Does Huygens’ principle apply to sound waves? To water waz ,3 d0wakj*;x9z4;bxym tr edkdc ;1(erei3kves? Explain.

What is the evidence that light is ene*bjl3hr .f+7 rhxjho 9rgy?

Why is light sometimes described igio kz)*:i4 vas rays and sometimes as waves?

We can hear sounds around corners, but we c/e 0e qy)off8 pf:9m4*acg gacannot see around corners; yet both sound and light are waves. Explain the differenccfag84ay0 ff/ oq :ee *mpc)9ge.

If Young’s double-slit experiment were submerged in water, how woeit*0dza(c8 c+ j0uz9f 3wlb zuld the fringe pzc d c*utl0zea9fb j3i+8z0 (wattern be changed?

Monochromatic red light is incident on a double slit,q35pfwfa gaxl,,cya- 3(fv u : and the interference pattern is viewed on a screen,53-fqufgcw3 v:aal a(xyf, p some distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interferkzaja5 diru7 shrra-rn 6r7 ltw(5l6l7,. v) ie if their path leng d6,wru6arlt7ii) ( ha.vrjk7n5ra-s l7r zl5ths differ by how much?

Why was the observation of the double-slit interference pattern mj3e (u vro -js c23ok6lx1fkz:ltq+dtv24p :lore convincing evidence for the wave theory of lirl t(t2:3-pjoo4zquf6j+ xkvkcdl3l ev 2s: 1 ght than the observation of diffraction?

Compare a double-slit experiment)p hx 6v(7 tcukv9*znd for sound waves to that for light waves. Discuss the similarh ntzkp7c)(*uvvd6 x9ities and differences.

Why doesn’t the light 89 b/zgzeh x*2ssr)gwfrom the two headlights of a distant car produce an interference patr9)b shs *z /wzx8geg2tern?

Suppose white light falls on the two slits of Fig. 24–7, butq ce/i7d cd.e 2sh eyxp0513lc one slit is covered by01e pci3ql.75ccyd x/shed2e a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes thfhpdy4g)uj*.5, gltc*b ap3urough a flat piece of window glass, it is not broken dow,t* *u.hclp g3pbaf4)d5yg jun into colors as it is by a prism. Explain.

For both converging and divergingpx 5ju e+(ctf0nv.eg+ lenses, discuss how the focal length for red lig(+ev .xg pnjtuf5+0c eht differs from that for violet light.

A ray of light is refracted throufj-p;3cwkw.nk0 c a)npfa0. m ka4 u.kgh three different materials (Fig. 24–55). Rank the materials according to their index of refraction, l3j0ak.kc )kp. unpma.;0cw- wak n f4feast to greatest.

Hold one hand close to your eye anwma1z*cnme-6qfw +h1d focus on a distant light source through a narrow slit between two fingers. (Adjust your f*w mhq1e+z61nwc-a fmingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern v.hoqn(3cnc5a0 s. ;fqkun x)of a single slit if the whole apparatus is immersed in (a) wa 3.xa5v;su )noc qnckf(q 0n.hter, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is (glt/.d +z2afoswwvt5 glqh; fg3(/wthe effect of increasing (a) the slit width, and (b) the ;dt5/fwq( t3zf2 +wovg g.g w(l/slahwavelength?

What is the difference in the interference patterns formed (a) by two slit4.wt2wq; wwuts $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (a) mfjq ni7lpsg) nvmf07q0*2 gb :any slits, (b) closely spacenmf2b vp qs gl0f:70n i)g7jq*d slits?

White light strikes (a) a diffraction grating, and (b) a prism. A r2z/ ocz wr 1-nj+eb- u)qs8 q9u3ljoyxainbow appears on a wall just below the direction of the horizontal incident beam in each casenj8osj3b )1r-yc/+ql ez9uo- zx u2wq . What is the color of the top of the rainbow in each case? Explain.

For light consisting of wag;l81 evum4fz- ov/mrtv3u5 cvelengths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the;u3-flzr gou5vv/m8 1v4 tc em slit spacing?

Why are interference fringes noticeable only for a thin film l(nz;j e:y-)vsf mf: otike a soap bubble and not for a thick piece of glass, )vfzo(:t: ;jy-s enfmsay?

When a compact disk (CD) is held atyazde ()pur; v+ 7cj( 76rrkdf an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used 6za7+)d ; yru7kpcrjd fve((r?

