Does Huygens’ principle ap4+f 9 a5qd40ind c mhhltc/(bbply to sound waves? To water waves? Explain.

What is the evidence that light isl.6m th)a op5pvr1(sd energy?

Why is light sometimes describedwtmdh. o )ryh1k5.z y.* b3nutp,k*nt as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet both4/wui7 )7fw;axtm yqpa s/ +ch sound and light are waves. Explain the /uxmh /y+4sp;i ctf)7wqaaw7 difference.

If Young’s double-slit experiment were submerged in water, how would 66cwc jyd(oeug1fu ru6/)pt) the fringe pattern be changed6)6 cedup6g)y (uuf1ot r/w jc?

Monochromatic red light is idv+ 5+;pzxaigncident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe g;+v+pixa d5zpattern would change if the red light source is replaced by a blue light source.

Two rays of light frig5 fk/64cuf qom the same source destructively interfere if their path lengths differ by how much?k6c4iu/5qgf f

Why was the observation of the d8ijisc:;v 9 ggouble-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffractiongg: jc8i9ivs; ?

Compare a double-slit experiment for sound waves to that for lighxki6 ed.: 8 s3s1v) kxntre)hft waves. Discuss the similarities a63d1k.e)snhiv8s kf: )xrextnd differences.

Why doesn’t the light from the two headlighq3w5wwjwf n8n fv3.ss (m)cg)ts of a distant car produce an interference pat3v8q g ww)3n5sjwms fwc)fn.(tern?

Suppose white light falls on the two slit:(1cm pwe*qd8or8ppq1o,h fb s of Fig. 24–7, but one slit is covered by w:c8e rm 11fpopp(,*q8 hqb doa red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece cz d2+57h,x8w,tk (f0 /kz mvhexxi ezof window glass, it is not broken down into colors a(/ee+zx72c ivfmx85 zwz th x,,h0 kdks it is by a prism. Explain.

For both converging and diverging lenses, dm;)rkpod 5w6+og)5 h7gxphx riscuss how the focal length for red light differs from that for 7kxmrgp g6;w x5o5)phhr)do+violet light.

A ray of light is refracted through three differentz : 7tsnk5xfy: materials (Fig. 24–55). Rank the materials according to their index of refraction, least to greatestyzx7t:sfk: 5n .

Hold one hand close to your eye and fw (lh7k5,+ me- rsg1uys2mg nyocus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain tnwm(sm7,y 5k-sg +hu gl12 ryehe best pattern.) Describe the pattern that you see.

What happens to the diffraction xv-- ,/jf 6k auc+ l7f)ll);gtntdvvy pattern of a single slit if the whole apparatus is immersed in (a) water, (b) a vacuum, instead ;7a,-c /kf+yl)t vlu-)gvvxl njdt6f of in air.

For diffraction by a single slit, what is ta,n5vww vxfk 8- 4cy*ohe effect of increasing (a) the slit wocv wf4,5-xnk*y av 8width, and (b) the wavelength?

What is the difference in the interference patterpm t0y o *rob298+6r;tfgxorans 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, wbxvg0 v +:d ,m(u1ndl(b) closely spaced sd,gvbn1 v xmw0lu:+(dlits?

White light strikes (a) clwf( ju5a)1cx jc*0 08oavaca diffraction grating, and (b) a prism. A rainbow appears on a wall just bu a aj *w8ccc0f(av0jx)51 olcelow the direction of the horizontal incident beam in each case. 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 normallypa yw l:1o4470 5j35yy-l1 atyqtc ejjvlor9u on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? D3warjo7jvt oyy:4j 0e4l5p lyl 1ayuqt-91c5oes your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a soa3,29u2 lrse- kg 5kiby2qb blnp bubble and not fleu blb 93sr22y n-2b,gkqki5or a thick piece of glass, say?

When a compact disk (CD) is heldoy4ua dc.*aus, 6z t/tyahejn,04 *b k at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochrom0du au ,/hc6bo,zks4n ttey*.*ya aj4atic light was used?

Why are Newton’s rings ji2 5q):tt; vegn.mqv(Fig. 24–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What( g,a2l.tcnce0ne nk * wavelengths do you sug0c *c kl n.2(taee,nnppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where ihabk 0j* jf 98cs+mox(ts thickness is much less cf + 8basx09h*j m(kjothan the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarizatimq+i 1b whw fd2h.*+7auu4 smton tell us about the nature of light?

