Does Huygens’ principle app,c2 )nc(jlz uogxf;x(ly to sound waves? To water waves? Explain.

What is the evidence that ligheg vn9r) 0eqp7t is energy?

Why is light sometimes described as4uz7/ bj+4ate nvz 4gq:4po hr rays and sometimes as waves?

We can hear sounds around .a+ +hplfa)on4pb; o x+ (tvaucorners, but we cannot see around corners; yet both sound and light are wa++phat a+p(n ou;).xb4folav ves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how would the fringe 0 k zji72il t*,jdjdh2ftu,y(pattern be chl7i f*t ,2i ujdh ytjz,kd0(2janged?

Monochromatic red light is incident u97:-ddcw 7jjwwa :fs,7f jveon 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 replaced by a blue light s ,7sjw vw f:uaj -:ew9c7dd7fjource.

Two rays of light from the same+;l7 rntqx ii-:jzc f5 source destructively interfere if their path lengths dif5x;j +cqn:lfzit 7ir-fer by how much?

Why was the observation of the double-slit interference pattern more convincin mk-akrj 3:gtgh+;- q sitd3s(g evidence for the wave theory of light than the observation of diffraction -3(i:ak3k hmd st;rts+jg-q g?

Compare a double-slit experiment for sound waves to that forl ,u z9.um:xco light waves. Discuss the similarities and diffexl 9m, ocuz.u:rences.

Why doesn’t the light from the two headlights of a distant car produce an inter(ep* c95 d ehxm0d-wnlference patteew5ex np- ch* (mld0d9rn?

Suppose white light falls on the two slits of Fig. 24–7, b0g b b8qtcd8g,ut one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern qbt8gg c0 ,8bdon the screen.

When white light passes through a flat piece of window glass, it is not t 0 7wk l2 g9,08gbasd-ujtzqcbroken down into colors as it is bt0g0jqzut-ba7 dg k8lwc92 s,y a prism. Explain.

For both converging anu;*pvfduf ; ey9i//mwd diverging lenses, discuss how the focal length for red light differs from that for violet light.uf uyw/ vef*pi;m/; d9

A ray of light is refracted through three different materials (Fig 3bena)/6y)dwme+wf o. 24–55). Rank the materials according to their index of refraction, least t/63yo ewn a)ebwfmd) +o greatest.

Hold one hand close to your eye and focus on a distant light sourr 5l +26w5,iazvvytrgce through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe thlg w5i,+ v5rt2zryva6e pattern that you see.

What happens to the diffraction pattern of a single slit if the whole) e. (.hzqn maqwb6wd7 apparatus is immersed in (a) watb. he(mq 7wqd)nw6 az.er, (b) a vacuum, instead of in air.

For diffraction by a single slit, 0g of9o:.ltfmz cem,:z 6 u/xx djl;v-what is the effect of increasing (a) the slit width, and (b) the wavelelo.ve-ul:t9f: z o/mx gzm j6f0x,d ;cngth?

What is the difference in the int(jzqe f0 pj )d(ywjaklsbk6x 8-3 ty;*erference 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) many slits, (b) closely h*gvc la2* avub3gi. (ykt8r2spg*.k3 y(t2rc ivlhgaavb 8u*2aced slits?

White light strikes (a) a diffraction grating, and (b) a prism. A rainbow appef(8 sbvmr x0e.ars on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow vb0xrfe(s8 .min each case? Explain.

For light consisting of wayyhji s3 rq0ira.q;+c :- mr(uvelengths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap+r .-yhqyr s 0am: i(jcqu3;ir in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a ujil l5v:nr j6ix25t:thin film like a soap bubble and not for a thick piece of glass2 t ul5i:x i6jrl5jv:n, say?

When a compact disk (CD) is held at an angle in white light, the re b0h0l2t8io z4fyidh*g.w ;zhxp p5 7jflected light is a full spectrum (Fig. 24–56). Explain. What would ypyx8dgtp o0b0 h2fiw.i5;h4 z h7zjl*ou expect to see if monochromatic light was used?

Why are Newton’s rings (Fig - gc.hlb:s75aw8egnq . 24–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light9re nsgw )30sg 8qnjd+*j0j sp. What wavelengths do you suppose the coating is designed to transmi ejjq3psrjn sg8 w)09s 0n+*gdt completely?

