Does Huygens’ principle apply to sound waves? To water waves? Explain. npi bwu9c1mp0g 7e+s*

What is the evidence that light i*ngvmz8/h6-u 2pdvg3g0v ist s energy?

Why is light sometimes described as rays and sometimfudu8 .z/31febnn q p;es as waves?

We can hear sounds around corner/j-kr hs1e *)did5aucs, but we cannot see around corners; yet both sound and light are waves. Explain tk5usc)e dj1*- idr /hahe difference.

If Young’s double-slit experiment were 1 .r0 3opefc+: qqzdyf(y(evgsubmerged in water, how would the fringe pattern be chan g+e(oe:y.qpf 3 f1rz0ydqc(vged?

Monochromatic red light is incident on a double slit, and the interfe t(igj9*nyu. ex9zgf : gf;bm1rence 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 lg;ez9n gxtj g (bufymi:9*1f. ight source.

Two rays of light from the same g 6,nvd;yajur dv; a4;source destructively interfere if their path lengths differ by hvr,; ;j4v6d da; ganyuow much?

Why was the observation of the double-slit intebw(fzl 9 a:a1m8ya8t p fj9wo;rference pattern more convincing evidencef j a9 t(lf:1;obwwz88ymaap9 for the wave theory of light than the observation of diffraction?

Compare a double-slit experiment 0r -7u yi5xzlyfor sound waves to that for light waves. Discuss the l7 riy-0xu5 zysimilarities and differences.

Why doesn’t the light from the two headwf id -n;s khiqs3(l*8lights of a distant car produce an interferlhkf(3; s- 8swqdni*ience pattern?

Suppose white light falls on the tw u2 fr ,wt-k5tp+cx/ioo slits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and x fkc ur+ p-,5ttow/2ithe other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glass, it is not br l-4jauu sxw3t wq/b7ga ,0gm1oken down ins1/q3 uggu -jw lm4xw7at 0b,ato colors as it is by a prism. Explain.

For both converging and v 14j:ybs.uk*ek; qka diverging lenses, discuss how the focal length for red lighjbuk.1v4ks;*e a k: qyt differs from that for violet light.

A ray of light is refracted thr nf;vx:dea f.zpz8u:/ough three different materials (Fig. 24–55). Rank the mate:8uv dzp/ zne.fafx;:rials according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a d1o3ulrq 4rti0hu5dkb pdl8d i+ ,q)( xistant light source through a narrow slit between two fingers. (Adjust your (xbp 5iko3u l 84ud dlh, 1rqr)qdt+0ifingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffractyjv-4pzd2 c:ws(z6 x(t mo 2bb(vj/ ukion pattern of a single slit if the whole apparatus is immersed in (a) water, (b) a vacuum, insteak6 ujvpb : b jxdz(w t/24s2-cmovz((yd of in air.

For diffraction by a single slit, what 5qv7gyo+ q52)kdxjupis the effect of increasing (a) the slit width,k7dog55+ uj xq yv2pq) and (b) the wavelength?

What is the difference in the interference patterns f* m jla1f6/e,nkn1hijormed (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 e 2f,myc6/r noof (a) many slits, (b) closely spaced slym2nfc ,ro6/ eits?

White light strikes (a) )a-h( p vqite.a diffraction grating, and (b) a prism. A rainbow appears on a wall just below the direction p-)(.hate iv qof 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 nlco1195nda9td ;npnsormally on a diffraction grating, for what orders (if any) wn9snd; aldnct op1915ould there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a sfbo ,+ s 3d:hpxv:7fhioap bubble andb:,dh: v ffso7xp3+ih not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle inasy79 zmwn :x7 white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expesna: xy7zm9 w7ct to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from thn qqv0e0 kko 7*l:y/jde center?

Some coated lenses appear greenish yellow when seen by reflected4fai5cq.df ve. a8-xa light. What wavelengths do you suppose the coating is designed to transmit completely-a.e5qixfdc v a84 .af?

A drop of oil on a pond appears bright at its edgesyj a/; kg f;jhzzdb5:aq-n( a-, where its thickness is much less than the wavelengths of visible light. What can you say about the index of rznzda -qg: ;jkabja y-;fh 5/(efraction of the oil?

What does polarization tell us adltao7 m0,bferd60 8c bout the nature of light?