Explain the advantage of polarized sunglasses ovdxb3r +wvv4u 7er normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizint-qdfht2 x :1j6rp9xv g or not?

Two polarized sheets rotated a sy 5ekryxv /)u)9+nj j(kib-bt 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 skk3tg3,brweuhxktlo(/5l5 / 1mp c/iuy if the Earth had no atmosphere?

If the Earth’s atmosghr nobgkdi y-163nhsn9,,) arv f )g7phere were 50 times denser than it is, would sunlight still be white, or would it be s-bgvh 3kan9yonifrn)6)h 1rd 7,gg s, ome other color?

  Monochromatic light falling on twbgv-nw6 agz e1 )j-c.wo slits 0.016 mm apart produces the fifth-order fringe atj g)1n.z-6gea-w wv bc an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light 5 ,8 utkt d7vdhupbh:)is observed at an angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two very narrow slits 0.048 mm apart. Success,o.:mr2f,wz4)r lrns m- picsive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and foslzi-: c4r mpmnw.2r),rs, frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne lasm/3sqlv 9y: tjer, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apa ytv:lqmjs39 /rt 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 prorh(q0x92o ey oduces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. Wheq0(oxo hy 2r9at is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, hr )j*f/h:iu hv(as 1rqow far apart are the second-order fringes for these two wavelengths on a screen 1.0 *sq) vuahh1i (/:rrjf m away?    mm

  In a double-slit experiment, it is found that blue light ofsph8 qh vsxuyb 95/oq ,n(9zc( wavelength 460 nm gives a second-order maximum at a certain loc/n9zuq 8cp5x(yh ohqs,(bv 9sation 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 pass throughfwm,hy2o1o lhs6u3 n9 two openings 5.0 cm apart ino3u s1fn2wo ,hl9h6ym 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 action?

Suppose a thin piece of glass is placed in front of th2- zzokf4al7c e lower slit in Fig. 24–7 so that thz 4zk 2-7cfoale two waves 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, l:dme p/z3t rx,az,3 fthe 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/t,arzzp, x:de mfl 33 the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm jwvixjv w *61x;-;9wpf x (chgare illuminated by 544 nm light. Find the distance between adjacent bright fringes on;w6w wpigxj(1vf* -cx;x h j9v a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in a 7n9 kg gd5-c(axylvu jb,l,;iir falls on two slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a doub n c sh63f)4rkm3-aoc *zgqe 024mtwe ubztz1/le-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What iso36 -bc0z4aunm * 1shzqm kzte/e)34tr g2fcw the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceeh1vg1 p6b9 hck.cuam +d that ougphc.1mc a 61 +vb9khf violet light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece os6d8n f*ahuv :f glass at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light containing two iilq zbt;: 3wmvu 7idhv :-2c2wavelengths, $\lambda_1\;=\;450\;nm$ 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 widea bj-vibm 6se)c t(x(mgre7 ,(, what is the full angular width ofa6bes(m7ve bmr-, x gjt)(c (i the central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a ) 6st n*xq6 )c6drkyxcslit 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 falls on a slit xe7 h );hcn:akthat 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 lighed.c qcmry0xm - 2)ab xd14jhvy0 fx:)t. What is the width of the central maximum (in cm) in the diffra4be)q cma)f j1c.hdx m-0xy2y0r x :dvction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slibb murpdu7 b(-yko x*9nm l)12t. If the angle between the first bright fringes on either side of the7 1*k(m2bpmb)-dx rbuu9y nol central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen w zuu*q3 s4/otqnw*q:2.30 m behind a 0.0348-mm-wide slit illuminated bys: 3uuowwtnz q 4q*q/* 589-nm light?    cm

