but I'm really not sure what to put.

Here is my hypothesis: The resistance of a light dependent resistor decreases with increasing light intensity

So how would I explain this? Thank you!
Hi,

So this is like 4 months late and I do not know if you actually got the explanation but here is what I hypothesise>>

The resistance of the LDR decreases as the light intensity on the LDR increases because more electrons are induced in the current, hence more charge can be carried to the appliance.

If you look at Ohms Law> Voltage is the product of Current and Resistance. Rearranging that equation, resistance is equal to voltage divided by current. Therefore, according to Ohms Law, as current increases, the resistance must decrease.

Hopefully this is right, otherwise Im definitely gonna mess up my paper 1 next week.
18. Hi have u sat ur physics ISA on Ldrs?
19. (Original post by alicexxx22222)
Hi have u sat ur physics ISA on Ldrs?
Yep! Got full marks.
20. (Original post by Joshua-P)
Yep! Got full marks.

my hypothesis is this
If i decrease the distance of the light from the resistor i would be increasing the light intensity yet decreasing the resistance

Is that okay?

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Updated: February 6, 2016
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