A proton (q=1.6e-19, m=1.6e-27) is moving perpendicularly inside a magnetic fiel
ID: 1322756 • Letter: A
Question
A proton (q=1.6e-19, m=1.6e-27) is moving perpendicularly inside a magnetic field 500 gauss with energy 2.7 ev (1 ev=1.6e-19 j). FindGeometry of the path Radius of the path Time period of revolution Frequency of rotation A proton (q=1.6e-19, m=1.6e-27) is moving perpendicularly inside a magnetic field 500 gauss with energy 2.7 ev (1 ev=1.6e-19 j). Find
Geometry of the path Radius of the path Time period of revolution Frequency of rotation
Geometry of the path Radius of the path Time period of revolution Frequency of rotation
Explanation / Answer
particle moves in circular motion
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radius is obtained as from use KE = PE
0.5 mv^2 = eV
so speed v = sqrt(2eV/m)
v = sqrt(2 * 2.7 *1.6 e-19/1.6 e-27)
v = 2.32 *10^4 m/s
so
apply centripetal force = magnetic force
i.e mv^2/r = qvB,
where m = mass o the charged particle
v = velocity, r = radius ,
q = charge = 1.6*10^-19 C
B = magnetic field
so now , so as r = mv/qB
r = 1.67 e-27 * 2.32 e 4/(1.6e-19 * 500 e-4)
r = 4.83 mm
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T = 2piR/V
T = (2*3.14* 0.00483)/(2.32 e4)
T = 1.307 us
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f = 1/T
f = 1/1.307 e-6
f = 7.64 *10^5 Hz