Does Huygens’ principle apply to sound w;+fsn*qyv1z vmsvjd/; r; vo-aves? To water waves? Explain.

What is the evidence that light is ene +3 nfz9ab.zuargy?

Why is light sometimes described as rays andopn3t/mttj45 *ff0c;5 g3htsn yhk+ u sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; -x tzazc0vt,r q.f dcy(9a4a8yet both sound and lightaz- qdc 4far(z ,ty8ct.0 xa9v are waves. Explain the difference.

If Young’s double-sli8vkfb1x 9 b3.a +ppbzit experiment were submerged in water, how would the fringe pattern be b 8+ixbfb3v 1p.z9apk changed?

Monochromatic red light ats8qwfizdn)763dv , octi 2:is incident on a double slit, and the interference pattern is viewed on a screen some di wn2o7 t6:v 8tqfs3,zdcdai) istance away. 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 in0)x cw5rpgj p8terfere if their path lengths differ by how mc j 85p)rpwx0guch?

Why was the observation of the double-slit interference pattern more c ;vo lu;k3xtx*onvincing evidence for the wave theory of light than the observation of diffra t;lxo*3vuk;xction?

Compare a double-slit experiment for sound waves to that fo.2cvq ln1b-ocbtu s g e3y,(/g 1sprr-r light waves. Discuss the psr qb3,/ vgl-bru-gc 1( ce.tosn2y1 similarities and differences.

Why doesn’t the light from the two headlights of a distant car produce an innl3g:twk. 6fier dd;8terference patgklrfe:dw 8; i nt.d36tern?

Suppose white light falls on the two slits of Fig. 24–7, but one swtea miqvqtx5 b1lsyc21(-*0 lit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the sc1vl ib( * qq wmax20-yttc5se1reen.

When white light passesvnz s+) j63li5sjsi8zg ze;o- through a flat piece of window glass, it is not broken down into colors as it is by a ps)jsgvi ij-+ ;zls8zozen5 6 3rism. Explain.

For both converging and diverging lenses, discuss how the fomt daqp 7n65f- 2s6hitcal length for red light differs from that for violetph mq in6 -t26saftd75 light.

A ray of light is refracted through three different materials (Fig. 24–55)6 9y i1 6ke2zpwavxv0n. Rank the materials according to their index of refraction, least to greatesz6 1vx a0pnwyeiv6k2 9t.

Hold one hand close to your eye and focus on a distch)r9d snd6n0ant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.0dschr6 9ndn )) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole apparatu.oim*n eo-6 lu-iv 6dks is immersveuk6.iodm 6*i-ol -ned in (a) water, (b) a vacuum, instead of in air.

For diffraction by a sitalyev .:.kfgyjo92. d*;4 m6 nlkmvtngle slit, what is the effect of increasing (a) the slit width, and (b) thevl.v.m4 gtaol9.dk6* n2y;tj:eym k f wavelength?

What is the difference in the inters8yv*q re2q6 fference 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 t emdu3*dza3 uu0.o2 smhe advantage of (a) many slits, (b) closely spaced slits?a0meu um3dd o.2 uz*s3

White light strikes (a) a diffraction gratin*vpngp /qf5 h7, gipx2;spoj/ g, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontalpjh f;p/ ,7ig2pq*npvg/ x5 os 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 ag5t q,inh ed1lpkj-q +ho+m ci 8w(q*3nd 700 nm, incident normally on a diffraction grat, +qlqmc(-qw3he j1iogpk*h85+ nditing, 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 film like a soap bubb9d7u:tg;9v5l le xk gtle and not for a thick piece of glass, say?ug:t9vg;x95kdtl7 el

When a compact disk (CD) is held at an a;4b d v5m8qyio3xnd8kngle in white light, the reflected light is a full spectrumi3d qmbv;k5x ny88o4d (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig.pfvt87riu,gs s 5jk+ 3tb dp38 24–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. (kmzeuoh e4 ok72;-rj br**luWhat wavelengths do you suppose the coating is desig7;*(r uj hokrbeu*2-oz elk4mned to transmit completely?

