Does Huygens’ principle apply to sound waves? To o aj*1hn lh9*na )zl3lwater waves? Explain.

What is the evidence that lighwom r9ugx7:n4g/2uk kt is energy?

Why is light sometimes described as rays7gn3ut * x9(jquofcp/ and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet buvdl-k s6; ;of2u f;aioth sound and light are waves. Explain the differenc f isv ;uld-fa;2;o6kue.

If Young’s double-slit experimeg:hy4.x yk8-cgt+as ant were submerged in water, how would the fringe pattern ay4-.c+x gs : ythakg8be changed?

Monochromatic red light is iu)1ytl/x(lw*(, brc s wj4 goincident on a double slit, and the interference pattern is viewed on a screen some distance aww xt(glu, rioc( /wy) 1bs*jl4ay. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if their 9ssv gw1mc 1u3path length13c9mws usgv 1s differ by how much?

Why was the observatiwi,g2-.fdpnu qw2 05vuj fy5ion of the double-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffractioujqp,-2 wi05nvfy g5 2.w uidfn?

Compare a double-slit experiment for sound waves to that for light waves* *- si7m7bxs2fw altc. Discuss the similarities and differences7bf*2icss *tl amw7x- .

Why doesn’t the light from the two headlights of a d5gh.svsi e1u t 45 c+plfd 3d18v:huugistant car produce an interference pattdv 5+edui fv hluup 1hs814tsgg:35.cern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit z0 -9gi ddj9ftis covered by a red df 9z9gj-0it dfilter (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 of windotpc7s8ms e.s(*.v (.m 3e gl(lp tknoqw glass, it is not broken down into colors as it is by a prism. Explainc tq ep.(7m3s(.tno*vmpl.ksl 8se(g.

For both converging and diverging lensesn4cqu,gq i 1w0, discuss how the focal length for red light differs from that for viol0q4qcg wni1,u et light.

A ray of light is rei;l.6v uu 41c+pqdauuncz j 5(fracted through three different materials (Fig. 24–55). Rank the materials according to th+jc.u vc 5uau 1ld64qniz(pu;eir index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light rxief1+8 r2d 7d d o1h.6tbfigsource through a narrow slit between two fingers. (Adjust your fingers to o1if.ro8f htrd d 7d62e1i g+bxbtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pat.6dam 2w4jyyz:b:ts k tern of a single slit if the whole apparatus is immersed in (a) water, (b) a vacuum, instead of in::dma42.bs6t jkzw yy air.

For diffraction by a single slit, what is ;h:qlj 4 ..n oo96jnggrruf0o the effect of increasing (a) the slit width,4 fgoo6 hjqj0 nn.r9;r.:goul and (b) the wavelength?

What is the difference in the in 5fkzvzgjl (+ 3ve:2ofterference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (a) many sliy x*qkp4 s(m 8gpxxj*-ts, (b) closely s(* pyqks4-g jxxm 8*xppaced slits?

White light strikes (a) a diffraction grating, and (b) a prism. Ax6g4e9 uaqflp312 m iil*pa2e rainbow appears on a wall just below the direction of t p6l2me2uqagx1p 4l3 fe9i i*ahe 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 aaro-a l+e:5m2rt g e9xnd 700 nm, incident normally on a diffraction grating, for what orders (if any) wo2lm :a-rtoeag rx+95euld there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin 5l2dmn auw21zw*vb;i film like a soap bubble ai5;*1zl2 wwvu2dmn b and not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, therjs 91j , exa2wtlv. ul*7-xmq reflected light is a full s7-1jt 29qasxm lxur,.wjle v*pectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (am-ln82* yhpd cnrw6 pf4 5yp5Fig. 24–31) closer together farther from the center?

Some coated lenses appear gremj0osl. *l / 3zsyktq4enish yellow when seen by reflected light. What wavelengths do you suppos0l.loz sj / s3kq4ty*me the coating is designed to transmit completely?

A drop of oil on a p o(o 7g-sks/ya,c qw+za75qm gond appears bright at its edges, where its thickness is much less tqw/s,-7g( sa cmzq7a+yokgo5han the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell ussol 99 .l m.9unemh(hh about the nature of light?

