Does Huygens’ principle apply to sound waves? To water wlwp; z6g20sna8dw/ a waves? Explain.

What is the evidence that light rlf7d5sco - k6ow0ws:is energy?

Why is light sometimes d3 5y+fw9 hyg:1 9 wqut16xz-zbwkfm ueescribed as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see aroundeu;b 8yw s6bmzt t..8 pgp:u6m corners; yet both sound and ligh.t m;t6.s wu ub8z6ybp:g m8pet are waves. Explain the difference.

If Young’s double-slit e9,zws+bs pfq )m0 luc4xperiment were submerged in water, how would the fringe pa c +)qpsf9sub,zm0w4l ttern be changed?

Monochromatic red light w*j1m 1f7ev-u/ t jgkois incident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is repla*k1u7 1eg-vwo/jj tfmced by a blue light source.

Two rays of light from the same source destrwtm:w2 ae xo/9l1+sdv lw4mdr8 fz*:x uctively interfere if their path lengthsadot/1lw9+ x8: w 4:l2me m*dfxrzwvs differ by how much?

Why was the observation of the double-slit interference 0 n)p.expz e7 oqzb 7f*((itpdpattern more convincing evidence for the w7pfotb.(z0p n (ezp iqxe)*7 dave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound wa.zwa z99dwxt47 vpa5e ves to that for light waves. Discuss the similarities and differencex .wvzw9p4d aetz5 a97s.

Why doesn’t the light from the two headlights of a distant car ppmm83ntgyvw0i9jf t3 ,fj; .xroduce an interference patxvf3 ;.j 3fi mptg,9m8jwy0nttern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is covered4/ o )gcr6munzhm*ph) by a red filter (700 nm) anopm)c6u4mgz * )nr hh/d the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of windowo, gw 4fmamtuq9xf0j:v 4,-ch glass, it is not broken down into colors as it is by a praouw40h mtq,g:j v94fcfm -x ,ism. Explain.

For both converging and diverging lenses, discuss how the focal length for red lfj(t zo nx5tu6e 9gz4*ight diefo*jtztz(g9x5 6n u4 ffers from that for violet light.

A ray of light is refracted throug+ m0u5ujgsqo3 h three different materials (Fig. 24–55). Rank the0+ 5 jmqgsuou3 materials according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant 1qw2i( 0z nny:m9pnn hlight source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Des (zn :10iq2 wnynnp9mhcribe the pattern that you see.

What happens to the diffraction pattern of a sinrt32ate n)f .uxdd;2 txnum9(+ mvma(gle slit if the whole apparatus is immersed in (a) u.9a ex)2m 3+mr mxfdt t(vt2 ;uandn(water, (b) a vacuum, instead of in air.

For diffraction by a singli q9u9g07wen ,ph ks.ve slit, what is the effect of increasing (a) the slit width, and (b) the wau sg07w. ihnvek9qp,9velength?

What is the difference in the interference patterns formed (a) by twosty pwnv 9ea)i(o 43q) slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the a cjvrj-0kgq 8o uiv*/:dvantage of (a) many slits, (b) closely spaced :*qki8rjovjg0v/c u-slits?

White light strikes (a) a diffraction grating, abz5.xakht-,tbt ;b8 hy(k( g1z ryy0c nd (b) a prism. A rainbow appears on a wall just below the direction of the horizonta8 kb-cb(5,ttza kzhyg . (x1 h;yb0tyrl incident beam in each case. What is the color of the top of the rainbow in each case? Explain.

For light consisting o j1 du:frk93czf wavelengths between 400 nm and 700 nm, incident normally on a diffractionz 9r ufdk3j:1c grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for ra65fa0 mfn( ba thin film like a soap bubble and not for a thick pnfa05b (rmaf6 iece of glass, say?

When a compact disk (CD) is q)w+j; yozlb1zf/ z1 vgp,n 8qheld at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to sefb118 +gzjqnzy;lvw )p q/oz ,e if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther fwa ji p;ru;qr e0cct *jx4;(p(rom the center?

