91影视

In New Hampshire the average horizontal component of Earth鈥檚 magnetic field in 1912 was $\mathbf{16}\mathbf{}\mathit{渭}\mathbf{T}$, and the average inclination or 鈥渄ip鈥� was $\mathbf{73}\mathbf{掳}$. What was the corresponding magnitude of Earth鈥檚 magnetic field?

Figureis a one-axis graph along which two of the allowed energy values (levels) of an atom are plotted. When the atom is placed in a magnetic field of $\mathbf{0}\mathbf{.}\mathbf{500}\mathbf{}\mathit{T}{\mathit{E}}_{\mathbf{2}}$, the graph changes to that of Figure bbecause of the energy associated with${\stackrel{\mathbf{鈫�}}{\mathbf{渭}}}_{\mathbf{o}\mathbf{r}\mathbf{b}}\mathbf{.}\stackrel{\mathbf{鈫�}}{\mathbf{B}}$. Level ${\mathit{E}}_{\mathbf{1}}$is unchanged, but level splits into a (closely spaced) triplet of levels. What are the allowed values of${\mathit{m}}_{\mathbf{1}}$associated with (a) Energy level ${\mathit{E}}_{\mathbf{1}}$and (b) Energy level ${\mathit{E}}_{\mathbf{2}}$? (c) In joules, what amount of energy is represented by the spacing between the triplet levels?

If an electron in an atom has an orbital angular momentum with$\mathit{m}\mathbf{=}\mathbf{0}$, what are the components (a) ${\mathit{L}}_{\mathbf{o}\mathbf{r}\mathbf{b}\mathbf{,}\mathbf{z}}$and (b)${\mathit{渭}}_{\mathbf{o}\mathbf{r}\mathbf{b}\mathbf{,}\mathbf{z}}$? If the atom is in an external magnetic field$\stackrel{\mathbf{鈫�}}{\mathbf{B}}$that has magnitude$\mathbf{35}\mathbf{}\mathbf{mT}$and is directed along the z axis, what are (c) the energy${\mathit{U}}_{\mathbf{o}\mathbf{r}\mathbf{b}}$associated with$\stackrel{\mathbf{鈫�}}{{\mathbf{渭}}_{\mathbf{o}\mathbf{r}\mathbf{b}}}$and(d) the energy${\mathit{U}}_{\mathbf{s}\mathbf{p}\mathbf{i}\mathbf{n}}$associated with$\stackrel{\mathbf{鈫�}}{{\mathbf{渭}}_{\mathbf{s}}}$? (e) If, instead, the electron has$\mathit{m}\mathbf{=}\mathbf{-}\mathbf{3}$, what are (e)${\mathit{L}}_{\mathbf{o}\mathbf{r}\mathbf{b}\mathbf{,}\mathbf{z}}$? (f) ${\mathit{渭}}_{\mathbf{o}\mathbf{r}\mathbf{b}\mathbf{,}\mathbf{z}}$(g) ${\mathit{U}}_{\mathbf{o}\mathbf{r}\mathbf{b}}$and (h)${\mathit{U}}_{\mathbf{s}\mathbf{p}\mathbf{i}\mathbf{n}}$?

What is the energy difference between parallel and antiparallel alignment of the zcomponent of an electron鈥檚 spin magnetic dipole moment with an external magnetic field of magnitude0.25 T, directed parallel to the zaxis?

(a) What is the measured component of the orbital magnetic dipole moment of an electron with${\mathit{m}}_{\mathbf{l}}\mathbf{=}\mathbf{1}\mathbf{?}$(b) What is the measured component of the orbital magnetic dipole moment of an electron with${\mathit{m}}_{\mathbf{l}}\mathbf{=}\mathbf{-}\mathbf{2}\mathbf{?}$

An electron is placed in a magnetic field $\stackrel{鈫�}{B}$ that is directed along a$z$axis. The energy difference between parallel and antiparallel alignments of the $z$component of the electron鈥檚 spin magnetic moment with$\stackrel{鈫�}{B}$is$6.00脳{10}^{-25}$J. What is the magnitude of$\stackrel{鈫�}{B}$?

Assume that an electron of mass mand charge magnitude emoves in a circular orbit of radius rabout a nucleus. A uniform magnetic fieldis then established perpendicular to the plane ofthe orbit. Assuming also that the radius of the orbit does not change and that the change in the speed of the electron due to fieldis small, find an expression for the change in the orbital magnetic dipole moment of the electron due to the field.

Assume that an electron of mass mand charge magnitude emoves in a circular orbit of radius rabout a nucleus. A uniform magnetic field $\stackrel{鈫�}{B}$is then established perpendicular to the plane of the orbit. Assuming also that the radius of the orbit does not change and that the change in the speed of the electron due to field $\stackrel{鈫�}{B}$ is small, find an expression for the change in the orbital magnetic dipole moment of the electron due to the field.

A Gaussian surface in the shape of a right circular cylinder with end caps has a radius of 12.0 cmand a length of 80.0 cm. Through one end there is an inward magnetic flux$\mathbf{25}\mathbf{.}\mathbf{0}\mathbf{}\mathit{渭}\mathit{W}\mathit{b}$. At the other end, there is a uniform magnetic field 1.60 mT, normal to the surface and directed outward. What are the (a) magnitude and (b) direction (inward or outward) of the net magnetic flux through the curved surface?

Figure 32-21 shows, in two situations, an electric field vector $\stackrel{\mathbf{鈬赌}}{\mathbf{E}}$and an induced magnetic field line. In each, is the magnitude $\stackrel{\mathbf{鈬赌}}{\mathbf{E}}$increasing or decreasing?