Why are Newton’s rings (Fig. 24–31c 9cmavf fry3g/3tj1/p ,ddc5) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. Wpysg2kqw*g2) 1hp 9o:x v4zjghat wavelengthsg29 z:hv)yxo j2p gqw1sk4p*g do you suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright a;s 9nctis 44tibbu20f t its edges, where its thickness is much less than the wavelengths of visi9 4 utnt;2sbis0i4b cfble light. What can you say about the index of refraction of the oil?

What does polarization*r ssxh3ar 1q. tell us about the nature of light?

Explain the advantage of polarized sunglasses over normal tinted sum g3woiv jkq0-;6k6aunglasses.

How can you tell if a pair of sunglasses is polarizing or c7(buk7 elfh (el-ot y00prv+not?

Two polarized sheets rotated at an angle 8e-ls*zifdrv nu5 l.q46 w7mbof 90$^{\circ}\,$ with respect to each other will not let any light through. Three polarized sheets, each rotated at an angle of 45$^{\circ}\,$ with respect to each other, will let some light through. What will happen to unpolarized light if you align four polarized sheets, each rotated at an angle of 30$^{\circ}\,$ with respect to the one in front of it?

What would be the color of the sky if the(q n i,b 5 +.d(anrceubkru8+n Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is, would suc-:j0f byg:h 5oygof ;nlight still be white, or o-: yb:o fg hf;5yc0jgwould it be some other color?

  Monochromatic light :rwuuc; :.hbw falling on two slits 0.016 mm apart produces the fifth-order fri;hwc wu :ubr:.nge at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 6l0w+j bri hp.31p jmszay7 /l,oxa06m10 nm light is observed at an angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two very narrow slits 0.048 mm apart. Successive mx+y1i o8ti7rrz3f ./oq2bwgfringes on a screen 5.00 m away are 6.5 cm apart near t23orfmiigxwq. roby8 z+t/ 71he center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-N; yf9;cepql ble- 2/y)i7zwl8qsc t/ce laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern on a scr7c8;l9)cc tie blzy //qwlfe ;ys p-2qeen 3.6 m away?    cm

  Light of wavelength 680 nm falls ecwp11pf 57yhh va ,,won two slits and produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is thewyf15h 7chv,a1p,e wp separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, how far apl/4p+zx qkhb,art are the secpx k4,hz+ql /bond-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found the 2w uwj)j:oqi.+ gqe1at blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at the same locatio:o)qeuj 2qgwe1 i.wj+n?    nm

Water waves having p+2iy-nl5jo, yfilm)jo j- o; yarallel crests 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, ayojj+j;) y 2i,lly o moi-n-f5t what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the zn); wg);ab f*gog,:x6i gqqslower slit in Fig. 24–7 so that the two waves6 a,)gq )bin *zqw;gg gxof:;s enter the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the third-order max:eh ; neok4;dwimum for light of wavelength 500 nm is located 12 mm from ;dw4ho:nek e ;the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by xeuh,nuu, qqz* f*,-hci42i /c4e cny544 nm light. Find the distance between adjacent bright c qeu, 4-cex4 n,fn2h i*qcuhz,u*iy/fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in ai1i*y or+1fd(invz(k am5fc 1yr falls on two slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a double-slit apparatu1x cyf6 rizj5:s illuminated by 640-nm light. The center point on the screen, instead of cfij6z5x1y: r being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the spftg v jx,*xj-*eed of red light (700 nm) exceed that of violet light (400 nm) in-tj,jxvf*xg * silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece eq5(l 0 d2 zqzob2sw.gga)sg3 of glass at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light containing tz /9pqj6 ofm3r-5stm a6a ;2) asmaiucwo wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on p 1fu9lo;xdu8a slit 0.0440 mm wide, what is the full angular width of the central d81pd; fulox9uiffraction peak?    $^{\circ}\,$

  Monochromatic light falls on 4p)gu2wi u/il a slit that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength en/pyk e+ff6(520 nm falls on a slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide is illuminated bw fi1 eputu2ok*90;m,e h9wg zy 450-nm light. What is the width of the central maximum (in cm) in the diffraction pa*0m u wok;e ugiz wf1et9h2p,9ttern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm mz5m7y )eii.nfalls on a slit. If the angle between the first bright fringes on either side of ti5mm7inze.y) he central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 j4;b ,ylb5qq fm behind a 0.0348-mm-wide slit i5qlb4, q;j yfblluminated by 589-nm light?    cm

  When blue light of waveru 90wzs /,l-g lufe8glength 440 nm falls on a single slit, the first dark bands on either side of center are separated by8 0g lwgus/ru-flz ,e9 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a hz-3coo ohdhrq, -t164pt8cihh4b 8msingle slit, it creates a central diffraction peak that is 9.20 cm wide onthzhhp 4o8co, dtb8i4r cm o-1q 36-hh a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the dif+raz ev 6-x5-fx kad6jfraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffra+6ef-a ajdr-5zkxv 6xction maximum for light of wavelength 420 nm?    cm

For a given wavelengthwtkdtj6tgr:9a 2 *0il $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produ m+quk--;orc kce a second-order maximum when falling on a grating uk--rkc m;+qowhose slits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a )w0qoi9a hot20enr (ygrating have if the third-order occurs at an 10noq2 (rhwi)otay 90e8.0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

  A grating has $8300\;lines/cm$. How many complete spectral orders can be seen (400 nm to 700 nm) when it is illuminated by white light?   

