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    Two electrons x and y travel at right angles to a uniform magnetic field. X experiences a magnetic force, Fx and Y experiences magnetic force Fy.

    What is the ratio Fx/Fy if the kinetic energy of X is half that of Y ?

    a) 1/4
    b) 1/2
    c) 1/root 2
    d) 1
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    Sorry you've not had any responses about this. Are you sure you've posted in the right place? Here's a link to our subject forum which should help get you more responses if you post there.

    You can also find the Exam Thread list for A-levels here and GCSE here. :dumbells:


    Just quoting in Puddles the Monkey so she can move the thread if needed
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    (Original post by Puddles the Monkey)
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    C, half of 1/2mv^2 with constant mass (as both electrons) means that velocity is reduced by a factor of 1/sqrt(2)
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    (Original post by 16characterlimit)
    C, half of 1/2mv^2 with constant mass (as both electrons) means that velocity is reduced by a factor of 1/sqrt(2)
    but it says the ratio of the forces not the ratio of the velocity
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    (Original post by civ1)
    but it says the ratio of the forces not the ratio of the velocity
    My mistake, luckily since F=Bqv

    Fx/Fy = Bqv/Bq(v/sqrt(2)) = 1/sqrt(2)

    So still C.
 
 
 
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