Does Huygens’ principle apply to sound waves? To waterrf2 3tr/jg4 zzh(b4 og waves? Explain.

What is the evidence / +vre3gcg/wq that light is energy?

Why is light sometimes described as rays and sometimes as wav pp-kz;kbt-h2nh ,(l mes?

We can hear sounds around corners, but we d+i jhgcjv sxn,4mw(3 / 2d,s7ila9fjcannot see around corners; yet both sound and light are wavehd/ g n9i(j2sfc7 ,ls4d wv,xi 3jmja+s. Explain the difference.

If Young’s double-slit experimenlomekp ; p7a5x)a*u; kt were submerged in water, how would the fringe patterpalpk e 7; ;5x)uo*akmn be changed?

Monochromatic red light is incident on a double slit, and theo 8(*9buidq ajivs85c0wor q* interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light soua d*si9bo v*jc 5uo(qqrw8i80rce is replaced by a blue light source.

Two rays of light from the same sourcgh 0am(snc88iw bgh5f25ii;: o6ijp we destructively interfere if their path lengths differ by how m6nimai8 ghjfw c ib ig:85 0o(h2;s5pwuch?

Why was the observatiojx(4 npwh3 m,jn of the double-slit interference pattern more convincing evijjx,p3n (w4hmdence for the wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for ligh+q1etzl ;j( y 6gj9mmrt waves. Discuss the similarities and;mtrj m91+ez gyjql6( differences.

Why doesn’t the light from the two headlights of a distant cd, bkh(3i2u 5nr(j eshar produce an interference pa,d2 (h ru3sikb(n5hje ttern?

Suppose white light falls on the two slits of *,/vsrt4g -zng;ist g Fig. 24–7, but one slit is covered by a red filter (700 nm) a ,gnz/ st;sg-*tigv 4rnd the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glasau(e ug.4 n 4c9+unzxos, it is not broken down into colors asa+ z.9ng4 o neux4(cuu it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length rt9:4eb i4jh2 qhcsj:for red light differs from that for violet scq9h 4j j: hit:reb42light.

A ray of light is refracted through three difi ijnijyn:d 8s;tw1 0a/)ciw6 ferent materials (Fig. 24–55). Rank the materials accordii s dnyaw/inwj1 6j80it:;ci)ng to their index of refraction, least to greatest.

Hold one hand close to your ey kawtjwwg6(de0f s8-1e and focus on a distant light source through a narrow slit between two fingers. (Adjust yo6fw(dg a8wtjw 01s -ekur fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole 2 ub,w-n9 y -tfbql(xjapparatus is im-9-b u tlfnw2q,ybj(xmersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effe-s2 .ekktf/ et em59ixct of increasing (a) the slit width, and (b) tf/sm9e etx-k.e 2it5k he wavelength?

What is the difference in the interference patterns formed (a) by tws spagbofl9r.q (81 t1o slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, (cqp;acnb/ 3i y d,,m ri6iu8lwhat is the advantage of (a) many slits, (b) closely spaced 3i im ,,ul cidbr qcy;68anp/(slits?

White light strikes (a) a diffraction grating, and (b) a pris rq)sm2hy/6- ;oqkw-tmzx.r ;o ktlp6m. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of tsq-.o2 t/kkw 6l)hp;z qrx; t6ymo-mrhe top of the rainbow in each case? Explain.

For light consisting of wavelengths bet6y 6j*ceh4fipween 400 nm and 700 nm, incident normally on a diffraction gratinj4fi6yc6hpe* g, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes not2qx/w/ g9pbm ,t1 wbym,t-vjhiceable only for a thin film like a soap bubble aqw9 pb,ytm gw jt2/hx1v-b,m/nd not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, vg*ayoi:r 7nm)/ jcdn(q .z)qthe reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect t.az* )/(g)q incqnmrod:7yjvo see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the cent -nho 8lyhp,v9er?

Some coated lenses appear greenish9gg9is ifg38y p 9re,k yellow when seen by reflected light. What wavelengths do you suppose the coatin i3gi9rk,8gyp fsg9 e9g is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, w jc-f8kzqf0sfd,8,2a5y qyt ohere its thickness is much lessf8yf q8-oa q,2tyzsc kdj,f 50 than the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us ab 6 ,n+ieb g06rbnlk(hqout the nature of light?

