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Homework Help: Urgent help needed! Sensor coursework

  1. Nov 7, 2005 #1
    Hi everyone!

    Im new here and i urgently need help from anyone whos done an OCR Physics sensor coursework. Im not the brightests bulb in the box in physics and i need to essemble a sensor (potentiometer, thermocouple, resistance bridge or a strain gauge) i was told by the teacher if i wasnt confident, to not do a photo sensor, LDR or a light sensor (i think there prety much the same thing!). But im desperate to get good marks and i dont know how! What sensor should i choose that isnt too simple and unimpressive that wont take a fool like me 2 hours to essemble? Could anyone draw me a sensor circuit diagram? What practical implication can the sensor that i have chosen have? should i compare two different sensors?
    Im realy in the dark, its all so confusing. If i ask the teachers they said they would mark me down. Please, please, please help me. I beg you all...:confused: :yuck: :surprised
  2. jcsd
  3. Nov 7, 2005 #2
    Look son firstly, are you sure its an OCR coursework and not an Advancing Physics? Secondly i have done this coursework just today lol so here goes.

    What i did was to use a series circuit with a power pack, fixed resistor, rotary potentiometer cting as the variable resistor, as shown below

    | |
    | Ammeter
    | -Voltmeter-- - --Voltmeter-- |
    -------Fixed resistor------rotary potentiometer---

    So with this circuit i could measure the current, voltage across fixed resistor, voltage across potentiometer. I took reading at every 10 degree angle of the rotary pentiometer. By creating this circuit, you have basically created a potential divider which is a circuit which has two resistors in series and one being a variable resistor andb changing the resistance on this it is possible to change the voltage. This is used when for example an appliance needs 6V and u have a 9V source for example. Now i myself am not sure if the above is completely right but i hope its been of some help, btw what city u in?

    sorry cant make the circuit digram work lol.
  4. Nov 9, 2005 #3
    Cheers mate any help is good help at the momment, im in bristol in BGS, i dont know if you know it. Thankyou so much with your advice. In what part of the country do you live in?
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