Does Huygens’ principle apply to sound waves? To water waves? Explain.i8w48szf qs.; 9 zgpjxs ,v(zd

What is the evidence that light is e1igvh u +or-qlg24 iaa5, pux-nergy?

Why is light sometimes described as rays and sometimes as waves6yv gvf2tfr+* 6:fuhi?

We can hear sounds around corners, but we cannot see around corners; yet bothymf m);nd.oa.sr8x )lf rp0)j sou;80jl). xy.pf)f sd)omrmarnnd and light are waves. Explain the difference.

If Young’s double-slit experimen*;w7 )(iipi e evry5mzt were submerged in water, how would the fringe pattern be ch7*)irepi;vw 5 i(yzemanged?

Monochromatic red light is incident r ;jkhz0kh5 -vd obb7v; -svjv +bqx.8on a double slit, and the interference 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 light source.v;bkjv 7v0dho+s bjzk.8 qb5x -rv;-h

Two rays of light from the same source zfslb*q ye :(5destructively interfere if their path lengths differ by how 5f*qby(z es:lmuch?

Why was the observation of t h3*4d o;r* 7lxu ewzc*ewjze.;bq 4nhhe double-slit interference pattern more convincing evidencend;x7*4je4cbeq ho w3z *wrz*eu;lh . for the wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to th q9axzj4 6;3km7weozt at for light waves. Discuss the swqe4kz m ;6jt37o xz9aimilarities and differences.

Why doesn’t the light from the two headli8a /mogg9zfm pea) +.aghts of a distant car produce an interfep o+me zag/)8aa gfm.9rence pattern?

Suppose white light falls on the two slits of Fiykd x24gzt.* j1agb8tq;1r eyg. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screenxjb .d;et 1gr4y2yqkz 1 *8tga.

When white light passes through a flat piece of wind 7kfg 9n 74dab..ufbzwv2-6de jp ek-5isil.p ow glass, it is not broken dd-eg9d blsa-7fjk .enfwzp.4v2ui kibp56 7.own into colors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length s + st:7szl(3phseuvygb)5x3for red light differs from that for viss3 uv 5l7(gbsep s :hyxz3+)tolet light.

A ray of light is refracted through three different materials (Fig. 24–myzrj4 ,9rj(m 55). Rank the materials according to their iz9 jm4mj, ry(rndex of refraction, least to greatest.

Hold one hand close h9i;oowh, vabbfhlo8 dl33-7to your eye and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain twdb ailh-,l9ov7ob3 o ;fhh38 he best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whoq90 lc warp*-wle apparatus is immersed in (a) water, (b) a vacuum, c0 rwpaq9-w*l instead of in air.

For diffraction by a single slit, whao2k*bpolj8r4 khtwt3 om 9i95t is the effect of increasing (a) the slit width, and (b) the wavelength?ko9l tp 9ormwh*o j245i8kt3b

What is the difference in the interference patterns formed (a) by two slnwd0vz3+enml0 nl mmv*udu2uz 7l 0)3 its $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of - *3aykvh ,oaa(a) many slits, (b) closely spaced slaah 3v*yka ,-oits?

White light strikes (a) a diffraction grating, and (b) a prism.u) , bvcl)tknhm8yjss02 35hc A rainbow appears on a wall just below the direction ofcb 8l2c0m ts 5)huhjk),yn3sv 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 nmd4/u 276btsj5xtug tf and 700 nm, incident normally uu/6tj t bds52gtxf7 4on a diffraction grating, 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 noticeable only for a thin fil j2ql* wyj :/rnc )7:ah ;jxk):vfdyvzm like a soap bubble and not for a thick piece of glass,*v2d:;)k ra wzlv : jfncyj7x):y/qhj say?

When a compact disk (CD) is held d l2nq: fz.mmh;bre05 at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you 2 dz5b0fhql;m.nme:r expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther fz-yj;zkbo9vx ):p 8 h f2lgoo5rom the center?

Some coated lenses appea3u,aymw q7 kelx59pj0hc 8/b kr greenish yellow when seen by reflected light. What wavelengths do you suppose the coating ia,kb xq 3jyhe k/ lc57u9m0w8ps designed to transmit completely?

