Does Huygens’ principle *afch .imzgisya* 2u -mst;:9 du0+wn apply to sound waves? To water waves? Explain.

What is the evidence that light is energy?zqa9ig* o+r z.

Why is light sometimes described as rays anz, s 6alx1uk;nd sometimes as waves?

We can hear sounds around corners, but nmu 2nfnt t,j d,hp/.5e6h i)jwe cannot see around corners; yet both sound and light are wa/. jhi,n) nttuf hm6n2,je5d pves. Explain the difference.

If Young’s double-slit experik-x7y; /y/nqs2g4jnnx c2mv nment were submerged in water, how would the fringe n -qn x/c/2xs274vmnyk; nyg jpattern be changed?

Monochromatic red light is incident on a doubledce8bne rj0dnv8+xf ds5u )x-f x/)i, slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would u -ic8v5n,b+xe /)d)fe8xnjx dsdr0f change if the red light source is replaced by a blue light source.

Two rays of light from the same source b)1: nchj5mufdestructively interfere if their path lengths differ by how c5u j) m1b:nhfmuch?

Why was the observation of the double-slit interferenuoq)*a ccmak 0 62xl mag.9mq,ce pattern more convincing aagakm 9).m*x, 0q 2ccqlmu6oevidence for the wave theory of light than the observation of diffraction?

Compare a double-slit experimj;ut/:sdw:* y ljx3 feent for sound waves to that for light waves. Discuss the similarities and d /*;::wxfsjjutdl3y eifferences.

Why doesn’t the light from thg db) *8iuo5cq +btmv. -rfy0ae two headlights of a distant car produce an interference patb8tb+0 v*- )mu fqra gi5cy.dotern?

Suppose white light falls on the two)avr 0tj3n(ta :rc0 lv slits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other b 0)jrl 0av:t r3at(vcny a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of g.uxx( -cu(6ncen oie2us4 kqa0*,bt window glass, it is not broken down into colors as it oku . eucinua(0x-b4c,*q xsg6n2(t e is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal lezuwp+/ m/ s/uhngth for red light differs from t sm+ zu/wup//hhat for violet light.

A ray of light is refracted through three different materials (Fig. 24–55).h ;o68z, hgi39 j1 mhfdkzkflk8b *x9h Rank the materials according to their index of refraction, least hhdk6x9h 89,3zlf8 * gfozb; jk1i kmhto greatest.

Hold one hand close to yx(a+)20go hz ax h)j06 ihvpzbour eye and focus on a distant light source through a narrow slit )zi axo+20(6jxbvh 0a) hphzgbetween two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single swu x,h:kbxwh4kr+1w;lit if the whole apparatus is immersed in (a) water, (w;u:4w,xwkhbk+ h1 rxb) a vacuum, instead of in air.

For diffraction by a single s38rg p0 9tnmumlit, what is the effect of increasing (a) the slit width, a m 0tgp8u3mr9nnd (b) the wavelength?

What is the difference in t-x9y1 ;xd uxxthe interference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (a) mapc3q rlj0,;sy i7 a+3t ;zqywpny slits, (b) closely l +rap;s0j z;3i,pq yq7 3wyctspaced slits?

White light strikes (a) a diffraction grating -*mef nd /a m(-/6nvzqatzfl+, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbowa nzf(/vf- t6lanmz q-m*e+/ d in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incw rjplklhb53no3 xs6 6/g+q:oident normally on a diffraction grating, for what orders (if any) would there be overlap in 5o3rwlb:osp 3 xkn6l6/jqh+ gthe observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes m,i6o:fsg n3) fugb f)ak.mp1noticeable only for a thin film like a soap bubble and not for a t:gbsu3 .6 i1)pf)gmak mfof,nhick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the 3/pcn+5mpvol reflected light is a full spectrum (Fig. 24–56). Explain. What woul/+ mnlo53cvppd you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fa,xt t/*mew b/jrther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. Whattkxn l9mq-g,ieh7 +zs ):k 3yl wavelengths do you suppose the ceynl7s-3i9x k+)gzk:t, l hmq oating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness ryna16b k:j:6lwv p0x b 7pk 6ci0nnp:is much less than the wavelengths of visible light. What can you say about the index pl:0k bwnr ca0in n7p 1k 6yvp:6b:6xjof refraction of the oil?