  The first-order line of 589-nm light falling on a diffraction 3q5 5:ylhvdsu grating is observed ath yl3:dv 5qs5u a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating*vglal)eu54 pq;p kb2(wm bv- has $ 6.0\times10^{ 5}\;lines/m$. Find the angular spread in the second-order spectrum between red light of wavelength $ 7.0\times10^{-7 }\;m$ and blue light of wavelength $ 4.5\times10^{-7 }\;m$.    $^{\circ}\,$

  Light falling normallt 2c8y 0gfwv688ptxf py on a $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order t)xr256 b/ usu)gt gcdwhat can be seen if a grating with 6000 lines pur5s w u)g/x2c)dbgt6er cm is illuminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can brf75xr w1 aiwh* c:sd,*o2wvw rpm6lsd36 ;mte seen on either side of the central maximum when white light is sent through a diffracw rfwitm1p arc hx*2dw drmw,7;636s s:o*vl5tion grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to , :/mj7s:n0 lnzabpj nzo1(za750 nm falls on a grating with jo nz7a 1lnpazsb:n: (mj /0z,$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light of a kno kbbd.tkby6tx(0d1 -5i 9qtwswn wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum lines are measured b- d7u,sc0de ryy a $9500-line/cm$ spectroscope at angles, on each side of center, of +26$^{\circ}\,$ 38$^\prime$,+41$^{\circ}\,$ 08$^\prime$ and -26$^{\circ}\,$48$^\prime$,-41$^{\circ}\,$ 19$^\prime$. What are the wavelengths?
$\lambda_{26.72^{\circ}}\;=\;$    nm
$\lambda_{41.23^{\circ}}\;=\;$    nm

  If a soap bubble is 120 nm thick, what wavelength is most strongly reflecj )uebs g8.i tnl2.(f6gxwn m1ted at the center of the outer susfb. 16u .ln(ewnm i jt8)gx2grface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if tut+dig q-/k4u.me ( cahe glass plates are each .-mq(gdk ae/u4iuct+ 26.5 cm long?    cm

  What is the smallest th4.f *6 2kxzwl0curlkeickness of a soap film $(n\;=\;1.42)$ that would appear black if illuminated with 480-nm light? Assume there is air on both sides of the soap film. $t_min$    nm

  A lens appears greenish u g /x7kio 412tlrs3phyellow ($\lambda\;=\;570\;mm$ is strongest) when white light reflects from it. What minimum thickness of coating $(n=1.25)$ do you think is used on such a glass $(n=1.52)$ lens, and why? $t_{min}$    nm

  A total of 31 bright and 31 dark Newton’s rings (not counting the dark sbk7acy ) zizc4 c;.w*qo8 u5fxpot at the center) are observed whecb 4 8)fix waq5c.ozy*;czu7kn 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optical7fwc2oorf3udd8 k c:5 ly flat glass, as in Fig. 24–33. When light of waveleng 2cd ow8o3rkf fc:5d7uth 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass surfacpp:/ori c im;6 wrqa/ ;gucy/(es if the glass is to appear brur:(r//a im6yog;pcpi/;qwc ight when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspecte sf2f--*r6)z ermtnsdgf,b 9ad of being a stolen diamond $(n=2.42)$ is submerged in oil of refractive index 1.43 and illuminated by unpolarized light. It is found that the reflected light is completely polarized at an angle of 59$^{\circ}\,$. Is it diamond? ----待选择----yesno 

  A thin film of alcoh.xxxpf ix y.h t2kgt6yiw3f.m1(q0z9 ol $(n=1.36)$ lies on a flat glass plate $(n=1.51)$. When monochromatic light, whose wavelength can be changed, is incident normally, the reflected light is a minimum for $\lambda\;=\;512\;nm$ and a maximum for $\lambda\;=\;640\;nm$ What is the minimum thickness of the film?    nm

  When a Newton’s ring apparatus (Fig. 24–31) is immersed in a liquid, the diamet klmj8.7xu7dbfh -:a7 y nd4seer of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive m7l.knad8:sde huy4 j77 f-xbindex of the liquid?   