Explain the advantage of polarized sunglasses over9z 1 err2br3vr normal tinted sunglasses.

How can you tell if a pair of sunglasses is f7 zpfrrc2 1q e2ok6h,polarizing or not?

Two polarized sheets rotated at an angle of 90g ac+q1t6p :i)nui h+u$^{\circ}\,$ 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 n*/)wq ux-c ec m k3mw/zmqnk4:35eu xif the Earth had no atmosphere?

If the Earth’s atmosphere were 50 t) so npqn* pwv)r(nekt;2z *;/5y( gkgsx*iuwimes denser than it is, would sunlight still be white, or would it be some other color?ngt(;qs(wi*) / pnrkws n5*) uxk;e2*ogvpyz

  Monochromatic light falling on two slits 0.016 mm 0 qk+fxo75a,1.scda6ud*igbe p-auc apart produces the fifth-order fringe at an 8.80fpuq1 g aac6*kusi dcdaxo5+ e,-7.b$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm90 xsfrza1rj. 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. Sucvjt m6cg:93r -m2x quncessive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency692ut:3rjmcnqmvxg- of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a waveleng-2vu .bt+1ldxydia/cth 656 nm, falls on two very narrow slits 0.060 mm tlc1-/2x udy.d v+aibapart. How far 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 two slits and produces an interf4 9 c6q6uyjlimqp89f gerence pattern in which the four qg6998i4pm f y6qljucth-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 lim ko*;tuvedrm-6 kh95ght passes through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen k5 uh-kmte6 ro*d v9m;1.0 m away?    mm

  In a double-slit experiment, it is found that blue lightz9*vwamzo d1 fvhh)ubwp/;l)me- z /: of wavelength 460 nm gives a second-order maximu*h; f a p9dv/mm 1zvzewu:-o )/wbhz)lm 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.uv5mg6 x)d+d x y:lbm)rkg(0g 5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond thegyg 0gdx5d+( mrx blk mv):6)u 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 qf.:kd4 s 3 wgp)hpdxafq:, a-front of the lower slit in Fig. 24–7 so thatk f: xs3gp f-.d:,qpq4h)awda the 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, the third-order ma)k.iwva -(xltw3x(r 6 yf2xy wdbt(r2ximum 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 fr)(xi2w-.v2y(w frwt3( yladkt xr6xb om 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 544 nm light. F qz, p)/pkisa,ind the distance between adjacent bright fringes on aps,aipz k,/)q screen 5.0 m from the slits.    mm

  Light of wavelength 48r(zn0 kpt;bdgq fl fisfg(/(75zn67 h 0 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 (yd. b+z zzd5wyv4m 7p5n=1.60) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (mby dy54d.zzmvpw7 +z5 inimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red lig2e ;9rmxq u:zy co/3oeht (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (Sezu2 /xe; eo 3r9:yqocme Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60 v/7 1bb*udlbq.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 contai h 3lcr423ymew u8ry5ening 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 ioouwkij40de86od(: o s the full angular width of the central diffraction (oo8 0d6:j dewkuo4oi peak?    $^{\circ}\,$

  Monochromatic light falls on a i: crozeemwxt5 2t9+3 slit that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength 520 nm falls on a sli0w f k+s*2(n4 xpsqr,k7fgfhwt 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 wid7pv k*)kpdg,3 zvr x,ve is illuminated by 450-nm light. What is the width of the central maximum (in cm) in the diffpvgr*v ,vd z3) 7pkk,xraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelj+y )y2q6 smdpength 653 nm falls on a slit. If the angle between the+y )pqy6msjd 2 first bright fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m be-4 i6pcqhf ql(hind a 0.0348-mm-w64 fcq ql(ph-iide slit illuminated by 589-nm light?    cm