  When blue light of wavelength 440 nm fal k +ytv:v/( co1:fxfecod sxxi 2s.0m*ls on a single slit, the first dark bands on either side of center are separated bes:10vyk(m s+* /ff2 toxc:d .vixo xcy 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelq2qoz 2 (ci/lmength 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 mmloqq i2z(c2/ away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so tha .pofx0hfj-doo8 ( 5bit the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, wh dix 0( b-pjof8.oohf5at will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengp*hilh-7un ck 8v(z5y th $\lambda$, 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 n957 i oynw;wlmaximum when falling on a i;79w5nwol yn 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-orde+/ggefdql .1 o5cd:iyr occurs at an e1cg5o:d./i qydf+lg18.0$^{\circ}\,$ 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 o 2q kx 8xp:v0oip5b.bs15rbikf 589-nm light falling on a diffraction grating is observe82rp51. pkbbk o:v0qsxix 5ib d 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 has wg05yu;dg2xc-s1t*c/dp dpw $ 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 wxa ,f oxaen4 3oj 5 v*-v5(,rtcsq3bh$9700-line/cm$ 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 orde9wak, 5rimo ue,.yjhd02 k 0cmr that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal in 9kr,ce5,amwk0.ydim 20 j uhocidence.   

  Two (and only two) full spectral orders can be seen on either side of the cewhq1d y *4 ev ushj9f,zwp3r;6ntral maximum when white light is sent through aevh*y;q9wwfzj u6 p14,sr h3d diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a gratin.,xmgz:+ wt3npu2 fvqg with u: q.2w3v nfx pzg,m+t$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatizvk0/- 3uveb4 tj x7suc 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 lines are m s qwd28ozgk).9ql30vgap ll: easured 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 mosn4zuu8)fd q.)b l :oybt strongly reflected at the center of the outer surface when illuminated normally by white l8)uo y4bdf qn ).u:zlbight? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 2n:32b6 5oy4b adgezlz4–8 if the glass plates are each 26 one6bz:yldz 35bg a24.5 cm long?    cm

  What is the smallest thickness 9 -xffx6dwa a9of 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 yel6hy99 vmww:ytlow ($\lambda\;=\;570\;mm$ 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 bright6f+,4od bmq7 ghd igl8 and 31 dark Newton’s rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens restifgo87h4bmgld,q d6+ing 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 lvy-sm +b7n0m1b s./a4m trcp, as in -r m t4a0psb+sy. /71clmnvmbFig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two w2j6c frfcs/:g:d3srj/ o( tsflat glass surfaces if the glass is to app:f/d2r6o/f(stcjrg3c: js wsear 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 stoleka2 yig23 pwsk /q)w8fn 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 scczkhmrd) -uk 1*g9k gsw: +)$(n=1.36)$ 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 li)j4z zj w,dn2fquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refracj2zn zwj f,)4dtive index of the liquid?   

  What is the wavelength of5ox.j*nckx m6 hetx5zu r at6 0+ze2f0 the light entering an interferometer if 644 bright fringes are counted when the mo t0z *56xe65xmu2noxc 0a +k .tfrehjzvable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movajk+ul:iu,9/ruhn 3z pble 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 micrometer, is 272. What is the thickness of the foil? The wavelength of light used is 589ju nup ,uz+ih 3:/9lrk nm.    $\mu m$

  How far must the mirror e9tsl:y;n 0+d4vbx/ bzukidq 1r1n2n $M_1$ 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.3ahs+zoq)z1 zhuq(3nc+o ,fsuct ,b 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 pa 3qbhc,+t n fs3zshu zacuqo(, 1.z)+ost 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 ori6,i;. r k,g5fumcwajiented 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 a jx,x(7 wrgu .zt)1c+sky+adc*r cxa0n air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle fo3h aode3 d /m3l0ssh7cr a diamond submerged in water if the light is hitting 3alsdh 3c3mdsh e0/ o7the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing tp3pp*+ns2 -dc lhiu)fhrough them is a maximum. At what angle should one of them be placed so that the intensity is subseq)+n2d -3fpi pu lphsc*uently reduced by half?    $^{\circ}\,$