Explain the advantage of polarized sunglasses over normoi bb(( hi:+tzi53 yuhd cf(q0al tinted sunglasses.

How can you tell if a pair of sunglasses is polarizing or not?c,dpf *(s/c-kx7e2flcm m b4tm hy 0q5

Two polarized sheets rotated at an angle of 9 d95siq dwg1/b)yir0y0$^{\circ}\,$ with respect to each other will not let any light through. Three polarized sheets, each rotated at an angle of 45$^{\circ}\,$ with respect to each other, will let some light through. What will happen to unpolarized light if you align four polarized sheets, each rotated at an angle of 30$^{\circ}\,$ with respect to the one in front of it?

What would be the color of the sky if the Earth had nocc./f*// 4e .xpuzdnv dao:+ cwoq n5o atmosphere?

If the Earth’s atmosphere wepgl8 bbk s4,.ayj)) ggre 50 times denser than it is, would sunlight still be8js.4by) b)ag, pkgl g white, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart prod ;r ) t4,n(d,g (p;gzlqllmn;je* fix3gny st5uces the fifth-order fringe at an 8.xtg;lsl *, ,rjtngz5ym34dn q(fe lgn();ip;8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed *0x-5rhezmdis2xu: sat 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 slig7yz9(kv poja 6s4x n5ts 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength anjy5zag x6vs 79(4 nopkd frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne q oh71.hu:ntplaser, with a wavelength 656 nm, falls on two very narrow slits7n po1:htuqh . 0.060 mm apart. 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 f,)t (7mevp (x1ijbk)hqry*czalls on two slits and produces an interference pattern in which the fourth-order frit, 1 7qphcy* (ve)zxbmr(j ki)nge 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 pck:u2 vbbs1hg a( g-1passes through two slits 0.58 mm apart, how far apart are the sh-g2( s1a1pbk:vc g buecond-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue lightovcr.0 p4 (ohz of wavelength 460 nm gives a second-order maximu04z co.or(hv pm 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 pav7tiii2gllau(lkh87-(0a1i yr i ,abss through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative tol i8ak u- th2iayl0ivbg 7,ri(l(a1i7 the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower 9 *bp6ybjit-hslit in Fig. 24–7 so that the two waves enter thb-6hi pb 9*yjte 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 maximuh 5cqzd 2xn 0az2)x,tom for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the )z ,zntxac252x hq0doslits. 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 are illuminated by 544 nnbz ;axl;,,jo nqv8-4darp3 jm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the slits8ndpjv,rx anl z; ;j,43ba-q o.    mm

  Light of wavelength 480 nm in air falls o )myswb)e/l7cslk62rqsbf4g + ,lb1i n 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 plaxlehuv/0g/24 8x3s.dyiq n;gqg(j t nstic (n=1.60) covers one slit of a double-slit apparatus illuminateuqg dnt .024gsj( 3nx ;v/ix8e /glyqhd by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of rjzuoq p/ em/)fnyj551ed light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See F oq /uzy)j5pne/51jmf ig. 24–14.)    %

  A light beam strikes a piece of glass at a h)5kxiv /v-g*g:5u3 lbls vem60.00$^{\circ}\,$ 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 containij 3 pgal3tdw4h f03b*bng 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 oa +ssyqkb.eyi6+l 93gn a slit 0.0440 mm wide, what is the full angular width of the central diffractio y+l6sise 3ga 9kq.b+yn peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that i,v.d zt7;vztr dlx/+es $ 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 thaf/w9tiytf 6a )t 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 t;av**th-quavxdz*3 pvuhxp*q :fef *1(*wt illuminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern ovth p v1*uzxa*v*uf*;3*qettwp :-*fa(hdxq n a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If th.u 9ildo y(sv(zsy o86e angle between the first br.(vzu89 d syioyo(l 6sight 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 k0(z3wr :prwif /dr)m 2.30 m behind a 0.0348-mm-wide slit illuminated by 58):zrdwp m/rir3 fw0(k9-nm light?    cm