  When blue light of wavr(kjc 1 g63hcn1t dzin4 ;tlw8elength 440 nm falls on a single slit, the first dark bands on either side of center are separ k;tlnjdczr n3t1w i c86(h1g4ated 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 h4 8ygq wad9w-a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m awy8w4q9-da w hgay. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum is 4.0 c xz,9z0*uo i-cvfn;p fm wide v fxpi*z ;zu of9,n-0con a screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength :ng0jk (-t lu63j7:k 1tlsz a6beisve$\lambda$, 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 maximum wkkb2q ei: c24uhen falling on a graeub2i4qk k2: cting 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 gratingc+ uxg 5.fbed2 have if the third-order occurs at an 18.0 bgcf+52.ue xd$^{\circ}\,$ 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 5 x*u+tewiq :)t;( wggi89-nm light falling on a diffraction grating is observed attq w;exw:ig+g t)(i* u 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 cpuf;c .+gl2jgv1 ac3i.0 gqh$ 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 e/s,c 11r ,rurleq g wl*8xd4j 7,mfyo$9700-line/cm$ 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 n/a6b5zt -m 6ytt5rh gexye3/order that can be seen if a grating with 6000 lines per cm is illumey-t5/am 6xtrbn5/zyh t g6 e3inated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral o igo4i;m9.-aym ,jfq(02vzgb9h iqz-t ga zg0rders can be seen on either side of the central maximum when white light is sent through a diffraction grating. Whatv4gtma 9gb.zoqziaj gf0 - q2;9hgz0y(,- mii is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavel6ripfm-/dw,vt )-j3jk a + w;dd:k druengths from 410 nm to 750 nm falls on a grating with r :dj,a3-div m)ud-fj ; tkwpr6dk /w+$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light of a kni7j4raf30) -my9cds6r z9 lnw3zdwdzown 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 measured by y 2:j )(cl+oe+j/ t2znaktvul 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 wavele.gr(:ugvv9lc kym6; gngth is most strongly reflected at the center of the outer surface when illuminated normally by whgmcguvvry(l 9 ;k.: 6gite light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass plates-xx xci6j u:*.yevt+f are each 2x*y.ej xx6tc:ivu f-+6.5 cm long?    cm

  What is the smallest7g7 /v,veoz(/mwa vi y thickness 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 yellow n elp9,,1 nzix($\lambda\;=\;570\;mm$ 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 ringsfjqy7 g/n(5i ,9be pfh (not counting the dark spot at the center) are observed when 550-nm light falls n97fj/f5qgb(,phne y iormally on a planoconvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically fla 4;1c bndb- n1ffmww p4r2t+tvt glass, as in Fig. 24–33. When light of wavel-ffb4 tn+n4dv1t rwb c1m w2p;ength 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 clvomz:l 01f;yhw7x*a:w/ t ltwo flat glass surfaces if the glasmt: 10xw hll yo:7/flw*c;vz as is to 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 a stolen diad lbvxbf 5qn4/n cr(0v(- y6ljmond $(n=2.42)$ 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 alcohozt20qa1 t (.n;uip+vn6 rql;pm igb.il $(n=1.36)$ 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 liq p/hd2kv,7zqn8r s9utuid, the diameter of the usdz8ntkqpr /97 v2,heighth 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 kze7rhjx3d3lsp:-s b4 h vs6 *interferometer if 644 bright fringes are counted whk s3d-: sr6blsh37 v4jzxh e*pen the movable mirror moves 0.225 mm?    nm

  A micrometer is connected tomx(9f/5y 6sgeic7tv y the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of brighty(7sgvf e96xt5yc im / 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 mirr4xo8 ,csp6pieor $M_1$ 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.2lw:cjc8h*)ib/*eby 8bqp fd 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 past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming teq8 hflyiwp) *c8jb2dbb: c* /hat the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at -*7,slrjw jvf 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–glass cw 1v*eufrvtb,. .hi9$(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submergeeb)e7x fhuu: 9d in water if the light is hitting fheu9u e7b: )xthe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light g lj63w8;y,ddhv9xxn passing through them is a maximum. At what angle should one of them be pla86xvhj3 d,;d y9glx wnced so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed s49 w.bvzch,tnrpi,.mo as to reduce the intensity of the incident,tbph., c mr.zv 94nwi unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at oz ,k j;;s.zi(q.djyz di+ 2e3ik0nwx40$^{\circ}\,$ 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 2suhaw5 rlx;+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;(z ei xptarr6vc(16lypv2(t the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflectilpzi(ar cx6p;6 e(r1tvt vy (2on, and to Brewster’s angle from above the surface.
If the light is coming from water to air, $\theta_{p}$    $^{\circ}\,$For the refraction at the critical angle from water to air $\theta_c$   $^{\circ}$ If the light is coming from air to water $\theta_p'$   $^{\circ}$