A drop of oil on a pond appears bright /sgk.uxh0/g roc/k*1kp xwf 9 at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the i/x xp rkgscg 1ou/fk9hw*0/k. ndex of refraction of the oil?

What does polarization tell us about the nab o-f.*fbet se7cjnkw+q7,, vture of light?

Explain the advantage of polarized sunglasses over normal t(xp,hydj1sk:fk3 yf0 inted sunglasses.

How can you tell if a pair of sunglasses is polarizi1cpb hoj2jp 17ng or not?

Two polarized sheets rotated at ansg gf;* ,wee,v 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 Earth j 3r)8 im(opzcbzae ;0had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it ah5 -k: bn wiu1* qxwhym1+4ekis, would sunlight still be white, or would ihex5i m1bw aw- q4y+k*khnu:1t be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-ordery *nfk1mmt/+t fringe at tnkm 1t*/y+mfan 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 of yg918fbfbyn0bv;pukgt8/rmo i;*(d 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. Succesbqft/;i-;d jzbq 7 -fksive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavel- t;;fb/qj7qdb- zki fength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nm, fallsd7yuemwcx3;3dfa2ez ,g 8 zq7 on two very narrow slits 0.060 mm apart. How fa 8uq2eaw3y7xd,f 7gd c;3 emzzr apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on . pomo eg2jg .027zauztwo 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. Whg 2 mz7o20aue zo.p.gjat is the separation of the two slits?    mm

  If 720-nm and 660-nm lighiy9 j i-zgs8q1f5h,jgt passes through two slits 0.58 mm apart, how far apart are the , j8h915jgg- zqyiisf second-order fringes for 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 nm g(t*oa9aez oj) ives a second-order maximum at a certain location on the screen. What wavelength of visible light wou9* z o)aetja(old have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings 5.0 cmz psjet -1(esy5 //tiv apart in a board. 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 ace5j- /1sy e ttsizv(p/tion?

Suppose a thin piece of glass is pl:n, c6+uo1ztimh ; x6zm g:qcraced in front of the lower slit in Fig. 24–7 so that the two wav ,r 66zo z:miqm 1c:c+hntgux;es 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 maximuej 2f2a: 7jp*qf5 inuum 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 projected through the same slits. How far from the central bright su 5* e jqjuniafpf:227pot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544o3pk oli apg*5(8i.ao nm light. Find the distance between .oik5pg( aioo 8pal3* adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air fal;z;ks *p:2cy wb5 cafpls 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) covermkhd 7 1a qo);tp)ix3oe ztc,;s one slit of a double-slit apparatus illuminated by 640-nm ligt p,)c ztm eak);dqi 31h7ox;oht. 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 rex(wya z;z /nh7d light (700 nm) exceed that of violet light (400/znhy w(;7xa z nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a p87uwyf+6h oh4u k- rlpiece 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 lggm9t+qb grt16y4 s9sight 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 fall my53uthbp+36cys*1u6ebo +gh5ll jp s on a slit 0.0440 mm wide, what is the full angular width of the central diffraction peahpy+yge*obc 65ult3 1mh3b56splj u + k?    $^{\circ}\,$

  Monochromatic light falls on a slit s7vbijt16 p+ :4dc aqcicx- 1nthat 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 fallsp*wofe2fi 9hy-pg 5 p; 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 whlk n6-s / *5rqds9yzis illuminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a screen 5.0 m a krq5nszdls9-* 6why/way?    cm

  Monochromatic light of waveleng,vxc0p4r( yryth 653 nm falls on a slit. If the angle between the first bright fringes on either side of the central v, (40cyprrxy maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a so8up x gpc,d:4 y7(oqucreen 2.30 m behind a 0.0348-mm-wide slit illuminated by 58o u(uqpo 7p:c4g8,dxy9-nm light?    cm