Some coated lenses appear grqpity06ir(i uku4m( 4eenish yellow when seen by reflected light. What wavelentq0mr(ypiu6(i u i4 k4gths do you suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness is mu2dy nsoo f8sky;8e -z;ch less than kod;yf8esz8 n;oys -2 the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the naty j5u/b0ox x,kure of light?

Explain the advantage of polarized sunglasses over normal tinkrqqi;s7 ,z(gpow0n 0ted sunglasses.

How can you tell if a pair of sunglasses is polarizing or jp3ki +zymcnqtu v-ll7,2 0y:bwg :8 xnot?

Two polarized sheets rotated atqi 4c q/p6tm0nw5mqtst:51q 3mk6 jyt 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 t3cb222 fayrzb7(ek xdhe sky if the Earth had no atmosphere?

If the Earth’s atmospherel*/m zh8.+x7b zg zohc were 50 times denser than it is, would sunlight still be white, 7/ z+.z zbxl hmco*8hgor would it be some other color?

  Monochromatic light falling on two swsn(h t 5rf4 b+6ezm/nlits 0.016 mm apart produces the fifth-orderrms4( w/nfz6n b5ht+e fringe at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at an angle omeds8u3q6 kv d;, 5x*r*hwxa;e ( vlimf 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on biimq7n0w3i 4les f2zns2;1t two very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away a b 0 ln1iqz3 7sm2wn4tfiei2s;re 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 fuck4, /mk34 wfru.hszrom a He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apar/4,kr34fhmuk.c u swz t. How far apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm roq/ u7eurc1(falls on two slits and produces an interference pattern in which the fourth-or1(r7uor/u ce qder fringe is 38 mm from 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 ta7duvb gyoly3r/y y ee9n*fn37d q.4 9hrough two slits 0.58 mm apart, how far apart are the second-order fringes fob77g9fy4yq/ .e3an* udr9 vldy 3oyner these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 lufne3k) knx ,rufh,e-3 5z/cnm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at -xnnfe 5e3lk chf/3z) ,kuur, the same location?    nm

Water waves having parallh82o5 t jz/+ /vjdkxm3x1cu2i-nujq pel 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, at what angle relative to the “stv+zxj1u o3j/2tm/hn8uxj 52ck p-iqdraight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower slit6ujv mgz*o,;1comc6 q in Fig. 24–7 so that the two waves enter the,j;*oz 6gc uq6c1om mv 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 experimen;s.:+ w 9t8hki vwkpfqt, the third-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the sli: hkt. 8wif+ psvq9k;wts. 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- wjbu+8/-znm bk,e)wnnox ho ( zw/u5 by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m fr5oxh/(-z ub/o ek8-wwbnjmnwz ,+) nu om the slits.    mm

  Light of wavelength 480 nm in air falls on two slifzyz ,hw9ko6cy c*9: lts $6.00 \times10^{-2 }\;mm$ 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 ap5g, 4se2b p.g h(hvbmwparatus illuminated by 640-nm light. The center point on the screen, instead of being a mmbg(vpw5h 4b2hgs . e,aximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speev .u42,;d.zlcadbj. vf f*jmd d of red light (700 nm) exceed that of vivddumd;.z fvjl .cf* 2.b a,4jolet light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece 6,*a l0tgnwhw 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 lighthdi j* 1xm0y2 v6 ; aupvtjv5n)xu0(jt containing 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 falls on a slit 0.04cf j-/ cnbtfh7w a64t;40 mm wide, what is the full angular width of the central diffraction peak?b7ja; h -tfc/fw tc4n6    $^{\circ}\,$

  Monochromatic light falls on a slit that ie4iwx, x6*nfq6n)c +i 6dkqlis $ 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 falls on a slbh2*:o nuhpm)/x8b unit 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. W 9;.w( lccv(pr aw))papdho ,b7g ao;chat is the width of the central maximum (in cm) in the diffraction pattern on a obg7 ca,w .r9 ppal wo;vp(acc;d)h()screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the a8omb2o+ 67jirede*cl ngle between the fir mcl+i d*bere8o2oj76st bright fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction pea:. u / znzs9ea14ba6z9m t) iloz2pnd cci9)fok on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm ligt6.n:d s9fbnoz/lpz9 az42i cc)iz1 a) emuo9 ht?    cm