A drop of oil on a pond appearoxf)x.p2: r -fpd 9jcjs bright at its edges, where its thickness is much less than the wavelengths of visible light. What can yo:p.x f 2j9jd)oprcf -xu say about the index of refraction of the oil?

What does polarization tell us about the nature of light?qr7xoy/* l4bszv,h -r

Explain the advantage of polarized sunglasses over noo7p;+2 ( s ;( jmrqbwkt6f l8yufct0azrmal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizing or not?j3o ek31 .ej*+h32sml hwmfld

Two polarized sheets rothe x:4u .v kef6 mjbo1)zmw1q+ated 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 if the Ei8sr 1wi8gha-arth had no atmosphere?

If the Earth’s atmosphere were 50 times denfu900bq h;(zsv7mo 7ca1o e xqser than it is, would sunlight still be white, or would it beqxs;mc e1zo v907f07o(b uaqh some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fift-kmi7gag f i53.hwdp,h-order fringe at,3 amfph -kw5digg7.i an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at an anguzn :bss/oa v/9)aqm 4le of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls z6/* a tldcr; inji .gy:m3vz,on two very narrow slits 0.048 mm apart. Successive fringes ;, 6.iygcn/ v rajmdt3zi*zl:on a screen 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 fj0y, /l aica8 a1flp1prom a He-Ne laser, with a wavelength 656 nm, falls on two very n,1ciala/y 8pjfl 0a 1parrow slits 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 falls on two slits and produces an interferen7j1w dagvm6 7mce pattern in which the fourth-order fringe is 38 mm from the central fringe o67w7m a vg1jmdn a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passe*qg c n;e-ypx 8*c4kbls through two slits 0.58 mm apart, how far apart are the second-order fringyqkcxe *-8bp; c 4*lgnes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, bh(.*h01i a1+4rux/ yi q p0 gkkkrqapit is found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at the same location?ra kp0 q.au4ihgky+1r ip0(*1 hqx/bk    nm

Water waves having parallel crests 2.5 cm ar 9 wxja/ja*0 36+sd0xvn yf66ic wwagpart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “j03w/6 ay9 rwv6 0njcxfwa+xa i6dsg*straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower /*0 n(jg wti u/s0abi1 pxa0nuslit in Fig. 24–7 so that the two waves enter the slits/xt nbws01u ( jpuai n/ai00*g 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 maxima h,y;sbonlk7:*z fenu- v) / t+7edhf6cxjm7um for light of wavelength 500 nm is located 12 mm from the cenj/:-dv) l tha*x+ue 677;nz7s nfhyeomfb,k ctral 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 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. Find t.4vn 6atdz2ir he distance between adjacent bright fringes on an24za6r i vd.t screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on t uef, bzyilq9:t (m+teek://d-dk2 ngwo 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 offyf8,h:8 v0ktm 3x;wmw0k gov a double-slit apparatus illuminated by 640-nm lightxg3mmf;8ow ,fwv y8hkv0:tk 0. 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 red q-tlv2y1 5n g jp,zl1dog (z;xlight (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fixgz1-gzd,n;( lp 52lv t1joq yg. 24–14.)    %

  A light beam strikes a piece of glas k;v r-0ue3,1-lmvls gh dc+xjs at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light containing two wavelengths,s odlck*;v* o0d g1,yuryma-x4mkz8 0 $\lambda_1\;=\;450\;nm$ 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 angular widto.rd/ xz(zqt ,h of the central diffrat,(rxzd ./q ozction peak?    $^{\circ}\,$

