Does Huygens’ principle atbx0,,8;-ggig1rc7 sfznhoa85up clpply to sound waves? To water waves? Explain.

What is the evidence that li) piq/jun j8e9s0rs4y ght is energy?

Why is light sometimes descrxe71gz ux3lye57 m*woibed as rays and sometimes as waves?

We can hear sounds around corner6 2fgtgcy7 ma(s, but we cannot see around corners; yet both sound and light are waves. E2 ga7ytgc(6m fxplain the difference.

If Young’s double-slvzk88 8+ ozv 7ov9m5ddm )pgeiit experiment were submerged in water, how would the fringe pattern be changed?d898v zo8kov 7im5+gpzm)de v

Monochromatic red light is incident on a double slit, and the interference o4 +t8h zikmx)w) hr7npattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue limx4 h8 o)iknz+r hwt)7ght source.

Two rays of light from the same source destructively interfere if their c cr e*yi+x3xe1-lc9pb go*.imp(w2qpath lengtgy* p (e c1q+c-me olwicb2r i9x3.px*hs differ by how much?

Why was the observation of the double-slwu*zy -sb*ee. l9nr6 uit interference pattern more convincing evidence for the wave theory of light than lb** sw ny ruz.-e9u6ethe observation of diffraction?

Compare a double-slit experiment for sound waves to that for lipd(4enj6z rlvz(fd*ns+j. -f ev*3rbght waves. Discuss the similarejdejl v+3rd f 6bnz*p (-*ns v(f.z4rities and differences.

Why doesn’t the light from the two headlights of a distant car / 3ndv bz/s iyqg81sv(produce an interferenz3gib s1/8(qnyvdsv/ce pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is co:oajv.mh 5,6-juuusu vered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the scr u:v6u . ohjmj-,su5uaeen.

When white light passes through a flat piece of wc ; pi.he/7hlwk*qg :seo 9(bwindow glass, it is not broken down into co/whw*b ek.: e(;qgoh97 ilcsplors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the foca usoyj9 gcpow.*df-*+l length for red light differs from that for violet d*-9*sp yjocu.+wfgo light.

A ray of light is refv9u vffa+rrk. 5;dzl(racted through three different materials (Fig. 24–55). Rank the materials according to zl dr v;.9u( rffvak5+their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distzs +c-(m7;m1 xnjrtnw dkp(h(y o,. fmant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.)d(w.nmty,mk+(c;rn o(m sfj7hz- p x1 Describe the pattern that you see.

What happens to the diffraction pattern ll7te5u q* .c6auz pf/of a single slit if the whole apparatus is immersed in (a) water, (b) a vacuum, instea5lp uuaezc6f/7 *q.lt d of in air.

For diffraction by a ; pceqfq3o;u90p w( dhsingle slit, what is the effect of increasing (a) the slit wpqe ;c(q0w;9of3h pudidth, and (b) the wavelength?

What is the difference in the interference patterns formed (a) by mghn4k :.w8 w l;9tdpptwo slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what imh*xt z8g1h /ys the advantage of (a) many slits, (b) closely spay/th8g*z x 1hmced slits?

White light strikes (a) a diffraction grating, and (b) a prism. A rainbow appc +kg3fcs-- fuears on a wall just below the direction of the horizontal incident beam in each cask-gcf-+fucs 3e. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incident normahshsw t wjhup)*r1x5vng7 0:f3 xuy6 )lly on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer de5ujx)gt vf3y0sxu7 hh)w6p1 swnr *h:pend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a soasw1fzs(p) :bvfl 3k .ims .5wlp bubble and not for a thick piece of glass,(.wsml lff )iv:3bps.kz1 5ws say?

When a compact disk (CD) is held at an angle in white light, the ref1 bf ksy0gfgcbw-wgp c*h70 .0lected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was u gg0pw fkbw7bg1fcy0-s*hc0.sed?

Why are Newton’s rings (Fig. 240yr8hl.*cshm2ut726b ux j ii –31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen bdxy /xc( zpi-5aufo2pn/id ;+y reflected light. What wavelengths do you suppose tz /ioy +u/fipd5-d;2x(cnx pa he coating is designed to transmit completely?

