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A-Level Physics - [Question] Watch

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    How many electrons flow past a point each second in a 5.0mA electron beam?
    I used I=Q/T
    I = 0.005 A
    Q =
    T = 1
    so Q = 0.005 C
    right?
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    That seems correct.
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    (Original post by JustasB)
    That seems correct.
    I got the answer it was just telling me it was wrong as I had
    3.13 instead of 3.1

    Thanks
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    (Original post by AdeptDz)
    I got the answer it was just telling me it was wrong as I had
    3.13 instead of 3.1

    Thanks
    The answer was to 2 significant figures, so the answer of 3.13 is correct but it should be rounded to the correct number of significant figures.
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    (Original post by JustasB)
    The answer was to 2 significant figures, so the answer of 3.13 is correct but it should be rounded to the correct number of significant figures.
    Thanks
    Do you have an idea on this question:
    Alpha particles have twice the charge of an electron. What is the current caused by a radioactive source which emits 3000 alpha particles per second, to 3 significant figures?

    First I found out the charge which is 3.2*10^-19 (For one alpha particle) then I multiplied it by 3000 to get charge for 3000 alpha particles which is 9.6x10^-16 C now i used I = Q/T
    so I would equal 9.6 x 10^-16 aswell but i'm not sure what to do now or what i done wrong as this answer is incorrect
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    (Original post by AdeptDz)
    Thanks
    Do you have an idea on this question:
    Alpha particles have twice the charge of an electron. What is the current caused by a radioactive source which emits 3000 alpha particles per second, to 3 significant figures?

    First I found out the charge which is 3.2*10^-19 (For one alpha particle) then I multiplied it by 3000 to get charge for 3000 alpha particles which is 9.6x10^-16 C now i used I = Q/T
    so I would equal 9.6 x 10^-16 aswell but i'm not sure what to do now or what i done wrong as this answer is incorrect
    oh wow, it is correct just not to 3 sig. fig. once again.
    Keep making the same mistake, my bad!

    Edit:
    Do you know if i have to always use correct sig. fig. in the exam? (AQA if it helps)
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    (Original post by AdeptDz)
    oh wow, it is correct just not to 3 sig. fig. once again.
    Keep making the same mistake, my bad!

    Edit:
    Do you know if i have to always use correct sig. fig. in the exam? (AQA if it helps)
    Use the same number of significant figures as given in the question.
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    (Original post by JustasB)
    Use the same number of significant figures as given in the question.
    okay thanks
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    Did you get these questions on Isaac physics because I have been set this board and I literally have no clue! Hell
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    (Original post by Mossie99)
    Did you get these questions on Isaac physics because I have been set this board and I literally have no clue! Hell
    Ye I did ; was a while back though


    Posted from TSR Mobile
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    (Original post by AdeptDz)
    Ye I did ; was a while back though


    Posted from TSR Mobile
    Found out I was doing the same mistake as you with my sig figs! Gets very frustrating when it continuously says incorrect! Thanks anyway
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    (Original post by AdeptDz)
    I got the answer it was just telling me it was wrong as I had
    3.13 instead of 3.1

    Thanks
    How did you get the answer of 3.13? I've tried for a while but can't get it.
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    (Original post by Elementa)
    How did you get the answer of 3.13? I've tried for a while but can't get it.
    Charge / Charge on an electron
    0.005/1.6x10^(-19)
    I'm guessing that is what I done
    and that gives you 3.13x10^16

    Sorry for the late reply
 
 
 
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