  Monochromatic light falls on a t(1ctv/l: euf -4myfl 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 slit that is 51q+g xu yr 4ly0gp2uh$ 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. What is the t( z1:fkrx- ihwidth of the central maximum (in cm) i-i1 k(:thfrz xn the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the39vlr .g/(i i1kescsc angle between the first s i13 le9rk./cscvi(gbright 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 0.034gn,p cj2 qw0;dqfhn(38-mm-w 2g nfd3hnpq;w (cq0,jide slit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on ah en (vs 41x qh03;py)2fyford single slit, the first dark bands on either side of center are separated by 55. ;r h2 fdnyov f3x1h(p04)qyse0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single slit, it ce9vnnu-lk9fc 9 yrk.e, g2yarm6s) z 1reates a central diffraction peak that is 9.20 cm wide on a scree9 2f9l6 eezgr-s my,vnu.n 1)cakykr 9n that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum is 4.0 cm widfi e(qy/i x.sa:h28gq e on a sieqq (i x2h: s/f.ga8ycreen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt78 o3ha)cib 1hj9wacv tl8uo xmux6-+h $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm lig ctwm i65.m,wwht produce a second-order maximum when falling on a grating whose slits ar.mm6,w t ciww5e $1.45 \times10^{-3 }\;cm$ 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 theqy4c i f/,e8ac third-order occurs at an 18.0qf a48 e,/cicy$^{\circ}\,$ 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 gwf pf9s z9as3)b a/e)frating is observed a e/wf)abfsz) s9p39fat 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 zrz k 34svh4trd541j m$ 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 normal5sa-a s (i;wrq1 kahm8ly 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 ordek/v0/gyf0 xoplet( pe8ia(j 3 r that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume norp3(ly(8eiegvp ft x0/k0 o/ja mal incidence.   

  Two (and only two) full spectral orders cwroetrq.-t8jv-w q r,t3q7olp;v ) 1kan be seen on either side of the central maximum when white light is sent through a diffraction pl7) e rq, r-k.oo3;jtww v-qt 18tqvrgrating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 75q3mh hvto p 2f-/u4upl8ei8v+)5lwch0 nm falls on a grating withu8 pmwvi2vh 3h4-o e+) qhcll/5p8uft $8500\;lines/cm$ 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 known wavelengta byn t7/;vg;3m 3kiwxh $\lambda\;=\;6.328\times10^{-7 }\;m$ 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 measure,pflv7 e5hp+uduey6 + d 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 thickns:1c0c b lo5xv7u8p w, what wavelength is most strongly reflected at the center of the outer surfacesn 50w lpuvbo8c c1:x7 when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fkmc+sw(1e 0 dvringes in Example 24–8 if the glass plates are each 26(dv0 ews +ck1m.5 cm long?    cm

  What is the smallest thickness of a 97/sn-l6oay 3u etlgb(acw / zsoap 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 (i5m5 qz +/bzmq- qegv,$\lambda\;=\;570\;mm$ 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):y)m*k.y7c3wvqnv.m7d k l gi1b whj ’s rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a pla3)*j)k1w.dvyw kmv7bq gh .yn7i lcm:noconvex 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 ef z03jy jw+yrb lol,14nd of two pieces of optically flat glass, as in Fig. 24–jbyy31j0r4z,+ lf l ow33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be bed , m5buj16qi2sp;z/yi zre1ltween two flat glass surfaces if the glass is to appe5,ijdup11zb2lsyi m q6/zr e ;ar 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 diamon egx6*vc g 5tq0s2bvb:d $(n=2.42)$ 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 alcohop 66l 5qpw:qcsnqal75l $(n=1.36)$ 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) i ,ah(*ls 37gh c0fyhlhs immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive llhhhys( 3, 7a gh*fc0index of the liquid?   

  What is the wavelength of the light entering a r/blahy)on* q,+n p/o4sh6jon interferometer if 644 bright fringes are counted when the movablr4+/jsooa6 l /p* b)ho,ny nqhe mirror moves 0.225 mm?    nm

