Does Huygens’ principle apply t)l-cx;qp+/a. me9q ogy kp v0jo sound waves? To water waves? Explain.

What is the evidence that lighter*;ro .rsncu *6 5sdm is energy?

Why is light sometimesqa 1 c/;3xdytj described as rays and sometimes as waves?

We can hear sounds around corners, but w xz:m/t99 zge5vklrx(e cannot see around corners; yet both sound and light are waves. Explainl9r :tzm k95(zvxe/ xg the difference.

If Young’s double-slit experiment were submerged in water, c w3og:vkl (6fhow would the fringe pattern be chgcofw: k6(v l3anged?

Monochromatic red light is incident on a do4 p.hrs nh5fxi 9qur;. lm(+feuble slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would chefx.r ;fp +4. 5 hsulh(irn9mqange if the red light source is replaced by a blue light source.

Two rays of light frombm, b9 7 grdqg(6iy)bd the same source destructively interfere if their path lengths differ by hobr iqy 7md6)(9dbg ,bgw much?

Why was the observation of t:7 rjeacvud2lfka38,b64mu v he double-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffrua4d6clvbfauk3 re m ,2v8j 7:action?

Compare a double-slit experiment for sound waves to th da.a9:ho6.;k m (i-pgqwan imat for light waves. Discuss the similarities ak;p.mg diaia9 o:6n.-wha(mq nd differences.

Why doesn’t the light from the two headlights of avrvb2 f /)sz as7ti.9a distant car produce an interference pat9 f)b2svtiz7/. rsa avtern?

Suppose white light falls on the two slits of Fiup: :qro7zq5fg. 24–7, but one slit is covered by r:z7uqo fp5q: a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light pas:gmd6 ; 8zg mb9u:fcikses through a flat piece of window glass, it is not broken down into colors as it is by a prism. k mcdg;bz:96m g8if: uExplain.

For both converging and diverging lenses, discuss z +yx6j.drx d6how the focal length for red light differs from that for violet lighr 6+ yjxx.zd6dt.

A ray of light is refracted through three different materials (Fig.i/73o. cr aanu 24–55). Rank the materials according to their indeara 7oi u3n./cx of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant ligh d.ny ycf+bi) j-0x8mmt source through a narrow slit between two fingers. (Adjust your fndyy 0jmf8-ci m .x)b+ingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole apparatvk - c4)boqeh+us is immersed in (a) watk q+)ch-ov be4er, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is 4k0f5 p9f rhoothe effect of increasing (a) the slit width, and (b) the wa5h pofof0r9k4velength?

What is the differenr8-go( +9m54fi0he 3xzytwwpua +8 dkf(gnzsce in the interference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction gratih0 fa 2q)u2p ylkxe1upx9-.jzng, what is the advantage of (a) many slits, (b) closely .kp2u f)hx- 1zqpla 09y2 eujxspaced slits?

White light strikes (a) a m1 h ;oh)sjrdrwa 5p1;diffraction grating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident be;hjo;msha1 dr) 5pw1r am 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 ; a)z*ti9y zk 1+gjmf.n n-ptnnm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spet jp1z*ti .-nykman)+;z9f ngctrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a soap bubbqyr,uf:5l0aat -is26y yv9uw le and not for a thtivw5ylaquy a2 f9s0,ur:y6-ick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the re1g huz9 qus9y:uf7rs a/7zqf7flected light is a full spectrum (Fizqzqf7sa7 7/ yh urf9s1guu9:g. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together ff/ma3qhrnf77+ q r )puarther from the center?

Some coated lenses appear greenish yellow when seen by reflectep2/a7qqpy; vyd light. What wavelengths do you suppose the coating is designed to transmit com q q7pa;y/vpy2pletely?

A drop of oil on a pond appears bright at its edges, wherehe8d-4j7o(idyw xtqc, *vf 1s its thickness is much less than the wavelengths of visible light. What can iwsq(h-7yj,vd1* f t8 4c deoxyou say about the index of refraction of the oil?