What does polarization tell us about the nature of light?*v s p,,y( stu-ddgr6c

Explain the advantage of polarized sunglasses over normat9(ex e.pios0 l tinted sunglasses.

How can you tell if a pairfos+t 4y;;xn u)xmgc2-ljpptxfb9f-// 2ln l of sunglasses is polarizing or not?

Two polarized sheets rotated at an angledxb 7hjn je9ce-)y gifl 5/urz1j: ;6g 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 Earth had no atmosphlu h 54x7.uq dp1j;r v/lmh4cyere?

If the Earth’s atmosphere were 50 times denser than it id 2lmvz ty/(-;bbr9.u y0bevjs, would sunlight still be white, or would it be 9/(b 2 vd.tuy0m-rybz e;bl vjsome other color?

  Monochromatic light falling on two suu ;qxk6/qspk3j 50oelits 0.016 mm apart produces the fifth-order fringe a u5 u0o3peqk6x/sk;jq t an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of+bhnm/hutt e *lbs,0 4 610 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 vu.yit d4zyn/*7 j(xy two very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency yj *vy.z 7tin/4(xudy of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light frouti64 lk7 duk5m a He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far aparuku 6d t7lk45it are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and gprxfm cndp(01(.;2j1 m pnvlproduces 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 the selmxjcf p 2n11vp.(rnmdg;( p0paration of the two slits?    mm

  If 720-nm and 660-nm light passes through two slitsaeaw31 sysx35 vg+m 4p 0.58 mm apart, how far apart are the second-order fringes for thesm1a33vw4ae5 gy pss +xe two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light op8dtsyy6gx, 9f wavelength 460 nm gives a second-order max8x9p d,ygt s6yimum at a certain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having paralleamnt 5 byr).hz2b41o/win 8d wl 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 angl zo.an)bd2/wr15y8ibh t4nmwe relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is pv ba*3l6 v*fi7o i2drulaced in front of the lower slit in Fig. 24–7 so that the two waves enva*3ir i2o* 6lfv7bud ter 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 maximuukm+km)d6a mv-e. ab3m for light of wavelength 500 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 then projectemu 3+mbek)-ka.6v madd 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 a1 14knxfl vbc(re illuminated by 544 nm light. Find the distance between adjacent bv1f(l nx14kbcright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air faqy l(3a ne:bk:hn/a r4lls 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-slqagnhr;pw ugb4 ,0r --qq; .nsit apparatus illuminated by 640-nm light. The center point on the screen, instead of bei-qq 0n ,p wrsuhg.n; ab4g;rq-ng 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) exce4q)2e+a bef.av pqa k/ed that of violet light (400 nm) in silicate flint glass? (See Fig. 24–)/p e+2afvq.ke bq4aa14.)    %

  A light beam strikes a piece of glass ad-lj*efx; c 8at 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 two waveleng2d 5ig*6wsi)kbwso sg0h:h*zths, $\lambda_1\;=\;450\;nm$ 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 0.0440 mm wide, wha(5e rd5 naqi6at is the full angular width of the central diffraction 5e5an(d6qri a peak?    $^{\circ}\,$

  Monochromatic light fallm2usn4nmwc r.f2*4z os on 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 520 nm f2- yirze -(xx 5dgecl3 bzh3q.alls 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. Whji/9y( at)-ee)v0jyf b y6ro qat is the width of the central m br/(eoj6yta 9 -)0)qivyy ejfaximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. Ifn3:,otx6bu r5* dfd rd the angle between the first*rd n bd5dft36:o,uxr bright fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.ucxtfx6 ,t nlr+ f0i/mx3 v6x.30 m behind a 0.0348-mm-wide slit illumi xrffxv0ux6,il6xmtc/ 3n .t+nated by 589-nm light?    cm

  When blue light of wave(0ai(0n (np 3hv3b ajwjrmia+ length 440 nm falls on a single slit, the first dark bands +h 3 0(jrba 3j(pmawiv0an(i non either side of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm fall8zlw 1dan a/4gs on a single slit, it creates a central diffraction peak that is 9.20 cm dl8g1aa/n4z w wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light sosxy7-)3gb ep94azi xi8i0pbj that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width ox4z3a 7i )p -9sxpi0iybeg8j bf the diffraction maximum for light of wavelength 420 nm?    cm