  At what angle should the axes sf v;- wvbtek2c k9h+;of two Polaroids be placed so as to reduce the intensity okth ws+f;2;bc ve9v -kf the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriem x9 )bkz,92wwz pm;z*g/b -h*hojkqhnted 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 orien931ubzy0 h*etqt6brfsm7 r:ited 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’s angle be for reflections off the surface of water for l :vj:ggq6zg(5jcra7 )1wfr nbight coming from beneath the nqf :baj:7j1gvrwzr(5 g6gc ) 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 succe+-z 91,nsl2he* wmlb bsic2b ncpr7. kssive Polaroid sheets, each of whose axis makes a 4zrbm 2p9e b c+. nl wns,l17kb-ishc*25$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength mjs9t8u )f j-s$ 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 interferenx:plg o n;f)ci2ga 06 with the direct signalgx 0o)fn2l:gn6 cp;ia from the station.
(a) What kind of interference will occur when 75-MHz television signals arrive at a receiver directly from a distant station, and are reflected from a nearby airplane 118 m directly above the receiver? Assume $\frac{1}{2}\;\lambda$ change in phase of the signal upon reflection.  ----待选择----constructivedestructive 
(b) What kind of interference will occur if the plane is 22 m closer to the receiver?  ----待选择----constructivedestructive 

  Red light from three separate sources passes through a lpieu*e0q,0o8 rj 9zrg+kvl 8diffraction grating with vz0pqugi90 +,8lek o 8rjr*el$ 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 25qn 3e tfg*kvapart. 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 maximum than the 590-nm light. What is the wavelenn * g5ef2ktv3qgth of the unknown light? $\lambda_2$    nm

A radio station opers3 (+ npya .3f9ceujamating at 102.1 MHz broadcasts 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 horizon3ca+y spaj.(m 93unf etally 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 bac:ouio2 .wnmq2cyyb8 a:. 0ev)-fsrg vk from an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not ms aqvo)i. .:ngb:eyry8wfv 2-0c2u opossible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a singlhel;u+s7 4isz e slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across them. When )cky k/0dfqehs+. g v1jyq1(z normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an angle o(hzqj1 vek1ygy.0fk cq+)s /df 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must ax*ej6e* ; z wz chxgx:qxe8vtdmm(+*6 grating have if there is to be no second-order spectrum for any visible cev:zexj 8tdxe* g;( hwm6+6m**qxx zwavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light 28cnl-7 0hrc/tfvhpl produced by a diffraction grating always overlht h 7/0rcn8lvfp -l2cap. What wavelengths overlap exactly?

  When yellow sodium light, h6xta8x0j yt* $\lambda\;=\;$ 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 id g6m:rbimab 7 m ,h*6gd/oj0cs viewed on a screen 2.5 m from ag/i ,bmj 6m:6rcm0ogd dh*7b 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 xlv /8c d( ga,evh/wy;if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you hx vy/dle/vwh(a8gc; ,ave a choice for an answer?

  Monochromatic light of variable wavelength is incident normalgowy)wc ei)b j, k) n9w(yq9a8ly on a thin sheet of plastic film in air. The e,i )w(yj wga)w b99 8qcynko)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 for an anti-ref0hl op/7in)uelective 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-zer pwp 2z,9ni,j;(h7bpy 4 ebm:t .hbhyoo) thickness for the air layer between two flat glass surfa;w,h(o.ti h 2:y9ep,pbpyz4 mjhb7 b nces 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 oj241 dikfiuw*n 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 jiw 4dkfi* u12minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflecting off a smooth lay4z;b7 zbaeq ,.ha/fn,vprj /ke is polar7r hez ya;z,npbv/q4fb a/ .,jized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polm 7 3tn(x1hweiaroids be placed so as to reduce the intensity of t3i1wtnh( 7mxehe 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 po c pfk22ay+rt)larizer sheets whose transmission axes are at right angles. A third polarizer is placed between the first two so thatpy)c+2 fa2rk t 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 vertica(noz3 jiuu4vl:b(l2u qtx i( ;l, 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 of32ugprhu-/c j width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne lasec -ghj/3rpuu2 r). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are eacv23a l 5ncoqb)h 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 q l+4:c yens3s$(n=1.34)$ 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 phasepw6 1g7o* gie d588q*nqymnfo with each other. They are located at 1dy mf8*7np*5 gqiwon e6g8oqpoints $S_1$ 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 wavele ;/. zgpbbtqct+ d s)ihtv 95y df4vq3o7p(in*ngths, 420 nm and 650 nm, enters a silb tt t ohdgv(.qnpb fiid/p4 sz9)+c7vq*; 3y5icate flint 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-2but *z :1vujbsmc y* flat 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