  What is the wavelength of the light entering an inter* zn*qeh7+qlh o3z 89r-ys nokdibt9,ferometer if 644 bright fringes are counte3r qh8yz z7*k,b+q -ni9*edotsnho9l d when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movad8(,ctdx-l -3g azzh dble mirror of an interferometer. When the micrometer is tightenedzd -8dgd xtah (l-,3zc down on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mir0s5c0ry jd( 2zh)s/6qj eij n(q 5xgsaror $M_1$ in a Michelson interferometer be moved if 850 fringes of 589-nm light are to pass by a reference line?    mm

  One of the beams of an interferometer (Fig. 24–59) passes through a small glf 3)oc m-op-e7qltkmf 8( g6vqass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Cao-mpcgv3-oe8flk tq6 7 ()qmflculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientre 9aiy+k n30oed at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–58ss t2 qag/ hg+r+owm7b,bh vglass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water i -mloe/ ibl-g,9j b*i7 y)xtrlf the light is hitting the dob-)mjt i , *l-/g97brllxeyiiamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the ligf:in1:.iu3u pff r0kpht passing through them is a maximum. At what angle should one of trup.1 :k if f:uf0i3nphem be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed son 1 /*2;aiani/uo gbt*q4rphy as to reduce the intensity /ht2p* ao;gyn1 biui4 a *rqn/of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orilcs j0e+v hv9sdict h 4./21qwented at 40$^{\circ}\,$ to each other and plane-polarized light is incident on them. If only 15% of the light gets through both of them, what was the initial polarization direction of the incident light?    $^{\circ}\,$

  Two polarizers are oriented hwbfzh niow.,q3ty-h s-45f fk:/f *gat 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off the surface of water frglvj; )uih24or light coming from beneath the surfac j)2 4huigr;vle? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface.
If the light is coming from water to air, $\theta_{p}$    $^{\circ}\,$For the refraction at the critical angle from water to air $\theta_c$   $^{\circ}$ If the light is coming from air to water $\theta_p'$   $^{\circ}$

  Unpolarized light passes through five successive Polaroid sheets, ea55/ 0h/:scl1e iaa* dznb iwl6dy5dctch of whose axis makes addc6iczl5:y* db5w /a0 ih/l a1st en5 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength cl1ijcqokl-. 8jm1klw9n +i- nw 2w-o$ 5.0\times10^{7 }\;m$ passes through two parallel slits and falls on a screen 4.0 m away. Adjacent bright bands of the interference pattern are 2.0 cm apart.
(a) Find the distance between the slits.    mm
(b) The same two slits are next illuminated by light of a different wavelength, and the fifth-order minimum for this light occurs at the same point on the screen as the fourth-order minimum for the previous light. What is the wavelength of the second source of light? $\lambda_2$    $ \times10^{-7 }\;m$

  Television and radio waves reflecting from mountaih fjz gz-q odo-d ;/u8-7w7znens or airplanes can interfere with the direct signal do8hg;jqed-ouf/7 z- w7 -zzn from the station.
(a) What kind of interference will occur when 75-MHz television signals arrive at a receiver directly from a distant station, and are reflected from a nearby airplane 118 m directly above the receiver? Assume $\frac{1}{2}\;\lambda$ change in phase of the signal upon reflection.  ----待选择----constructivedestructive 
(b) What kind of interference will occur if the plane is 22 m closer to the receiver?  ----待选择----constructivedestructive 

  Red light from three separate sources passes through a dic,7ba g36bqa;x)ej6 8lsk tliffraction grating with e ,ta )icga8k;67jlslb 3bq 6x$ 3.00\times10^{5 }\;lines/m.$ The wavelengths of the three lines are $ 6.56\times10^{-7 }\;m$ (hydrogen), $ 6.50\times10^{ -7}\;m$ (neon), and $6.97 \times10^{ -7}\;m$ (argon). Calculate the angles for the first-order diffraction lines of each of these sources. $\theta_{h}$    $^{\circ}\,$ $\theta_{n}$    $^{\circ}\,$ $\theta_{a}$    $^{\circ}\,$