  When blue light of wavelength 440 nm falls on a :w/5yuk6uw c k8ewi2z single slit, the first dark bands on either side of center are s uww:u6icwk2 zye5 /8keparated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelen;2.b 4 ylj8/9a7slfaohwe wg kgth 415 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 l/h;eajsbw.4 l2 a kg9o78y fwm away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so)dngvcp22t i : that the diffraction maximum is 4.0 cm wide on a scree2)gp in 2dvct:n 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt1tqs*: hthx2 mh $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm lighttk0py+ yf*;3v:3q pqyamn:dxp fne5a18dz; s produce a second-order maximum when falling on a grating whose slits ar 0 k3v yafznex:3q pa:fp sy1d;;8m+n*tpyq5 de $1.45 \times10^{-3 }\;cm$ 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-orr+l s;x48jvlg)rl2 gr5ft nr tr:9:hgder occurs at an 18. grll sj;g45trt :)x8rrfr:2n lv hg9+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 x+0pq7ht(z 0* okdq f6frfbr :589-nm light falling on a diffraction grating is observebqfr0tk*d r+z7o6:q f0ph x(fd 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 gratinkv*(pb( 6nljizd s-pz)c9wh (g 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 normally on a0:io4 b ol:ooymo wvjr(,fgy: u1q32h nz1i2v $9700-line/cm$ 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 spectk(bl8- eqo-5o, m.da8 txbmmxb7v 9fd ral order that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal ine bklv(m5t 87odqxmd8f,.bb o9ma- -xcidence.   

  Two (and only two) full spectral orders can be seen on either sitc ee9bcu,i0 ;de of the central maximum when white light is sent through a diffraction grating. What is the maximum numbe ue i;t09cc,ber of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelenr(k zc 3 e )cdijd/fcnwia.-h )o;ws46gths from 410 nm to 750 nm falls on a grating with .aic-r6e/o)n4d shf jk 3zdcww i ;)(c$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which6je-rbdd3) awf+8 cqgnyx ov6ri 8c 47 produces monochromatic 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 spectrum l6gk )0kjcv.c kh (oa1jines 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 resuwf :kl)h0q3 flected at the center of the outer surface when illuminated normally by white light? Assume tha):f hs0wlku3q t $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24z1;v8te6 ekf b,8 muflga52tn–8 if the glass plates are each 26.5 cn fef1t; ,vleg ak8uzmb856t 2m long?    cm

  What is the smallest thicknessc b8m;hszg 5x/ r3mv)dov(tj8pn9 oa) 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 yel67 )va+zgry68 jgf dzpko( *txlow ($\lambda\;=\;570\;mm$ 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 t7y+x9ccdj.ws;3*f8c xz 4c ebcq *ifqhe 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 the center than the edges? 48;c i f wc9jqdecxc.*f 3*7bqx+cyzs    $\mu m$

  A fine metal foil separates one end of two pieces ofyjku 5p8/.ep0il3ks lsqr k; z)u0 gfu05y c)w optically flat glass, as in Fig. 24–33. When light of wavelength 670 wspjky .ugq0s5)eylzp58u0lk3 ;i r )f uk0/cnm 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 betwee.+xz jw(0 u u)go,lz *ewk3ezmn two flat glass surfaces if the glass is to appear bright when 450-nm light is incident normally w3(l)o gekzz u,zm0xej*u +w.?    nm
What if the glass is to appear dark?    nm