What does polarization tell us about the nazl2 , vxhra 9ih2eg)of*fm1z2ture of light?

Explain the advantage of polarized sunglasseyuyw7 xb(*g z*j1v 5qd v7.oses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polari5al.v cof6 6jtzing or not?

Two polarized sheets rovt hb--7 jzzk3qc+t 54zgi,kptated at 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 esefn-)n-k(c if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it isb3o6ga6v h p44 m,ay/dk mu-gc, would sunlight still be white, or would ibaha /m44,uc mo vg6-ypgk3d6 t be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-oeb( gg+ld8ui9 :rk,akrder fringe at an 8gik,g(u: b8re+ldk9 a.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 angq63vqgx o2m5qedw:-qb33o- hnt w uo ;le 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. Successi7624 )f0ujn 1z xoga/)q1xouob dtgabve fringes on a screen 5.00)0ugoj7d2b o qxax61btf) /g1a4znou 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,lhmpjqu 6-j ogrq: x-e+2;o)d with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fri-u joq g+jhplox6dq-e:m)r ; 2nges in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm fallcj):vibmc:5 u s on two slits and produces an interference pattern in whic c)c :bj5um:vih the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.5/cktj9s,( smz 8 mm apart, how far apart are tc sjm9,/sz kt(he 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 9h+ l bdcg)8vq trh:-qgives a second-order maximum at a cerrhbc) :gvh-8d+lq qt 9tain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallpwnfe.pa :xcmk)+33in 3b r-t el crests 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the bx+w n3b tp)ain-m:f33kr e .cpoard, at what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass i y)rgvy.3ccw69/gl9 je nawi,s placed in front of the lower slit in Fig. 24–7 so that the two wa yyng r jgcl,evc9)3w69a/wi.ves 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 expn4aus kg o0:-r 7;qdtaeriment, the third-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the cena d; 4-k0s: u7gatorqntral bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm g;n0y7wjsfck u8 1g nudx0v;- are illuminated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m fron-kyjun 0 c;s;uf g70vd81xgwm the slits.    mm

  Light of wavelength 480 0a 1.2 f wlheu9qbgkmew/6qr9 nm in air 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 double-s253/ 9ss g+l tswxcctalit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (min3cl/9 25swta+sg xcstimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed tha8(gd nx iz)7x xad9j1ft of violet light (400 nm) in silicate flint9z7fi j1xn 8xx)(agdd glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60.00 4(*mjl4: zoeb 7najig$^{\circ}\,$ 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 wavelendpe:au *qb6d 6gths, $\lambda_1\;=\;450\;nm$ 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 0.044+*lj xbzzguw19 (-ndn0 mm wide, what is the full angular width of the cn(+ uxgzwl9*-d z1bnj entral diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that isd0hk pzv9f4h: $ 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 k63 wxn s; mpj3aq*p4ofalls 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 p,x1;r 23b9jdottho d-nm light. What is the width of the central maximum (in cm) in the x, ;bpd31do 2jr tt9ohdiffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelengt /- +.p,w zvwz2yuszwfh 653 nm falls on a slit. If the angle between the first brightwp2z.vu+wz/,wz y sf - 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 2.30 m behind a 0.0343f8axw6qa e1 oub4ay(jsl75n8-mm-wide slit illuminated by 589-43 awus b1ofjae q6anx(5y8l7nm light?    cm

  When blue light of wavelength 440 5ja p*op* mxk.g nyc,f24kk u6nm falls on a single slit, the first dark bands on eithej2pk.5ok,c 4*xaun6fyk mp*g r 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 falls on a single slit, it creates a cc1g q, ymrrl0)f4yuybc5p2/ k entral diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. Howfgr/c yluy )0r,cy5 pk2 b1q4m wide is the slit?    mm