For a given waveleng,9 -afo7np;wof, zokrk4yy/jth $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-ord5+lky bdzns 8r4pe:-q:s4dg ner maximum when falling on a grating whose slits asn5lk erdpb4q :n48gyd +-zs:re $1.45 \times10^{-3 }\;cm$ 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 h9 1lqdcf6d a,if the third-order occurs at an 1 q6dd9,hca1f l8.0$^{\circ}\,$ 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 is obser5m, 8lqxqmz3*sa f,dy+lrgsqr+k/ g-eyg 9 ,nved at a 15.+rqy3l,gm k zs+5y e9g/rdagnq *xqm,l- sf ,85$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating haat;bymq2 a6h. dpy0r:f/-wbp*o n z 5gs $ 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 normally on a 4dd0 ol3mz-lov +k;dd$9700-line/cm$ 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 gra h 8s-tpx y-x q-qqo6e21xi2cvting with 6000 lines per cm is illuminated with 633 -pqx ecxy2q1o28x6h-i qv st--nm laser light? Assume normal incidence.   

  Two (and only two) fuivj1x+,8 .x i:7 zsaam 1cm:icbw 8hcull spectral orders can be seen on either side of the central ma8:ima +1jwx c,xzc.hiam7 cubis v:18ximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths frwse)u:0m pzd.om 410 nm to 750 nm falls on a grating with zm s.:wdeu0 p)$8500\;lines/cm$ 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 known wavele4-ly t /sg, bo,qnvb-dngth $\lambda\;=\;6.328\times10^{-7 }\;m$ 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 mvv- /k 0)4vi mtclm:tupxr+f8easured 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,8zvz7olwu3:s rc sr. reflected at the center of the outer surface when illuminated normally by white lig zrz l8uo3c: wsr,v7s.ht? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glm6lc d5kap.x ;ass plates are each 26.pc5k;6dml xa .5 cm long?    cm

  What is the smallest thickness of a soap film,cy 629u/xa d lkqgivw.76qwf $(n\;=\;1.42)$ 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 yeltqerz+/1i h+zlow ($\lambda\;=\;570\;mm$ 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 N vr;*pepw*r*sewton’s rings (not counting the dark spot at the c*w;*rpsr ve p*enter) 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 the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically flat glass, as t,oekvsi5 9 ie,dx, 4bin Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick iid5e9bev 4,sx ,ki ,tos the foil?    $\mu m$