  Light of wavelength 590 nm passes through two narrow slits 0.60c2 ksk 0r+*9 duf4crla mm apart. The screen is 1.70 m awa 0c+rds k2rla49 uckf*y. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102vb w8 au4.tsvfd34eo..1 MHz broadcasts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance de3u.v 4t fw8odb4.sva, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back from an outside dqj,*;3ian8sgrp mtd/ oorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clg /p sqm3aji*;,rdtn8 early on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls oyv y-p50s*c wfn a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle f;p0 dfn e5ds:ese9 o*have a series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appea0sf5d fp:*n9seee ;do rs bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is to be no second-ok,k/).y pgapli dpg .a*9i cpz x0t:3krder spectrum for any visible wavelengthd ki0*) g. kppt gz3y.a9 k:,ic/pplax?   $ lines/cm$

Show that the second- and third-ordez p s0(mub, 2edzj0 ;nsm2ko0lr spectra of white light produced by a diffraction grating always overlap. What wavelengthsl2 ;mbz2eu0jnz po s0d,(k0sm overlap exactly?

  When yellow sodium l)bpmjx5dh 3 w(v jk7(pight, $\lambda\;=\;$ falls on a diffraction grating, its first-order peak on a screen 60.0 cm away falls 3.32 cm from the central peak. Another source produces a line 3.71 cm from the central peak. What is the wavelength of the new source? How many $lines/cm$ are on the grating?
   nm
  $ lines/cm$

  Light is incident on n;h.; s82ewa pde-v lka diffraction grating with and the pattern is viewed on a screen 2.5 m from the g8kh2n;;.evdlp waes-rating. The incident light beam consists of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clear material 1+,jwgpn 2z z 7/0qnzfyo.kxjif a minimum of 150 nm thickness of it, when laid on glaz ,jnw01ojzf pq.k 2 y+7/xgnzss, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident e+u)*cz3bms j normally on a thin sheet of plastic film in air. The reflected light is a su+3ce mb)zj*minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an anzsxy,iy s8.as fl kk1t4 (y0x3ti-reflective coating $(n=1.38)$ applied to a glass lens in order to eliminate
(a) blue (450 nm),    nm
(b) red (700 nm) reflections for light at normal incidence.    nm

  What is the minimum (non-zero) thickness for the air layer betw50d jb3t2 uitaeen two flat glass surfaces if the glass is to appear dark when 640-nm l5i 2 dattj03ubight is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the lh/)xznd4 ro- j5 q2eyqg 2zvx+ight transmitted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Coor -q4x 2ydjen +z2gzh) 5q/vxnsider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above 2 b8vm0-a*j1.a(r. igyg urh u d4vbxhthe horizon is the Sun when light reflecting off a smooth lake is pola (mxu.bi g-y8rh4avb.r2j1havg*ud 0 rized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so a3 9l*h iyeg4pxs to reduce the intensity of the incident unpolarized light by an additional factor (afte34 xy e*liph9gr the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whw ,/hrg jv.d.aose transmission axes are at right angles. A third polarizer is placed between the first two so that its axis makes adah/,w.gj . vr 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed iq;cq pf:l) 2 4w2fubvwn succession with their axes vertical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 17 -r/aqpo 0 .vk(in*(gd(acf bah-hyt:rdm)t .0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a H((qh i-r .ha/t:7* oy kbaa)cr0pd (vftn-dgme-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each placed-cqvh;wh p 6t3rn;)p 3rckbi+ at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap ;k a6b+v5abzmu kf;a 8$(n=1.34)$ coats a piece of flat glass $(n=1.52)$ .How thick is the film if it reflects 643-nm red light most strongly when illuminated normally by white light?    nm

  Consider two antennas radiatinru /p lwljja -tgz j9;2gtg rn*7w.:(rg 6.0-MHz radio waves in phase with each other. They are located at/plgj9w7 t;a jgjlrrn 2:-rw.ug(z* t points $S_1$ and $S_2$, separated by a distance $d\;=\;175m$, Fig. 24–61. What are the first three points on the y axis where there will be destructive interference? (Destructive interference in this case means that a radio receiver placed at that point would pick up no signal).    m    m    m

  A parallel beam of light containing two wlpn+*u75p0u5n eb 9 ,ha ifhvhavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral pris uve5,n l+95i puh*f0nabphh7m (Fig. 24–58).
(a) What is the angle between the two beams leaving the prism?    $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with    $^{\circ}\,$

  A Lucite planoconvex lens has one flat surface az16k2 tcch2,kpl lxcq du/ 98knd one with $R\;=\;18.4\,cm$ It is used to view an object, located 66.0 cm away from the lens, which is a mixture of red and yellow. The index of refraction of the Lucite is 1.5106 for red light and 1.5226 for yellow light. What are the locations of the red and yellow images formed by the lens? [Hint: See Section 23–10.]
$d_{i-red}$    cm
$d_{i-yellow}$    cm