  vA piece of material, sus6fv1 isj. fff-pected 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 alcohocc6yv013-hx h:w;xt)ov2m ) iavp jasl $(n=1.36)$ 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 lupw:js4xy beu vx*r5v/v(c l2/j i2x9iquid, the diameter o bv( s2ic2 w/5vlj9r/u4v:p ex uy*jxxf the eighth 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 entering an interferometer if 644 bright 2,g9b vss5vb r clzvdtv;(( *jfringes are counted when the movable mirrc(dz sb tvgb(2rv*v,v j;s5 9lor moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an ygm+:k8. jtzointerferometer. When the micrometer is tightened dow: yto .8jkgz+mn 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 mirr-m(atk91zgcchh18z .(g vvrw or $M_1$ 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.l517 g5qjaeo+yhqoc:p+qpfo 81 wcv- 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 movoyfwpl+h87ocq5 :-a1 +p15govcqq ej e 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 nap g05(-9olzwnq :(o tixzxn;xz+-y 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/wfsg;s eu(rwr d)t)3hbecx11ie r 17 air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if thedat vt4.9 qwfxkx*-2z light is hitting the2vtxxa 9dfq4.-*t zk w diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the p,blxdqf 2u5rw:y4m0s64ynq light passing through them is a maximum. At what angle should one of them be placed so thatsxm5 q r0yd2q4np,f6b4 l:uwy the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of tw+hqhin96n)l *7 upjd ao Polaroids be placed so as to reduce the intensit ulq7d6 n*hip9jn) ah+y of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at jdmc(+ :;olay1n qyihi6)* ia 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 38.0z.xpx7, f(d7 dc elje0$^{\circ}\,$ 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 re*/ z0r ,u40y nttq ikbd3-alutflections off the surface of water for light coming from beneath the surface? Compare to ttn u3likb a 04y-q,0tu/zrd* 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 pa e5o*8rui mok)sses through five successive Polaroid sheets, each of whose axis makes a*)iek5 8umroo 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength s:cr 2 yojm/j) hj3ep2$ 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 airplp87k. 0lz aexqanes can interfere with the direct signal from the z8pk0xe.q7 lastation.
(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 /m/dkv xrdkayt)ou +bhzb - 3f2 k0+/qthrough a diffraction grating with v/// o dbdr -tqh++3kmbakxz)fy uk20$ 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 pasg sv 2k-4-einp)7yssases through two narrow 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 central maxim sn472 a-siy) sepv-kgum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broad(fw*q as3)l vucasts from two identical antennae at the same 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 tak q )*fv(3sualwen 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 outsidzedxtxn3938 6tyqna;e doorway 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 ny n;3tzt3ea69xqd8 x the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falll2c b/qhmhfs8*t2l2 rs on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have x1f7vkp px6 ;)qqb7byu/1ygca series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when view guxyp;1k6q7f pxby7b1v/)c qed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a gratis5 *+rl r8 *bzj.we xmdz4j/ukng have if there is to be no second-order spectrum for any visible wavelenrljed* 4s8urk *bx j./w5m z+zgth?   $ lines/cm$

Show that the second- and txxctj o5sailec2( jdda87/x5+y2 1j phird-order spectra of white light produced by a diffraction grating always overlap. What wavelengths ovej jp ac x/5 5 (xiedj7t+2adc1yox28slrlap exactly?

  When yellow sodium lighuf9prl/oi /f usi;.9 it, $\lambda\;=\;$ 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 patternyiu 6tt c539mp is viewed on a screen 2.5 m yi6 5 3mpuc9ttfrom 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 material if a minimum of 150 nm thickf8o aqqhzftrf rj 5y nq(16:4/ness of it, when laid on glass, is needed to reduce reflection to nearly zero when ligh4qf/5 th oq(8frz1fjq6ayr n :t of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident normally on a th o7p 5jyw,3cynin sheet of plastic film in air. The reflected ligop w7ycj3n5y ,ht 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 for an angno0shy7.i7*mds xwx09:qiybz ma.4 ti-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 betw+x43ckvgwuf9 een two flat glass surf+f c94u 3kwxvgaces if the glass is 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 transmitted through a thin film layered on a f 0 sz*etztreo 7juz+53, qir8ktd-j 5vlat piece of glass. Draw as3tdk*qo5+ze0 jt7 r z-r v8jiezut ,5 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 zero.
24-30
24-36

  At what angle above the horizon is the Sun when lightu; ryq4i5q. +4rxau cdh:ie33 s b9bwi reflecting off a smooth lake is polarized mos+r c3e:;qsu3dr 9.yxh5uii biqa w4b4t strongly?    $^{\circ}\,$

  At what angle should the axes of twokp9(7 3fcxmf c Polaroids be placed so as to reduce the intensity of the incident unp (cf xmk93fp7colarized 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 transmissi0h nxd0uk8/t(q whq -von axes are at right angles. A third polarizer is placed between the first two so that it(vq/qhnhwkut0dx- 80s 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 a v:q;jjrfufv s3f*ay+g +hc3.xes 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 throughqxy 9lr-44 fyd i*3eah a slit of width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emii*elx a3 4y-yrd4 9hfqts 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 10:fcr 8w, h whcq4z.r4m lyv4 5udp8.jl17l yez$^{\circ}\,$ 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 r mpmj)ty /ed0k+ ;i9u$(n=1.34)$ 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 radiok a4xxje )(dw;j ;os9a waves in phase with each other. They are loakj( eodx )x as;4;9jwcated 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 lighoe0t;v l3,i l(te 26u*nyzksht containing two wavelengths, 420 nm and 650 nm, enters a silicate fli2*e;lsi tou 3h(kteyzv60, l nnt glass 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 surfadq f +p9rw6akn u)+*gfz /t;bgce 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