A drop of oil on a pond zsg blmpob+a-m0qg88kmpz 0y4 877 vd appears bright at its edges, where its thickness is much less than d7 gm z8av4 +l7yomq8 -zp0s8mkbbg p0the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the nature of ligh2(qc /.6pk msm s.vwfpt?

Explain the advantage of polarized sunglasses over normal tinted sunglasses.zowb9k- vz-di de vw7;rdi5)*

How can you tell if a pair of sunglasses is polarizing oa yny*(. fb2ep5.)i5x. sjrev)wh kx xr not?

Two polarized sheets ro ux,9e0 q swtxm2li6w4tated at an angle of 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 Earthd21sgb+lxuta uy0xlf i jo,+ ,09jn8g had no atmosphere?

If the Earth’s atmosphere wekth3z* x ev(-ore 50 times denser than it is, would sunlight still be white, *zx( k tvhe-o3or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produce3tfoba2*-rcwth2 oew+v *c 0e s the fifth-order fringe at 0ew+3bw-h**tv f2caoor2c t ean 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm :62r v:y) z bfenz8doz )czx4mlight 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 slit:ho lylfx2g5) duy:l1 s 0.048 mm apart. Successive fringes on ayol:l):y2uh1 lx 5fg d screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavblx/ yx;gi6h4h t92jq elength 656 nm, falls on two very narrow slits 0.060 mm apart. Ho hq6itlbxg yh;9/xj 42w far apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nmz0gy(vx 9(y.jcdo5h ; ; /vm ydx+dymz falls on two slits and produces an interference pattern in which the fourth-order fringe is 38 mm y oh;5dgz. d/9v0c+mdxy(jxy(;m vyzfrom the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes throu9 x k+:ebe-pbzf6 tm1zgh two slits 0.58 mm apart, how far apart are the second-order fringes for these two w-xkb 6z +pmz t:efe19bavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it iuk;6ltaw ;s 1fm- nc/ks found that blue light of wavelength 460 nm gives a second-order maximum at a certain loc f/ makl6k tus-c;w;n1ation on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pasxz; tlwn, xbfv* *r+1,qzfiq5 s through two openings 5.0 cm apart in a boarx nxq1f+*q; tri,5b*z,zl f vwd. At a point 2.0 m beyond the board, at what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is place a:isr)p.z-o dd in front of the lower slit in Fig. 24–7 so that the two waves enter th:rd ao)i-p. zse 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 maximum for light of wavelength l7:hd.mrla nj 01i*vj500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then1rv: *i07d.mjalj hln 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 illu6n0y az(h qye6minated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 yq n0h66z eya(m from the slits.    mm

  Light of wavelength 480 nm in air falls on twsxq hjot.8hl( tcy,iu0 6s+3zo 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 a* i wzyb/nell zk,(a):ey7/d.60) covers one slit of a double-slit apparatus illuminated by7(, y*)l lz// awb:dizeay ekn 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed thaij6i no.d jr.d(e wj-)t of violet light (400 nm) in silicat)d dj6o. eji. ni-rjw(e flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at:1n x hdo+4+ jyz2qwba 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 contaiet8jzi4co z p* ojwx ku53*/q+k d+(ozning two 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 fall*flmj uyud*)+z0 eogp y,b 1ezwt ;-+js on a slit 0.0440 mm wide, what is the full angular width of the central diffraction peak?lj0z um* fg*uje+e1y doy zp ,t)w+-b;    $^{\circ}\,$

  Monochromatic light falls on a slit ta2ip 5jgz,-o)e (*fgtj e,p (ox .ibschat 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 520 nm f9bzvpb qqyd7 9y+f)fcc 0 hu ,iruv p301ro:*palls 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 by 450-nm light. What is the width of t(m6m1ua:n g: gci 8dpihe central maximum (in cm) ingdng8pc i:6 1ai:mu(m the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the ang6cmx7( :ick,q5ywhj kle between the first bright f,7yci 5k6(xjmq:hwc kringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the centralq 4isi5wutk( r1r 0.5aqiwlx4 diffraction peak on a screen 2.30 m behind a 0.0348-mm-wide slit ill. 4 l0wtarsik5 qiwx(51r4u qiuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single sli0d s -zi7)d*pzh1g hgjt, the first dark bands on either side of centers0 h*gz- z71ghdjipd) are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm f3qukn/c 5mm- 6wqfn4 falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the sli f/fc- 6umn3m4 5qnqkwt?    mm