Explain the advantage ofd*xfp9 d t9 ,qu*vlen(6tsrof t+ip)wlu 9a9 + polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair * rw3jf x2ecg 8fmdmvh82:6vx of sunglasses is polarizing or not?

Two polarized sheets rotated af:x/vn1+ md6mfp m ju6mvke 4jh.h b2/t an angle of 90$^{\circ}\,$ with respect to each other will not let any light through. Three polarized sheets, each rotated at an angle of 45$^{\circ}\,$ with respect to each other, will let some light through. What will happen to unpolarized light if you align four polarized sheets, each rotated at an angle of 30$^{\circ}\,$ with respect to the one in front of it?

What would be the color of the sky a2ljfj5 -oizrb k;-3i9y1vim if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is/f4ojmcxy gyozp5,8r9n6v 9xdb jaw0/c3i 8 i , would sunlight still be white, or would it be some other colorc54 a098w vr,o8/cdz 6 fp y39 nbjgjmiixo/xy?

  Monochromatic light falling on two slits 0.016 mm apart produces *hqb pu*zdi (1*. hpqothe fifth-order fr*(q**hpohzpb qu1 i. dinge at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 5m0c5cd zlty- 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 two very narrow slits 0.048 mm apart.je9l)fjjl* +g Successive fringes on a scree*jglfl)9j +j en 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nm,09ujw9n /o7+cre:xh vxzpf e : falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of t xnw : 0x9r 9:puezhvf/+e7ojche pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and pobvq84go3iiw yp (.f- roduces an interference pattern in which the fourth-order fringe is 38 mm from the central fr -yop.fiw8b3qov g (4iinge on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes amso(gwvss;4nt* *0nthrough two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengtnw*mv* s;a0t(ossng4hs on a screen 1.0 m away?    mm

  In a double-slit experimennmq 1x1:+ ezhjt, it is found that blue light of wavelength 460 nm gives a seconnqe1zj x:hm1+ d-order maximum at a certain location 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 through two openings 1em1b.f* )oct34tlvk f nig;d5.0 cm apart in a board. At a point 2.0 m b1d;4 nf ivc)tgmbe* 13ftol .keyond 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 frqr te),rxkitj,v .9ck(o 5+k8op1flxont of the lower slit in Fig. 24–7 so that the two wa xkk8v +c9k.,qpx5ot)jr it re f(ol,1ves 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 thiear +++gkx je42 msbi3a; o7qkrd-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 slits. xs o;b+g+m+eae473 2 kk irajqLight 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 by kfuw/ knpwu;ey35v8m9-e -gv544 nm light. Find the distance between adjacent bright fringespy8; fwwk /m- 5evgkunue9 v3- on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air f0xeeox+tl nyy/jc1a5) t95r 1 hz5uipalls 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 o q,55lndm zjou a2+.ikf a double-slit apparatus illuminated by 640-nm light. The center point on the screen, inste2zij n a ko5,dl.u+mq5ad of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed thatx :o4mtg28a ic of violet 4im 2:ox 8gctalight (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes3y/ l sew+krz+8*f avy a piece 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 ligyd/pjtyou;/0*gez7nv a op3. ht 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 0.0440 mm wide, what is the full a73 u-t4up vj*ryp+l 9yjyy7qj . byyh+ngular width o*lpy u3y9 y+74yjq+-7b u yjrjpvyht.f the central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that:kvb.x5 q oruav*)1 w-zf6bsi 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 fvcgzdyd5r 5jh4;y zfo+f 1+4520 nm falls 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-k a22d fgnhtjy :l/q1. What is the width of the central maximum (in cm) in the diffraction pattern on a screen 5.0 m awaqfyn1a:2 -tk2/ghldjy?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. manwy8r*/ v. cy.-t6 eot 8qe )les*uuIf the angle between the first bright fringes on either sidyy *ewn/6qu mc.t8 e )ouvlr.8eta-*se of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m behind a 0.0348-mgi em f5 7 fjrtv7mzcwj-(+*h)m-wide slit illuminated by 57f tjvw)czmj*-g (57h+ ie rmf89-nm light?    cm

  When blue light of wavelength 440 nm falls on a sinepb oyo zh29z39lpn9/ gle slit, the first dark bands on either side of center are sepanb eyz3pp92h9 /l9ozorated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 4 4( php+sgiji015 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 (0 4+pip shjgim away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction 1v*wn 3 .bkq8zjisx;umaximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light of wavvzbj i31w .8ns* ;qukxelength 420 nm?    cm

