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Help A2 physics planning exercise

  1. May 18, 2004 #1
    Help!! A2 physics planning exercise!!!!!!!

    Is anyone doing the A2 OCR physics planning exercise? I have just finished the AS one that soooooo many people have been talking about (I am resitting it from last year!) but now have the A2 one to do.

    It is the one with the surface temperature of the glass envelope of a light bulb.

    Does anyone know how to cool the bulb down between experiments?

    Help would be much appreciated! :biggrin: before I start crying :cry: !!!!!

    I am using thermocouples if any one is stuck with the kind of thermometer to use!
  2. jcsd
  3. May 18, 2004 #2
    Can you write down a full description of the exercise, due to help you better?
  4. May 18, 2004 #3
    Ok, ta!

    A manufacturer of filament lamps for use as a night light in childrens bedrooms is concerned about the surface temperature of the glass envelope after the lamp has been left on for some time. The surface temp must not be too high, otherwise danger of burns or fire resulting from accidental contact with the surface of the lamp. However, it is important that the power output from the lamp should not be too small, otherwise lamp will be too dim to be useful.

    Design a laboratory experiment to investigate how th esurface temperature of the glass envelope of a filament lamp varies with electrical power delivered to the lamp. Draw a diagram(s) showing how the equipment would be arranged. In your account, you should explain:

    a) procedure to be followed

    b)your choice of the type of thermometer used to measure the surface temperature of the lamp

    c) how electrical power would be measureed

    d) any relevant safety precautions you may take when carrying out the experiment

    e) any particular features of your design that may improve the accuracy of your experiment
  5. May 20, 2004 #4
    I'm doing the same one as you. You shouldn't (I don't think) have to cool the bulb down between experiments. If you start by using a low voltage (thus low power), the lamp won't heat up as much as when you use a higher voltage.

    And i was wondering if you could help me!!! I can't find a site in easy English to tell me how a thermocouple works. I know you have to use a data logger on a PC to record the temps, and I was going to use a standard type K, using a self-adhesive band that goes round the bulb... but... I need to say how they work. And I have no idea!!

    And also, how do you show a thermocouple in the diagram?!
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