  If a slit diffracts 650-nm sdi.6. dbe8xalight so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for.bs x8ei6dd.a light of wavelength 420 nm?    cm

For a given wavelength (.*zueezzc7sw;90j3 j gieb: rtbe3o$\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light prodn5zefdm r-dbrp5ra67,g 98y ruce a second-order maximum when falling on a gratigb7 9ry zddrf6,mp5 ren5ra8-ng whose 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 du2gl8,ur mkv*zs ph4x1t) n r4oes a grating have if the third-order occurs at aumrn1rp 4)tu4k,g x2z8 l*vshn 18.0$^{\circ}\,$ 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 grating cc2pwyceeh 20 .hvn13is observed ave cnph0h.e 1y32 w2cct a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingpt /*s1oe8;jw u.hycn 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 normallin5t gf5xr -7rru l);sy 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 that can be seen if a grating witov )os.jn/ -pln /n7vkh 6000 lines per cm is illumvo/) nks nj/. nv7o-plinated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can.dm*a/kb;6abc62 .qyq bn kgm be seen on either side of the central maximum when white light is sent through abk qnkcbd6y ba*m2/; mq.g.6a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengthphkt h2l7amdb -l:b ./s from 410 nm to 750 nm falls on a grating withh/ab:mhdl k t2. -b7pl $8500\;lines/cm$ 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 kno4 gbq )ee;hd;s1cqq6 ewn 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 meac0ln ww;x)swp7 i8vg6sured by 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 12,v3 /wys cvvq70 nm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by wvc3q/wyvv, s7 hite light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if th /3vq-8yyd of9ujwsi )e glass plates are each 26.5 cm8 so jyfd3 -)9qivwu/y long?    cm

  What is the smallest thickness of a/cqk5e b)-/ csqog4zb;i8g za 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.krld rtln59a6l4 zs+ yellow ($\lambda\;=\;570\;mm$ 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 spot al.icjmy j /r/5t the center) are observed wh r/i/. cjjyml5en 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 op9tt 2,3qwwfnetically flat glass, as in Fig. 24–33. When light of wavelengwq 3 e,f2twtn9th 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 airvql 2i/1 9pd4hw;: ftauh5t zo layer be between two flat glass surfaces if the gu1ih;f 5/p oq92vl wtdaz h4:tlass is to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stole .htc 6m-v/ezen 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 alcoh5hyd;1xfh9b z-c m4l aol $(n=1.36)$ 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, tanz6hfmvzf(l) g 8u a1sfd/3 c6;ezr-he diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive in /(nsuf)z 38zfdeg a1-lrczm 6;hva6fdex of the liquid?   

  What is the wavelength ofrtf nb4 i*(t9g the light entering an interferometer if 644 bright fringes are counted when the movable mirror moves tn g(b9t4*i fr0.225 mm?    nm