  When blue light of wavelength 440 nm falls on a sinywdxj5.;+ hqlnsfx5( gle slit, the first dark bands on either side of center are separated by lnfs dh(xw5.q5+ yxj; 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls o (d 170.;ox *kj2*0alzyj ttwtllufofn a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m aw0j*a2w1;0 xo ytku7dl*f(tf lolj.zt ay. How wide is the slit?    mm

  If a slit diffracts 650-nm light so thdu lf8:2+cu f+9jp9t ay 7ipiq4idt-dat the diffraction maximum is 4.0 cm wide on a screen 14-+t t9q+ fcdydf8 i7i:i9adlu jupp2 .50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelenghjf0ku-+:o ey 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 maximi);1 p)dgsbxrpfa 4i) )cgr nt1r jf.-um when falling on a grating whose slits ar1;cjpd itr.rai-fn)1g bgrxfs 4) ) )pe $1.45 \times10^{-3 }\;cm$ 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 doe6a o1g.co rkgdl -pv18s a grating have if the third-order occurs at anp1d voc-6ga.l18ok gr 18.0$^{\circ}\,$ 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+07zdz 2q2xbvfvsda . a diffraction grating is observed at a 0 b27xa2z+dfq .zdvvs15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingxuzf v8w)y)pg(kvrub1d h0 (9 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 ;nv x olmk25 3f0dmp*orvn.1pbq0wm)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 ;:jw:xke wp.xorder that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm lasewe. xjw ::xpk;r light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on eithef hitj(,gu-5y7psx5-ja ts,z r side of the central maximum when white light is sent throu j ay,xjsz5gfthiup--st, 57(gh a 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 g taog-sxj hzn9 u,(0z5s67nvkrating with jnxvnz0 ts 59 -(6uzks,h7oag$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic lightz3 ic ,.2gef,fbo sxf/ 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 h mm. syngcs/h 0*8k:pgpt, twx1z/ bu)ei:f-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 thi;e pc*s3cs7cq d-2qi sck, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by whitc-p2i;dsc 37q ces q*se light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if jjl1i)vh pfnca),4f)the glass plates are each 26.5 cm long? c,4jja )) nfph1lfi v)   cm

  What is the smallest thickness of a soa yqp 616ubwb:)fzb (ztp 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 6lvu j. gh d/q+dnt6+oyellow ($\lambda\;=\;570\;mm$ 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 (n mp0imth2 87:aiw tsu1ot counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface 1tum0 2w p8ha7ms:tii(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, as i v0s eahgsr.im.o8xl20,y kr/n Fig. 24–33. When light of wavelength 670 nm is incident normally k02a8mr0x ehsr yisgv./l,.o, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be9 vzszcx8i3 gs (zgu6y1 )us-w between two flat glass surfaces if the glass is to appea(s)69x-cgg wv z1 z8yuis3szur 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 diamondz deb-i)7bd9bdhht hz2 )qy97 $(n=2.42)$ 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 o x4ueh+ud7( h$(n=1.36)$ 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 appy4: vkoyso7w(aratus (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.4wk (o7yov:sy92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the ligo7;0iou; qwcjht entering an interferometer if 644 bright fringes are counted 0u;;oj o7 cwiqwhen the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. Whe)gf me pv+vxl(b3g t n-,oq3s1n the micrometer is tightened down on a thin metal foil, the net number of bright fringes thatt (olb+x,13pqs gvgfmv ne -3) 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 mirro)dr6oe.: ,kol mqkk-gc,:a thr $M_1$ 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 interferoxlqw:ht)v* x(meter (Fig. 24–59) passes through a small glass container clhv ()xx:twq *ontaining 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 that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oug/s4zs.xmjp yw- 72 ke3a1buriented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle fft-mxh(cb/+ cor an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the liy5 xe *4loyci9ght is hitting ti9o4 cyxe* 5ylhe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through gklxw3 rv-:r90wf fc0 them is a maximum. At what angle should one of them be placed so that the intensity is subsequently reduced by h w:xvklwc093ffrr g0-alf?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as wjvmq)tlv;yi/ n( 2*aau 1rd5to reduce the intensity of the in;tl/i5 urv*ad w( y2najm)v 1qcident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are ori9htupy((e8jwl);9t v bhn72nf jgiy:ented 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.+:/sol ,j9 keva6jic5dmwciyz ;f u -: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 re8fpo 1 zt32hxyf0) xofflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface. t3 zpfohx82xo)y0ff1
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 sheetsxyb,w3alp f5i5.()p(5h eso id 5uxrt, each of whose axis makes 5 b5a5l, xup)d(wriyox. (ifpseht 35a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength kny8*yoygz*+b ;pg y;,nv py3$ 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 reflect5 -,-hz m rdnxkp hogxy)pqhu0)k6j1 6z,h*uqing from mountains or airplanes can interfere with the direct sign- ng,x hhy-d5q06 )rx mh,6*jk1uu hq kop)pzzal 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 sourcesuvt+-4r oxz v+ passes through a diffraction grating with +xvtr vzu4o+ -$ 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 s:objc h6wkc1 0lits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength prod1obj0 chk6cw :uces 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 ide0facn ,a.-emo ntical antennae at the same elevation but separated by an 8.0-m horizontal disan, co a.f0em-tance 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 ann91w)t.cj0 .,inr+ sd4x*ojjudvqcw outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignori*o0)sj dj9dc,.w. xcnrnwi 1 vjt+q4u ng 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 fallgn2h.5 fc9gpyh8 v c(ns on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certa i8qbq7b7vkzn::8rxq k e;i4 lin beetle have a series of parallel lines across them. When normally incident 460-nm light is reflected from the wiebb 478:x;k7irzq:liq q v8n kng, the wing appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is to ber-0 .2)jgno)huvvj0 2hfejb gz yj az3rx(j13 no second-order spectrum for any visible0jg3ej 1v)hxn jbhzfz203(gvyoarrj ).- u2j wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white lighh*z ry; u qud)5ao6)28 o2wlce:xojazt produced by a diffraction grating alwaysaa5lx*jo z oy: 2uo);ceu2 dwh6)8z qr overlap. What wavelengths overlap exactly?

