Charge to Mass Ratio question

Question

In my physics lab we experimented with a cathode ray tube between two electromagnetic coils to measure the charge to mass ration. If the earth's magnetic field is 0.5 x 10-4 Tesla pointing 60 degrees below the horizontal plane, what is the maximum percent error it may contribute to your results?

Answer 1

depends on whether the axis of the coils points vertical or horizontal

0.5E-4cos60 if horizontal

0.5E-4sin60 if vertical

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