  If a slit diffracts 6vf,h7k.vn7a y 8ge9lwxu7ox -p6 5xnz/xi8fa50-nm light so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be 9wx7 a6,7v i/xfx8a.g- hyvuznxf5okp n 7e8lthe width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelenginkq,n;wl v7rq6x (x3(o:4 czdix9eith $\lambda$, 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 max0eq(4 c:ycpj/s7vy dlimum when falling on apjc4 /s0( yqe7:ylcvd grating whose slits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a grating have if the third-order okzv+fnk -ee 02-9s7)ofw t rooccurs at an 1rv+7etn 2-f0) -kekzo9foows 8.0$^{\circ}\,$ 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 obser14q qqmu4owo .xb x ax -.0vap0v*rq5uved at x xq1.qo-5qpbm0ro4uq0x a4va *vwu.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 67d:mnql -y eas0rfa- 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 a cxmjwe 7:iq*mcz3l te1 0t u/-$9700-line/cm$ 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 grao q tm:g/193 rzwad*zpting with 6000 lines per cm is illuminatew*m3d g rq1ap/ tzo9:zd with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of2 dai+ly)j-c.zh9z6xr) zks l the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per c)9 + hdr.k zs-6z2clli)xjyazm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths fro:sl(kjeoih9l -2dh4 0 ijo;/r (ulhjam 410 nm to 750 nm falls on a grating with:( 2a lh uhi(0hkrj/di9e o-sl; 4lojj $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which proy 3 olf-pzk8k :hldobqg: -lpzn)g*1 *duces 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 lilbb-f5j vuugj9g46 r 6nes 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 wav-n z4o 4pdenu qf0i4f4elength is most strongly reflected at the center of the outer surface when illuminated normally by white light? As0uz f4f4-np4qeino d 4sume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes its; vku8 5gld2 fgdbh *e,b/0zn Example 24–8 if the glass plates are each 26.5 cm lod,; e/bzfglh udvbs5t 80k*2gng?    cm

  What is the smallest thickness of a soapdq)qh62o fl m. 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 yellow rg dz7,.mjii oy(epg nj* 1.)l- uyfp+($\lambda\;=\;570\;mm$ 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 the dar;9vnpr+77gvc r hgh z1k spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 24–vn 7grv+1rpz7h9 hg c;31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of .vd2w,xw vrw1two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (wi vd1.ww v,2rwxth one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should th6 b)2g:yu1tukc sj f4ye air layer be between two flat glass surfaces if the glass ty 4 1)u2:kcgjuybf6sis to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspdlczi))) )p 9ila79tde7g ykx ected 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 alcoho-hriro*qj3 4wwy0v f8 l $(n=1.36)$ 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 liquid, the diml1 so(hk)xktha*6z)-ao: 0 vr/su crameter of the eighth dark ring decret/ a v)-(6mhrc)kho1 0*ss xokra:lzu ases 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 interf wmkwq6y,b rp z+p-3)+te dqu;erometer if 644 bright fri6kwz dw p rp b,u)+3+;y-meqqtnges are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interfr n o av.;gz;/-p6uhumerometer. 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 wavn;gau/ p hz6-uov;r m.elength of light used is 589 nm.    $\mu m$