  When blue light of wav + laxdqb*0zm8-erv9yelength 440 nm falls on a single slit, the first dark bands on either side of center are s9x q0b +8lvym-a *erzdeparated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single sl0g8rah-umvj* ayxhgd/cf 8+6it, it creates a central diffraction peak that8v/-uag6rdx fj*8yhm+0 hcg a is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction4zey1;ib7 uue ao n20k)o )hpn maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light of1opu)k2y47uano)b ehz 0 ei ;n wavelength 420 nm?    cm

For a given wavelengtpl i wchaefy-; q9p6av(0 1ag+h $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-order maximum when falveuocbw -v52 -ling on a5 uow--v 2bvce grating 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 does a grating have if the third-order occurs at akbm 4ry3lgo4 *n 18.r4bl3 *ogkm 4y0$^{\circ}\,$ 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 gratin ye.bv c(xk9hkq t; (6el;orf7g is observed k9er;6fc 7v;x.( yq(tkoehlb at 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 h )pqrtk /f3 dpv;k+d*tas $ 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 normalltx9f8bl, )b8: vykfp ly 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 o9njx1k y 59 huraz9)3dedvp0xrder that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser l9pe13x j )0yax59zdu dv9rnhk ight? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen onn)lfb8ksp ,1qr i- be: either side of the central maximum when white light is sent through a diffraction grating. What is the fqrk8:,lpebn -)ib1 smaximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls od.94t (mia nqtn a grating with4 . a9(tmiqdnt $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic;e3y jxe (sr.s light of a known 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 spectrgrlx1h. heh.p-i.h r.*+od( zl4 auafum lines are measured 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 120 nm thick, what wavelength is most strongly/ 7rzdu9t3nk mcahns;q. g,e5s s d6q( reflected at the cehs7(z6/u e r5m9 adskqnq3c .n;gsdt,nter of the outer surface 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 the glass p/4/hnihas nz-g,yt + kbpg;g4lates are each 26bzh a4y+tnkgp n4 i/;ghg-s,/ .5 cm long?    cm

  What is the smallest a ab;0(i: 8o .eprulixthickness 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 fm ki4cjk u93;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’stm4o8rd2jmwoc +elvnvu h33xc 2 o6f*3 b 0pc0 rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is thcdv+ ho u2m4rmxc3 oj*3802nfto3bw plvec 60e center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces ofg0 cw*j,rv 0al optically flat glass, as in Fig. 24–33. When light of wavelength v0* gjrlwc 0,a670 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 t) ,: k/ebyxdxmwo flat glass surfaces if the glass is to appear bright when 450-nm light is inci) bkex/,m dyx:dent normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a sto 6ebzv):) p.qm 9nswonsz7ijh*9tmu:len 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 alcohol ek7 ym8f:r z5t$(n=1.36)$ 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 liquid3 mu*e xqor(6p9lz3anp o o01y, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. Wh1nqrylzepp0(o 3o*9 m x 6oua3at is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferomftk c ut1h;w 6q ;)e/n,zfe3xmeter if 644 bright fringes are counted when kh,e6 ztn/;;xftcmfq 1u3w) ethe movable mirror moves 0.225 mm?    nm