  When yellow sodium l 9slnj z 6 j)r/mjqpt:(n(9txpight, $\lambda\;=\;$ 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 diffractn qie9hic gd9)v .8nw-ion grating with and the pattern is viewed on a screen 2.5 m from the grating. The inc ie)v-d 9c w8.hq9gninident 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 materia: eosz zh.(uj/l if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce rez(/z.jhu so: eflection 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 a f9qr, ie,o)aw: i go3othin sheet of plastic film in air. The reflected lqo or39 ,o:ifgiew,a )ight 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 thicknesfh5 laqg-uir5d;; n7es needed for 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) 2hwr7z7er: z9t nrhlr/j)sq1 thickness for the air layer between two flat glass surfaces if the glass irze hrw /r z 7qrnjsh7:29)t1ls 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 la(b+*fv vh0 vvbyered 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. Discuss the relative size of the minima compared to the maxima and (v0fb *vv+vbh to zero.
24-30
24-36

  At what angle above the horizon is the Sun when lightuyz y- 69s;h,s l.dgpf reflecting off a smooth lake ih du, 6.sz;y9y-lgpsfs polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroidslm0 b x(fqo(f/ww0emj e1d.v8 be placed so as to reduce the intensity of the incident unpolarized light by aef.be/0x(wj w1dl 0 fvqm(8 mon 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 polarizerl:au /5h;+ 9djwjnhgp.lvmd - sheets whose transmission axes are at ril: h9pn j ;ld-g+ h5w.mavjdu/ght angles. A third polarizer is placed between the 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 succession with their axes vea3i(p48oeutk v w0v-irtical, 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 cu;bqp2 hk :k+um and is pointed at the Moon, which is approximately 380,000 km from the Eap2ukq:kbhu ;+ rth. Assume 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 ayh x4.oac2n:c flw;0:py hmf 6 pyk6b5 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 e3xih tgo m.: s;0scu7$(n=1.34)$ 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 5n+s3qb;,ydg. xxh g j6.0-MHz radio waves in phase with each other. They areq xgx;ys,+bh jgd 5.3n 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 coy.5.+mdh8 : eihfpssk ntaining two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism (Fig. 24–5k5f :sh ..ey8p is+hdm8).
(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 s***o w)+js t9lzfh( 5qffma gsurface 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