  A micrometer is connected to ,mg25h scv6yf/ -v4g8f snqfxthe movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the x/4gf svs,mf q6gn f2 8yh-v5cnet 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 mirror bup(+,g 0sjqr$M_1$ 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 (Fik92 1tiq9tznp9w a0o. ubc) ggg. 24–59) passes through a small glass c9 ku)wq t c9an2o90t1gizpb .gontainer 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. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 6 z.(pw8+ih8p )zn udvd5$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an nsy+66 axxvd/b/wd:li 5:*y o4 gdgkcair–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s ans4y -yjfr-rs(gle for a diamond submerged in water if the light is hitting th(yfr4rss y-j-e diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them3z v bw9x2)rtn is a maximum. At what angle should one ofr )nvx 32bwtz9 them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plackvof5f.i 1sd ;y*e 6hled so as to reduce the intensity of the incident unpol;*fy1o 5vied hlsf .6karized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are or* vk m5uumrgk -v)w1am++ cu7xiented 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 oriqxgs8g - 7cvi+rfn((x ented at 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’s7t6+hes( bo tt angle be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal refltot+s7( h6ebt ection, 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, )rhu: j-qzl bv2v8t ylax-t 6uf:e59ceach of whose axis -8xc-)z6fvlyea ttb2 5uhv :r 9:lqujmakes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength r wt/.,p4eloe)o ci9o$ 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 rbo*b+d ,y4xzgk+ y + l:kizi)meflecting from mountains or airplanes can interfere with the direct signal from o:lgkym ++ kd)+ybi 4z,ixb*z 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 diffraction grating w)0ie 7eoll-7ho 7eztiwy.w(a ith e)l loe 7hay-7i(t0w izow7e.$ 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 nat1tfr+2q4z l;.l,j uq5k 9)vtliltwvrrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the cent krtl9ql),ftl;4 v .i+5juz2vltw 1 tqral maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two identical antennaelrbri;q y2z. t :xkv:,w1p5vd5)dx ox at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found alonxzo,v:vrqp ly t x.b1w )5r:dxd ;52kig 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 doorway 0.88 m wide, and blows fz2qv. o b7.aq bxmn,+mj4 ;zta:fw2oa whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground outs;qn .b+z4.,t:2wa fjqxmm2o ba7o zvfide the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit9+8p hphu nli: of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series 2hx( p qq .l+hn))tukw pf3g3oof parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an a)( qgfopt3k l.nhqh+pxw)3u2 ngle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter mu0 b o ,wwow+nzi1cu.5ast a grating have if there is to be no second-order spectrum foraw1b5wci,o0 +o. unw z any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra oen.qw fbh4n:( f white light produced by a diffraction gratn:h4n.fe(q wb ing always overlap. What wavelengths overlap exactly?

  When yellow sodium lijo6e:6lv rho- ght, $\lambda\;=\;$ 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 a dipz dg-vf a6a+ r,w1ui/k.hup+ffraction grating with and the pattern is viewed on a screen 2.5 m fug-.d1ru6hfk ,/wp +p + aavizrom the grating. 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 refrr2hiev yy+j) 0action of a clear material if a minimum of 150 nm thickness of it, whyy)e2rjh+v i0en laid on glass, 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 incidenyr*64 xri2v:pep *wsqt normally on a thin sheet of plasti *ipqwx4 ery6p:2v*s rc film in air. The reflected light is a 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 nex.6rdxpdi3 y,on lg)3 eded for an anti-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 8 vbl8- o;+rxftaex4)n mdax,dpn4s+zqgt0 3for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm light isbp8 4; xsa4+mz rdq3)td a-0xox tng8+e,flvn incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted thro3qtjv ke aqew.2(6b(ough 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. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero3 ej o(evq2kw.q6a(b t.
24-30
24-36

  At what angle above the hosf ydsntq;3z*. lc2 k(rizon is the Sun when light reflecting off a smooth lake is polarized mosstf(3 *ykl . 2qzcnd;st strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so , ;4q;* tonkmrugl ,ipxh5+tux;jq b5as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts u +l5 x ,;;,tgj5q*b tqurm k4hp;oxinit in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarq f pg/xbl+( i(6luao3izer sheets whose transmission axes are at right angles. A third polarizer i6oxu +g(pqbill a /3f(s placed between the first two so that its axis makes a 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 in succession with their axes vertical, at+c, lr3 p+rkmnneor/h j8j0o9 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 hbk9s-xw3 q+g slit of width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assu+9 qs bxhwkg3-me the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are m9ztp,+ phtv1each placed 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 g s:d;4x+dd -*ewfrnd$(n=1.34)$ 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 radiating 6.0-MHz rr69/ rv6/vbbd ha9p pladio waves in phase with each other. They are located at pointahbpv 6r/6vp /9db9rl s $S_1$ 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 wavelengths, 420 nm and 650 n*u )5 *+cf;yratf vl*ffyifk/m, enters a silicate flint gla+ / *; yf5ff*itayv*)f krflucss equilateral prism (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 and oneazjwe ima.ppu 0/5 n.* 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