For a given wavelengtu. osvr;d:su.7dk z1xedx.2 q 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 maximume,c:m 8f e-kna when falling on a grating whose slits arc:akn 8mee,-fe $1.45 \times10^{-3 }\;cm$ 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 th ox ga5.xzix b( ;ue6:2yelt-gird-order occurs at an 18.52;oge t 6:lxy (gua.bxzx e-i0$^{\circ}\,$ 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 dixozjph.* y) )tuv u1h+zj:m8hffraction grating is observed at a 15 o1uvu)p :hmjyz *)t.8hxhj +z.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating has 25(6y h yi ki(6m5.akwvvfokp$ 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 normallyb z06vo7r 1k2f 6wpsew5bz+zc on a $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order that y e8z5,g .fqkycan be seen if a grating with 6000 lines per cm is illuminated with 633-nm lasy qk5.yf,z8eg er light? Assume normal incidence.   

  Two (and only two) full spectral orders* )k chz5;ghrl can be seen on either side of the central maximum when white light is sent through a diffraction grating. What c5* lg;rh)khz is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wave3-d/ ww qi pwvq.+h6qnlengths from 410 nm to 750 nm falls on a grating with 6ww + -q/di3pnqqh.wv $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces mon8r;av8e nyrm iw;0h5 td2 4cbnochromatic 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 ar rxyj-s9y 7r(pw wjc+:e 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 wavelengt7uzw:+ htgi-q h is most strongly reflected at the center of the outer surfh gwi:uq +7-ztace when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes m2b,ot/+v 9xe)iapj/nuc p o0in Example 24–8 if the glass plates are each 26.5 c x9nj2/ t)v0 ipc+o,bmae puo/m long?    cm

  What is the smallest thickno9jqto0hei1uyo /1 m+ess 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 greeniqsjj52 s kr 8gq mxnm:c9dzum,2d6g79 f9qh- hsh 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 3ngn - n sgcs1+t3wv8*c1 dark Newton’s rings (not counting the dark spot at the center) are observed when 550-nm light falgt -8cs3n cwn+*1gns vls 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 opte3dar*0wr d.2mfkg:z 9ly2g8 jiuw.eically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How la3ed :u0gzrw kr2.9ide.8wm2yf gj * thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two fl hq7rzh(m;cd arz+,tfitc6n ) qq(t)9at glass surfaces if the glass is zt(r;dq fr)h)9 a76 c+,qntqi(cmt hzto appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being ag8ci 9 f(ir4 5nnou5.d rinnp9x. mc-p 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 alcohols ; uc-bxk75aqn x6c8i $(n=1.36)$ 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 incu;b5/7o* 6 sv0 gekr bx/orfu a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What isrvbg r;e/*s6 70fcbuouox5k / the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 brigh9zv(,s qx/p 70k bs dth/dfcv7t fringes are counted when the movable mir,ddvcx( /7fq/z kpsvs 97th0bror moves 0.225 mm?    nm

  A micrometer is connected to the mot:() z6g,h5dubh :nsa ys sfs)vable mirror of an interferometer. When the micromete g:b:t )z5shs f,ds6u )nsay(hr 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 589 nm.    $\mu m$

  How far must the mirq1p-rz p,3v2mp x0wgglkw,y4 ror $M_1$ 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. 24-;urk*pfn z s hu5a+f;–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 lrf5h-*zua sk +; f;pnuight 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 ori*wowl mr:( h0t :z m1ys;pf5bdented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anglr:p: pw5p j9ive for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the* zamrow w/ j,(0wz6el t5g2ia light is hittingmw(te,0wgzl wrajo6 / i5a2*z the 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 maximum. 3y,;ej0pp f3x8 zzill At what angle should one of them be placed so that the intensity is subseque,f0x3zijz3l y;pl8pe ntly reduced by half?    $^{\circ}\,$

