A certain particle is sent into a uniform magnetic field, with the particle’s velocity vector perpendicular to the direction of the field. Figure 28-37 gives the period T of the particle’s motion versus the inverseof the field magnitude B. The vertical axis scale is set by , and the horizontal axis scale is set by what is the ratio m/q of the particle’s mass to the magnitude of its charge?

Physicist S. A. Goudsmit devised a method for measuring the mass of heavy ions by timing their period of revolution in a known magnetic field. A singly charged ion of iodine makes 7rev in a 45.0mT field in 1.29ms. Calculate its mass in atomic mass units.

Figure 28-23 shows a wire that carries current to the right through a uniform magnetic field. It also shows four choices for the direction of that field.

(a) Rank the choices according to the magnitude of the electric potential difference that would be set up across the width of the wire, greatest first.

(b) For which choice is the top side of the wire at higher potential than the bottom side of the wire?

A cyclotron with dee radius 53.0 cm is operated at an oscillator frequency of 12.0 MHz to accelerate protons.

(a) What magnitude B of magnetic field is required to achieve resonance?

(b) At that field magnitude, what is the kinetic energy of a proton emerging from the cyclotron? Suppose, instead, that B = 1.57 T.

(c) What oscillator frequency is required to achieve resonance now?

(d) At that frequency, what is the kinetic energy of an emerging proton?

(a) In Fig. 28-8, show that the ratio of the Hall electric field magnitude E to the magnitude E_c of the electric field responsible for moving charge (the current) along the length of the strip is

where is the resistivity of the material and n is the number density of the charge carriers. (b) Compute this ratio numerically for Problem 13. (See Table 26-1.)

Question: An electron has velocity as it enters a uniform magnetic field What are (a) the radius of the helical path taken by the electron and (b) the pitch of that path? (c) To an observer looking into the magnetic field region from the entrance point of the electron, does the electron spiral clockwise or counterclockwise as it moves?