  How far must the mirror 7fa5tdx gw2r4gz9 0lxxflk z6:f( t7z$M_1$ 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. 24–5 3li603rs, zyn ri2wd(n0bdlx 9) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is a02ni(r3, l63dwsbdnxz0ryl illowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at)2y:0vdiyz-uer73c l , fk;t1ft)n rh bi(xsl 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–g cu a8p4ls(f,blass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diawllu4 w3uwsqjjp ;h*se f2 :mu:7 *fwzm4) l)amond submerged in water if the light is hitting the diamou)ffl7:msm ; w3u u4p:aw4 **l jzwse)j w2qhlnd $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing throughax g4899ze c og1*e crprscct 7.n3q:y them is a maximum. At what angle should one onp9csrrg oy:8ce37.4xtec 9aczg1* q f them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should thel le* 8/w3wlx ocbkclnn58:f9 axes of two Polaroids be placed so as to reduce the intensity of the incidentn8lel * x3lcbwfwn o lck5:89/ unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriveb2 eyw tkfz:75ku +y gru/.6ented 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 38.0g)k yer66n )iiiof j77 k99jmu$^{\circ}\,$ 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 surfacni ,0,m8itjgwhdm5s/z 8y+epe of water for light coming tjz ph08wd my/,eg m,5+ ins8ifrom 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 succesv-k ,:rrc49+nef,n 1bcp abnlsive Polaroid sheets, each of whose ackevnfrpann -1+l4c:b b ,r,9xis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength ean4+ u; e ddhh1l+7 phivg,l2$ 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 i *o5-v8x rp9 gku-h;:ictrpvmountains or airplanes can interfere with the direct signal from the stai5hc: -9g turvp-*kx;o pvri8tion.
(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 passe w942mdo)xn 8gjg) dwps through a diffraction grating with p4nw)ddgxg 8m9o 2j )w$ 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 twou y7i ld)g2v+si;t k3x 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+uvliygi 7;3s2) tkxd 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 antennae atbf4zl -gw v.s/ the same elevation bzg.4-w/vlf sb ut separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back b5s5i)zqx hm nt c /270qlkp7szul3m7from an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at wzhms0/2)kn7t 7 c5s3lubxzpml5q i 7qhat 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 fa/lt fr(t.ax j(kfv 0z;lls 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 a series of parallel lines across them. Whena;4bqwr.mqh +b6oze 8 normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an anglbam8 . rqwobq+ ;z4h6ee of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeovu(4e6ay (b wter must a grating have if there is to be no second-order spectrum for any b4wo ey (a6u(vvisible wavelength?   $ lines/cm$

Show that the second- and third-orrzl.28djb8-durb jlpl57 mw1 der spectra of white light produced by a diffraction grating always overlap. What wavelebwjudjpl8l z5m-d1 2r.bl87r ngths overlap exactly?

  When yellow sodium lid 0zv*u0 +mickeb(3:rnh hxi2ght, $\lambda\;=\;$ 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 theyu 7490b r;gs yglj2pw pattern is viewed on a screen 2y2r904w7bjlsy; g gu p.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 materialjctrs ), 5hbe x,d 6sfq z8qft*.6eq9x if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of s srxq.,qf5b)xe j68eh 6f,dct *ztq9600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of (d7bl j6je4mqr 5nk3a variable wavelength is incident normally on a thin sheet o5nj3laq krme4bd 76 (jf plastic 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 needed for an anti-reflective coav*ev tgt006lh ting $(n=1.38)$ 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 aiwo2ld */z1gbf r layer between two flat glass surfaces if the glass is to appear dark when 640-nm light is incident nog*f ldbz1 /ow2rmally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layered on a flat pxf,*j6v u- whqiece of glass. Draw a dix6-jfwu ,hq* vagram, 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 light reflecting off a smo+qfak-:ve 7r foth lake is polarized most stroqf7+e fvra:-kngly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to redm5-fos 31q cznh;4ol dm5qr2 suce the intensity of the incident unpolarized light by an additional2 on1qolcs 5z h-m3sm 5rq4df; 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 arehw-lw vl8hp4) jo)jn,a7 *bt8r b(ou w at right angles. A third polarizer is placed between the first two so that its ah*vj,wt-loa8 l wrh(bwu)npb)o4 j 87xis 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 the,hd-5+ e ca1aha-swomydau 6- ir 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 pointed at the M+v+nyv q5c )dloon, 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 laser). Estimate the wi+nvdql5v+c)y dth of the beam when it reaches the Moon.    km

  A series of polarizers are each pw6 r /q:nhgp)vlaced 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 6tjq0pu il*f7$(n=1.34)$ 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 phaseii,kz / 6)-(trakergc with each other. They are located at points(g-a t/k ,crie)6 irzk $S_1$ and $S_2$, separated by a distance $d\;=\;175m$, Fig. 24–61. What are the first three points on the y axis where there will be destructive interference? (Destructive interference in this case means that a radio receiver placed at that point would pick up no signal).    m    m    m

  A parallel beam of light containing two wavelengths, 420 xg-5np:upq h( nm and 650 nm, enters a s:hug-nq (5 pxpilicate 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 flat surfz hmp5b1xm.2pace 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