  How thick (minimum) should the air layep(8 *yzq lnkgtlq+v/;wo.oi 4y6 xig;r be between two flat glass surfaces if the glass is to appear bright when 450i*ignwz( 6/llq4x8o .gtqp;k yv yo;+-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a qyiyf) vs59j +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 alcohol ,p 78w y/oiuc3l-kv t7mbk .jy$(n=1.36)$ 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 yk4 nzzc2:lv). 24–31) is immersed in a liquid, the diameter of the ei2ynk4z:v )l zcghth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entfv6qxr3ap68 z h+bf*kering an interferometer if 644 bright fringes are counted when the movable mirrorfaf3 pv6hrx8bz 6*+ qk moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an zm o0tm:m4/i4cd5w)pd.zz wv interferometer. When the micrometer is tightened down o v/z c4md45m o)t.0z pdzi:mwwn 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 mirror r:n *. 5h ujz n+nqgrlt579mtm$M_1$ 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. wg0h 3fxz1yknr jc3vq1 ddm )9e2u:9g24–59) 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 areeh:u1gk32wrnyz mx3q)j d 9fdc91 g0v 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 af2vmvj.o27q c: fq*)jk1ghx2dbxf m ;t 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 a) )uwnmn,)sbbx fmnr 9,,tu4 qir–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the lig4pgpt pfee).p 60yo+fht is hitting the diamond.p)60f4 p feopt+ epyg $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximumhg mu6k 753og:c:k2kzzqbuq-cmb2:b. At what angle should one of them be placed so bu2zcq kbu3z:mqc 6kg h b:og52m:7k-that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Px/i*o4bnv3hd+g3 q lter,bn +olaroids be placed so as to reduce the intensity of the incident unpolardtl,i3q3nx4hvbog /b+ n+e*rized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented ae 2t9muay+. kpt 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 38.si;znwwd3 y)+x8ha)h,zqes3 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 3hhg5 .) lm8pne4)3kedubpaf angle be for reflections off the surface of water for light cominaub)d3h p.h5e) m43e klpf gn8g 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 sheets, ea(ks**im x(v1 i tj0scm)9 cjijch of whose axis mak s)9ixi*ickmjj0*(vtc(m js1es a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength qvv 89(y gcx,.(esr m,yk9uy b$ 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 reflectinjigu2cc5r/rm y epc 3q/ +zli)act 246g from mountains or airplanes can interfere with the direct signal fr2mu4 l r /p it6jzrag5cc)2cyc iq/3+eom 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 wiel qt9a g1cmq+ m8p0iiijn3xzu.i j+(90fu*jth .j 9iqgm0z i m+j+8 q*1x n3ueftp jc9ai0(uli$ 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 0.60 mm apart. Tu;gaogfm05i8pz*) n )rchax. he screen is 1.70 m away. A second source of unknown wavelength produces its se8 *m;fg)oxzp .)arnu5iga0hc cond-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 102.1 MHz broadcas*y+j r3lcoe,7 zfri+ yts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fy+fj yr7zo*erl,3c+iig. 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 doorway 0.88 a4 pbbq1by8 eoj 1.;ypeo 7w)hm wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the wwjeb7o1epaq ;1y b8 )po.4hbyhistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single sli8*vm3o6c)2rwf a o ds( rl*wibt of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a serim1av kbql.8f* es of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at anf qvm1 8klb*a. 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 5s/-jc 8xfy zpsecond-order spectrum foy 5cz sj/-8pxfr any visible wavelength?   $ lines/cm$

Show that the second- and third-ordg )9pme.dip7 lvvdz ku5 ;wb2.r (*ylmer spectra of white light produced by a diffraction grating always pi5;pd9mgwlk*uemb(z.lr).y 7vv2 d overlap. What wavelengths overlap exactly?

  When yellow sodium light, xef7f0qw ndsj7 q824p $\lambda\;=\;$ 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 diffraction grating with and the pattern is v13ar83ins jqkvf l;zo3 tbh82iewed on a s8o38t;2b jnirq3 fl1z ak hvs3creen 2.5 m from 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 refraction of a clear mater c,da/mw myj4).qf, swial if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when lightqmj,/ w)mad.yw,s f c4 of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable7nje-*mdr py1 wavelength is incident normally on a thin sheet of plad7yrjnm - pe1*stic 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 neuv: jm-mrhmd1byz6, / r4*ojbeded 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 for the air layer between two flat glasu * cl(alh:ige09b -rbs surfaces if the glass ihl gul0cb (e-*r:a9ib s to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitteo*p n0fomigjbw7 vh8ie, )1 s8d through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and desc*ev i gf8p01m7joi no,8h sbw)ribe 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 zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflect5 nmmle17f jw1ing off a smooth lake is polarized1f jmnl751e wm most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placeddniafh9.g q, : so as to reduce the intensity of the incident un,afq hg din:.9polarized 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 transmission axes are at r,4 wm1yiqhfe0g4oa s8b3 o )8iuk7ykbight an 8b)0ubq ,awyo3 8kfk ye7smg 144ioihgles. A third polarizer is 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 i5m+)pa()u*sarff v g fn 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 1.0 cm and is p 8q6o5zlc-qru he wp;:ointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630pzwl-oqr c8;q 56uhe : 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 eac yoebi/puh9a 8nj7-6 eh 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 63 l:nzkilj p((ojv :w$(n=1.34)$ 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 in ph zpx)0km/y lx--4tedb uuup81ase with each other. They are located atu 0e 4bxk1p-)pyuld/zuxm -8t 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 wavelengths4qck6 l,e9a we, 420 nm and 650 nm, enters a silicate flint glass ewe4eka9 lcq 6,quilateral 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 zgt 2 0mpli*;64up vhlflat surface and 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