Please answer relative to the rubric. Summer 2017 TR 8:00-10:30 am HW05 Name Do

Question

Please answer relative to the rubric.

Summer 2017 TR 8:00-10:30 am HW05 Name Do the problem as written in your textbook and use their numbers, not those on WebAssign. This should take very little extra time if you solved the webAssign problems using symbols and not numbers. Chapter 20, P34: In the simple mass spectrometer shown in Figure 20.101, positive ions are generated in the ion source. They are released, traveling at very low speed, into the region between two accelerating plates between which there is a potential difference Av. In the shaded region there is a uniform magnetic field B; outside this region there is negligible magnetic field. The semicircle traces the path of one singly charged positive ion of mass M, which travels through the accelerating plates into the magnetic field region, and hits the ion detector as shown. Determine the approximate magnitude of the magnetic field B, in terms of known quantities shown in Figure 20.101. Explain all steps in your reasoning. Accelerating plates Ion detector Ion Source AV .. . . F Magnetic field

Explanation / Answer

so, after accelerating by V voltage, KE of ions = qV [ where q is charge on the positive ion]
now, let velocity of ion after accelerating be v
then qvB = 2mv^2/d [ magnetic force on ion is equal to centripital force]
B = 2mv/dq
but 0.5mv^2 = qV [ m is mass of ion ]
so, v = sqroot(2qV/m)
B = 2m*sqroot(2qV/m)/dq = 2sqroot(2Vm/q)/d

here, V is vasccelerating potential
m is mass of ions
q is charge on ions
d is diameter of the circle as shown in the figure

if all the variables have SI units, the answer must be then in tesla

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---