  A micrometer is conne :wp) wf)pow:hcted to the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty micromf)wop :wwh) :peter, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirrorvj yuuut2xx -*p09l ,nswpw 3( $M_1$ 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 ang3fpt xpp vza2b-0v4+ i 6kaq, interferometer (Fig. 24–59) passes through a small glass 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. Caz2p4, a v-+fx6gk pbq0pit3valculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriente z u6mr 17hv;g8yloa5wo8ru .w,eo/ tnd 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–glasslsv*+rqpe;t sl8p q .a) jd5j9j;k 5gx $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in watctm46 gm(lv7qza6xq g z1 41pier if the light is hitting theclv qg (zi16qmm4za 7g4p6t1x diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a /ljm)l /o3e6.ck6 s no .gbqnpw/5w bfmaximum. At what angle should one of them be placed so that the in56 e.p. kcogl/b63w)f obnlsj /nmq/w tensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the ixsq+t r. f7nu/ntens7ntsx fu rq+./ity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orientedymdgq .dr2d :. 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 at 380kph(:z nafn p4v jb j925gzj7wi;m. u.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 t ofpl7:7 f4aoof water for light c al7ootfp7f:4 oming from beneath the surface? 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 g/9ufq)rfxj 6 sheets, each of whose axfrx/ jufqg)9 6is makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength f-oeu 499p)gnqq; is n$ 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 mountains or airplanes can inzgo.3k p6g3ptterfere with the direct signzp33.pkg6to g al 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 snr07hktl+)6vfn xm. 9e x;bvneparate sources passes through a diffraction grating with f6xr7xblm; 9v+v. ht)n nenk0$ 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 s y6den6vs6 mgrx7zwer+k; 0 q0lits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-orderk7my+sg0 v6de;60r w nx6rq ez 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 102.1 MHz broadcasts from two identical a*h/o3w 5int: yk3hn vuntennae at the sy* w:hu otkv i3hn5n3/ame elevation but separated by an 8.0-m horizontal distance d, 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 wel/v vkw0i6psk ):w( bxll back from an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring refles ibwk( :6wvl)0/p kvxctions, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of 7bs l;o.f zp dqvz0;7+jrlw1f y/5wrcwidth D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain bexp,x,dgx 6 a9jetle have a series of parallel lines across them. When normally incident 460-nmg,xxxjd9p, 6a light is reflected from the wing, the wing appears 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 secg2t1tv;o)esl,f tn2rond-order spectrum for any visible wav1r)tvt, en g2fo2tls;elength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced 1zvwq76 u;eg8 wad2 gkby a diffraction grating alwk7u 2 a z68dv1gwwqe;gays overlap. What wavelengths overlap exactly?

  When yellow sodium lidc/s9zhbof7 :-lwp w 3ght, $\lambda\;=\;$ 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 diwr367q 13gwzmyw.g ppffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of two wav63m1r g.w7gywp3z pwq elengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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)l14xws)zh mq clear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to re) wz1q slx)mh4duce 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 norm,ejry6s(fw6xp dlh- 8 ally on a thin sheet of plastic film in ai6we6xdy,8 (hsp -fljrr. 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 needed fo1;m ;v eupa22evom (hcr 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-zeroz +.zn+eq;iuk ) thickness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm light iz.n uzq;e+ik+ s incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a t5t +yc kzs(3:tzxknv16 w+w-5yx5km a0cv yqshin 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 relatinss0kx65aw5x+ ytk cmv53-y: ywq tk+ v zz1c(ve size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflmlfc)swe psq0* q-w*9ecting off a smooth lake is polw-)*fmq 0wpq*9scl es arized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plack:myj drd-,dc a q161ved so as to reduce the int:d1k y,v rd6ajc- 1dqmensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose tra0u pw69i3fdumab7iv 3 nsmission axes are at right angles. A third polarizer is placed between the first two so that its axis i w96iu 7v3 f0md3uabpmakes 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 successionkhm 2vj4 si(r+v5 t8wr 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 1.0 cm and ihyck -0of)k(7(alfa/p9i (p yn2hfbns pointed at the Moon, which is approximately 380,000nyk-f a (h9f0(kc7/ p2i)bln(fhpayo km from the Earth. Assume 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 each placed at a ae0i j ,rpexsx71hohgvf ); -k+tk,h710$^{\circ}\,$ 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 zj9. .fj; qjpe$(n=1.34)$ 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 radio waves ir. so6 r7rx7cuqx8 g+zn phase with each other. They arqx7g+rs6u7.r8r zox ce located at 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 wavelengths, b 9ii.+1v1llean5 4thlobi8w420 nm and 650 nm, enters a silicate flint glass equilateral prism (Fig. 24–58). . vie4hi5i9n11bwoa ll+8tbl
(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 one wjy-n 32pp)hmk1b q5)(rf rcxwith $R\;=\;18.4\,cm$ 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