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    http://www.ocr.org.uk/download/pp_09...ce_f211_01.pdf

    Question 1aiii)

    Actual Size = Image Size/Magnification

    Image Size = 15mm x 1000 (to conver to micrometers) = 15000

    Mark scheme says divide by 4000, but why because it doesnt say magnification is 4000 :/


    Thanks!
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    You have to calculate the magnification using the scale.
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    The scale is 20 um which is 20micrometers - how would i do that?
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    The magnification is what the scale line thing represents, divided by how long it actually is (in mm converted to micrometres), then put that in the formula

    EDIT: or maybe its the other way round :o: as in how long it actually is, divided by what length it represents :o: I'm gonna get my practice paper out, i'll tell you in a sec
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    So if the whole cell is 75mm x 1000 = 75000 micrometers then divide that by 20 which is 3750 micrometers - which is the magnifcation? P:
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    okay, magnification is the length of the scale bar thing, divided by the length it represents
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    There's a link at the top of the post
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    (Original post by Sadbunny11)
    The scale is 20 um which is 20micrometers - how would i do that?
    Is that what it represents? You have to measure the scale line with a ruler and see how long it is, convert that to um, then divide that by 20um. Are you doing OCR Jan 09 by any chance?
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    Yep, done that - i think i got the right answer now.

    And yep
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    I got my teacher to help me with that question :o:
    he did some of it for me:

    the scale line is 80mm and that represents 20 micrometres
    magnification = image size divided by actual size, so thats 80,000 micrometres (converting 80mm to um), divided by 20 micrometres, which is 4000 micrometres. hope that helps
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    (Original post by Sadbunny11)
    Yep, done that - i think i got the right answer now.

    And yep
    WOOOOOOOOO, congrats.
    This reminds me... I need to do some biology revision good luck with your exams!
 
 
 
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