  A micrometer is connectemd v6hlkr:- +rd to the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to tm+lkhv dr6r-:he 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 .ot35+qp e3zyybi1jd3 jln9or $M_1$ 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. 24–59) passes thr-d9 ,s,b wu:fs1yr fmiough 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:r,fduy 1 sb 9,iws-mf the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are obp:wyl 99xtj0 a.50zg0umxjoriented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle fpi c6qml4hal*8:/qvnor an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light isnl3x w iumim (qeh94.6 hitting t3l6qwie4mi 9( u.x mnhhe 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 mkyfz32-pqq*f zh1gbfr:r; y 8 aximum. At what angle shouly;qry 3fg8qkzf1h p:- *b2z frd one of them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed ; gn8oy4l; iduvmfc */so as to reduce the intensity of v odi*fu;clg/8n ym4;the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are or.yn 31 powc)omiented 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 xujt;job/ s7* at 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off the surface of wateg:c8lug us 6w1r for light coming from beneatg u8w6l:usgc 1h 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 su),a/5q ovx)uut j 9tv cl)wzj7omr/i1ccessive Polaroid sheets, each of whose axisca 9i5m) 7qt/wu,rvu j zoot/v lx)1j) makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength tzhc xu,fq-;2 $ 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 reh*effdexh7 .u .br g.-flecting from mountains or airplanes can interfere with .b d uf-greh.e7.hxf* the direct 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 sepa7lyb4n:l uw pb39zsu2rate sources passes through a diffraction grating with lwsz 2ynubl7: ubp349$ 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 /8 rhimzhnoxf,i2x+(590 nm passes through two 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 to the centrmh2,8 (f xniozx+/hiral maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating adm /1tq(mzq .n4fnvkp 4c,ix1t 102.1 MHz broadcasts from two identical antennae at the same elevation b4zx (f q.1in/cqmm,1tnvd 4pkut 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 from an outside doorway7kxf ::b5wk sp1k; o;ftkp(r e 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 on the playground ;: b sr(tpkkf5pkkewx1o;f :7 outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of width D at a 30 i ;ol,rwh)l+q$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lin mq+qjo-,y0i des across them. When normally incidemydi+-q,0o jqnt 460-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 centimeter must a grating have)ls3z)* f(dvj ae+nar if there is to be no second-order spjn * eazldf(3 )+sav)rectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectraje4d8w m4l(ypb ,pp p/jg-bh. ;lpa4 d of white light produced by a diffraction grating always overlap. What wavelengths overlap ex(p4al. g 8 p4jlpdp dm;wh ebpj,4-yb/actly?

  When yellow sodium light,4uzjluvga8z,* )n jy3 $\lambda\;=\;$ 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*ycdt.w 00x ezp 19q*xp)mk,(ingjvh and the pattern is viewed on a screen 2.5 m from the gratx jpixcz90nhw.g** m)1et q(ypvdk 0,ing. 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 cld+9so .9vsgjrg cmzk - tbf+ e;i717qvear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to neakcqst9s9v 7egmdzj+ ; g1i-vr+7ofb.rly 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 thin fa h6dp:-mn1gsheet of p-a:f 6dnmg h1plastic 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-ref,f,bfc sh . b g5oj9(o3pzzi-elective 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,ovn y+o*yj y+8 kmh .rwh1v2y for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nmokrv yh+h 82.myj*+n yov 1,yw light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layer4 c / iu-6vl4kbhvzs;0xxxe:yq 53exhed 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 maxim 5z3hcl/ k4 6 ve hy-x;evxiu04q:sxxba and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflecting off a smo(p u 6,zc hjqdmf.cm5: r,xu9soth lake is polarize9c,ju.p sd qrx,mzch6 :um5(f d most strongly?    $^{\circ}\,$

  At what angle should the 4tvpd 3/kk.c5 po; io;dn1e1ntlt0xf axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional facdvof;3 p ;oxti. n14tkk /tc e1d0p5lntor (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 wh* 0+3bcy2,arssqwcybe:dzd 4 ose transmission axes are at right angles. A third polarizer is placed between the fc4bzrdq s+bd,e y:*c 02wys 3airst 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 vertical fsjw/:kx d,1l, 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 s.7f 8-desg exkimuc f5x oj*./lit of width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estidmcf.s-ux* ej.i8xog f/57 ekmate the width of the beam when it reaches the Moon.    km

  A series of polarizers ar/ ,mf0tw/r pk r+a9a.j8lc +4dim bvmme each placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap so/ntk/92hf 4 jtsjecp0vl+x:b2 3y0e2lds k$(n=1.34)$ 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 antennaghgu0e9nh rloq4w8uo -qj 8 2 aswxvv.s0 8/:fs radiating 6.0-MHz radio waves in phase with each other. They are located ang0fj -hrwgvvl288oq :qwa/4x0u 89 .uhs o set 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 wavelengnrj8*4z .gq y3pduq o7ths, 420 nm and 650 nm, enters a silicate flint glass eqzp uj7 qrg4 *.y8ndoq3uilateral 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 surfaq ojuuy.l 9s 5, g4fa(rowi a:rt11c(ece 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