  Unpolarized light passes through five successive Polaroid sheets, each of who9:x (0ogy. tq ext tene/y.sz5se axis makes a 4:x0q tz e.ne/9 .oyxe5t ty(gs5$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength hw,pv mw f)4fng2w:r 6fvtkk7ne 99. t$ 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 refgmna9f4 (w rl02t e-ejlecting from mountains or airplanes can interfere with the direct signal fro-ler4m t a92wnje( 0gfm 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 diffra8i0ql8ug6e)va /eh)k- xq ntgction grating with gxt/kn0e)6e l-ai)qgu 8hqv8 $ 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 thanon(ro5kno r93.*u grough two narrow slits 0.60 mm apart. The screen is 1.70 m a.( 5uoo3k grnarnn*o9way. 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 wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from tlbm( ylb r3kkf 26n* e7z8le*czzk2n+ wo identical antennae at the same elevation but separated by an 8.0-m horizontal distance fb6mk(32clle*kr2z+nly bk 8n z7*ez 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 from an out67o f,:m dyfvvside 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 the whistle clearly onm76of vyd,v: f the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit nyo:rf8cl 9e1 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 acfph)9jbhv( 686njxp gross them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an angleh9( gbp8v6f xj 6pnjh) of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have )o qiz/ q7(uey oi0ek*if there is to be no second-order spectrum for any visible w)7yoik e/oei (u*qzq0 avelength?   $ lines/cm$

Show that the second- and thirdodhx1u ,wq ue0lf e8+3ff +8ns-order spectra of white light produced by a diffraction grating always overlap. Whaf 08f+8 nuq+h3e 1slwedx u,oft wavelengths overlap exactly?

  When yellow sodium ligr*)rug ,x zwl(ht, $\lambda\;=\;$ 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 witzz+qt)z )9amu h and the pattern is viewed on a screen 2.5 m from thezu) 9zza+)qtm 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 u.o 0j,dc sx nb5y/3axthickness of it, when laid on glass, is needed so,0x5y.jd c ab unx/3to reduce reflection to nearly zero 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 ap52 thjucx6 n/ fu02nk thin sheet of plastic6n 5tc p/hufj uk022nx 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 fre/ynp4m4qym ak 803anti-reflective coating $(n=1.38)$ applied to a glass lens in order to eliminate
(a) blue (450 nm),    nm
(b) red (700 nm) reflections for light at normal incidence.    nm

  What is the minimum (non-zero) thickness for the air layer between two flat glaiwpk88-au0*hd 1 hd se.zfc 1iss surfaces if the glass is to appear dark when 640-nm light is incident nkehhd1da0uc zi*1sp-wi88. formally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted 05d 8h mwi+kb)wd:w3,dhb.w+d xuv ogthrough a thin film layered on 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. Di+bk dug+dm dw.hiwd0:5ww hxo38bv ,)scuss 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 liiiu,xh 3op:j(c qhl33ght reflecting off a smooth lake is polarized most strongl ixiqh3,3:uocl hpj 3(y?    $^{\circ}\,$

  At what angle should the axes of two Polaroidss oj3 0bii -r1/optb7x be placed so as to reduce the intensity of the incident unpolarized light by s3b 0x-o o/ 1b7ptjriian 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 rjgokhx68fx9 ltk 9;2 whose transmission axes are at right angles. A third polarizer is placed between h6lx k jo2k;ft9rg x89the first two so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in ,qoi:s gjd +/gsuccession with their axes vertical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 1.0 cm and i,ovsvvu1ft 02pq)/l cs pointed at the Moon, which is approximately 380,000 km from the Earth. Assusv qv)12p0c t lv,ou/fme the laser emits 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 10t -r dlpmbwf+l+-5+ i+th a: p7pndvr;$^{\circ}\,$ 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 1 hv4.viqth8pk5rv q;$(n=1.34)$ 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 antennasx6eq2j-f3yc s radiating 6.0-MHz radio waves in phase with each other. They are locateq63e x-y fjsc2d 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 wavele4iv 8g mmh/k2engths, 420 nm and 650 nm, enters a sg/ k4 viem2mh8ilicate 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 so dh2 ,pvgga8)urface 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