
#1
Feb2310, 07:15 PM

P: 1

1. The problem statement, all variables and given/known data
The Helmholtz coil current = 2.45 A, the magnetic field = 1.91 x 10^(3) T, the accelerating voltage = 295 V, and the beam radius = .03m. a) Calculate the e/m ratio of an electron. Show that e/m = 2V / r²B² b) During the initial use of this experiment, physicists also knew the chargetomass ratio of a hydrogen ion, approximately 9.58 x 10^7 Coulombs/kg. If you had little knowledge of atomic structure, what two interpretations could you place on the differences between the two ratios? 2. Relevant equations PE = Ve KE = 1/2mv² Fmag = evB Fcent = mv²/r 3. The attempt at a solution a) Ve = 1/2mv² v = √(2Ve / m) ; v² = 2Ve/m Fmag = Fcent evB = mv²/r r = mv/Be I can't seem to get past this part of the derivation. I've tried subbing in √(2Ve / m) into r = mv/Be but it turns out too messy. b) I'm not too sure about the second part at all.. in what kind of context should I be thinking about the ratios? 


Register to reply 
Related Discussions  
Electron Charge to Mass Ratio  Introductory Physics Homework  7  
Basic physics in remote universe (proton/electron mass ratio)  Cosmology  1  
[SOLVED] Electromagnetism, calculate electron charge/mass ratio  Introductory Physics Homework  4  
Proton electron mass ratio  General Physics  3  
charge to mass ratio of an electron shot through a cathoderay oscilloscope  Introductory Physics Homework  2 