  At what angle should tha 6x p45w0nn (lthizb(unk3/ge axes of two Polaroids be placed so as to reduce the intensity of t k(n tzgbu(np63x5/ni l h0aw4he incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orienx(zx;)w s vbk7:hw( 2agbvg 9eted 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 38.0t40sxo09p /brang ym9yw)d5m c 3mm5s$^{\circ}\,$ 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 fotuytx2;sh:z ephpt2 n-w-4f9 r light coming from beneath the surface? Compare to the angle for total internal reflection, and 4p htn22wu s9fxpt-ey ;hz-t: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 throu8 i3 kjqqruhu .n0f1r2gh five successive Polaroid sheets, each of whose axis makes a jhf0q. unur2ikrq81345$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength m hv.rw0 yzkeuj1y,;-$ 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 refle804q e*adz h,p. seh+fnjf gd+cting from mountains or airplanes can interfere with the 0he, +fjz4hgda nfs d8+*p.qedirect signal 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 k)ealn(d w il8wo3.t,.e3f ocjuf15sa diffraction grating with e(ej.f3c5 aknow.fu st)i318lw,ldo$ 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 passesli b1ir,1a 3md through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown w1 ,m l1dri3iabavelength produces its second-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 broadcasts from two identical anteoh/hq b*j5k.8i9fz im nnae 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 tj m*hbi5/z8ifokqh .9he 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 outsidewycz6f72)lg fj p s3*ikgee+ 8 doorway 0.88 m wide, and blows a whistle of frequency+egk f)j* lygs2 wzf37c6i8 pe 750 Hz. Ignoring reflections, 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 r(b- eysk8l5c 7jk6hy width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a seriesgztkxy2e/;,4;ca sh n of parallel lines across them. When normally incident 460ae h4sc g;,z2/n;yk tx-nm 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 ce/khwjdif5 yu7 el0b*t so9f ;wgq9n, 4ntimeter must a grating have if there is to be no second-order spectrum for any visible wave97 hj ufww; *qo0kf45ny/e bg9s dtil,length?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by ssmq6rck; /fcnk2d9168hf* *8 givudk d6pp c a diffraction grating always overlap. What wavelengths overlap ex*8p s u6nqhf1 dd9rfcm2k6gk 68ikdc s*vpc/; actly?

  When yellow sodium ligh:liv 3zehkpocom+y1 t nw: (53t, $\lambda\;=\;$ 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 dfe2nl3tte0 r)-s)k(xlo:lwvae 5x 4 ciffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam co:erk-e s 50t lflatwv(n3x xo42cel ))nsists 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 nmgw rfpz-(ivt 3jt am:p*xz/ ;7 thickness of it, when laid on glass, is needed to reduce reflection to nearly tp3jm zti:;gx7 -(/w* avzpf rzero 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 normally on a thin s9qdf 9wd :mrd bklv7x6c/qg 18 lsl(1dheet of plastic film in air. The reflected light is a minimklsbdg rq8c1:6/(ddld1q7 v xm wl 99fum 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 fg yhyb),5:j v vg3 4wdc;t*u4)+ zyrdbki7 kldor 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 betweenud4avc xb ; 74-o.nn xu33sywi two flat glass surfacesxownu-v7 b3iunsy .34d4c x; a 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 .x s-j* . kkqdbh,x9unthrough a thin film layered on a flat piece of glass. Draw a diagram, similar tok . ,xk-hsnj9*bxu .dq 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 whe*ax g:,8m vgm8i hudo0/nk z7sn light reflecting off a smooth lake is polarized most strongly?x:g7un0 8hamz/okv* idm8 ,sg    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placeet 4-uu*hcw u,d so as to reduce the intensity of the incident unpolarized light by an -u 4,* uhweuctadditional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two pola xj+c orn9v7uhe- m95hrizer sheets whose transmission axes are at right angles. A third polarizer is placed between the firmuv5c+o rn9hhjx 7-9est two so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axeeu0, e x5pyos4s 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 irdo;p3r0zlz8*fo *his 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 lad* p;8*ohrl0 zf io3zrser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each placed at a uph-ux5qlum ( q.d6zk0y cd7djnlr )4) v 4oj-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 ,gl5 off kj1m 1am6 0gl/ztkf.$(n=1.34)$ 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 radioq+hoz+ +5 rx3s rb,jiy waves in phase with each other. They ahqsz+ 5ob yx+ 3i,+rrjre 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 az4cdwocjb b 056x039w;lvlq wavelengths, 420 nm and 650 nm, enters a silicate flint g3b65dl ww jvx4l9ccq00;oz balass 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 haqx b osvh 40s; (j12wb+u1:pz, hdwnfus one 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