Questions on Controlled Assessment
Light Dependent Resistors (Section 1)
1. Write down your hypothesis. Explain why you made this hypothesis.
When it is day there is more light hitting the LDR and so its resistance decreases and the light turns off. When it is night there is less light so the LDR has higher resistance and the light turns on.
When light shines on a Light Dependent Resistor, electrons are released and the current can get larger. So as the light intensity increases, more electrons are released and the resistance decreases. As the light intensity decreases, less electrons are released and the resistance increases.
2. Think about the research you did to find how to test your hypothesis.
Identify two sources you used for your research.
Source One: www.gcsescience.com/pe27.html
Source Two: www.passmeexams.co.uk/GCSE/physics/diodes/-LDR-thermistors.html Compare the usefulness of the two sources.
Source Two is much more useful than Source One because although Source One has diagrams and explanations, Source Two has clearer diagrams than Source One. Source Two has more and clearer text than Source One which makes it much easier to understand than Source One. Source Two also compares the LDR to a Thermistor.
3. In this question you will be assessed on good English, organising information clearly and using specialist terms where appropriate.
From the research you have done, describe in detail how you are going to do your investigation.
You should include:
The equipment you plan to use
How you will use the equipment
The measurements you are going to make
How you will make the investigation a fair test
A risk assessment
The equipment I plan to use includes a Multimeter, a Light Dependent Resistor, A clamp, A lamp & bulb, Some wires, A standard ruler, and some Crocodile Clips.
The control variables are the ones that do not change. The control variables include the bulb used in the lamp, the ruler, and the same Multimeter will be used