J.J. Thomson determined the “charge-to-mass ratio” of the electron r = e/m by accelerating electrons through a voltage V
Posted: Wed May 18, 2022 4:36 pm
J.J. Thomson determined the “charge-to-mass ratio” of the electron r = e/m by accelerating electrons through a voltage V and then bending them in a magnetic field. The ratio is given by the formula 125 D2.V Ho = 411 10-7 N/A exactly 32. už · N2 d2. 12 The measurements are, respectively, the number of turns in a coil that produces the field, diameter of the coils, accelerating voltage, diameter of the electron's circular path in the field, current through the coils. N = 72 exactly D = 661 + 2 mm V = 45.0 + 0.2 V d = 91.4 + 0.5 mm I = 2.48 + 0.04 A e =r= m Find the relative (fractional) discrepancy (as a percentage), relative to the accepted value. (Look it up!) . Find the relative uncertainty (also a percentage) using the measurement relative uncertainties. Find the scaled discrepancy. That is, divide the two fractions (discrepancy by uncertainty) to express the discrepancy as a number of standard deviations (SDs). O Decide, based on this comparison, whether the measured and accepted values are consistent. If less than 1 SD, the two values seem consistent. If not...