A drop of oil on a pond appears brigh3,niub n+62imaorjn. 5rt .vx t at its edges, where its thickness is much less than the waveleng,nox.. vnnri tm6air+ub5j23 ths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the nature of lightymxams-;ii ll 2-diqzzg/( ,+?

Explain the advantage of polariuimfcf5a;(:zv- 7.i p(ck hbreny7 1v zed sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizib hvlc8j p91j,3lr7jaypd - -sng or not?

Two polarized sheets rotated at an fbldkk/ ;3lt )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 skyk78x y:m w0ixu if the Earth had no atmosphere?

If the Earth’s atmosphere were meu(*9za7h q/7c1h .f wk cpkb50 times denser than it is, would sunlight still be9kc*f(bu1qh /p hm 7kac.w7e z white, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm agh hrupsq a:tnr(3 b+qh6 +/h(part produces the fifth-order frinnth3hqrbh6+ uhpqa ( /(r:s+gge at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fring09tun rn, ynhu-0o:a9yzt :o sjhcr9 0*-iozse of 610 nm light is observed at an angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two versd,i mjfw/z -ji*+ rlj-g*5yk y narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the-fd-+yjjm jg*s /w5k *,ilriz center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nm, falls onvk pn p0y).yji/--pyu two very narrow slits 0.060 mm apart. How far apart are the fringes in the c pkj-vy)ynpip /-u0.y enter of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two sl9jr/v3n*ot e vits and produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separrt e/jvo n9*3vation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, g1s;e8 uzlt 1uhow far apart are the second-order fringes for these two wavelengths on a screee11utslg8u z; n 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light ofvg6bbqu0 n, 053uitee wavelength 460 nm gives a gb 5tn v60ub ,0u3iqeesecond-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart passx 4fv vm.e48+fykuv t+ through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle rey 4 xvefkm+8tu+. vfv4lative to 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 slit in Fi -x ma/2*ib ml7(uylevg. 24–7 so that the two w(el2/y vib lm-u7a*mx aves 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;g -;*y2 *drixijgb uc 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 ti*r; i d;jg-u*c2bxyg he same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits sep 5z(1 h d2osh:lziie 3nz4;gw6bws58ewjeoj 9arated by 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fringes on a scree i s 23wz:zzw81egsei5o(hbd 65 ;wjj4 hno9eln 5.0 m from the slits.    mm

  Light of wavelength ef08 td-h9 afy7d.c h8y1yjzx480 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 doublen*e-m kfgpus 4w. k+qf*cq o+)-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness ofqo4.*uqk mke-p)fc+g +sf* wn the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceey , cmj*t.ju.id that of violet light (400 nm) in silicate flint *.y,uj cij. tmglass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass atq0rjwt b88 3yhj.e c3h 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 wavelengb liq3cd9pz7w/l 0u8uo4s xj4ths, $\lambda_1\;=\;450\;nm$ 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 th)mhy9iqc-ut1 6ze i, qx :)qgee full angular width of the 1ige)-myq cxz tieh,q)9:qu6 central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls o +:(jobbmy+n gn a 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 iay aro9fbk9m e*u 1iqs;*4/ ovs $ 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 ilu+fda a +vm+x8luminated by 450-nm light. What is the width of the central maximumvx mf8ad+ a++u (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653e(z2d19z0rfpu c4 lkc nm falls on a slit. If the angle between the first bright fringes on either side of the central m 2c9d flp0c4 uzr1k(ezaximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m behind a 0.0348-mm-k2 2sz-p/gb acwide slit illuminated by 589-nm lig/kpg-a2c bz s2ht?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dark 4ng38)s 9tmtdnicxn0 bands on either side i 3)tgtnsmc094ndx n 8of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength5nn; 8(hojx u*cqotjn. bd 8z) 415 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How 8;bhd(nnjuo 8nj5.ox) q*t czwide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximux wiw*. *jw/zgp2 7rzwm is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for ligh 2zx z wjrwi/7*pw*gw.t of wavelength 420 nm?    cm

For a given wavelength zo1v- dmj/3 lprfp)m- $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light producp0dqz9n)a1st lt4g b/e a second-order maximum when falling on a grati)d tgnaq/ z41bl0pt9sng 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 occurs at+j hs3x -mnty8 an jtm-s + h83nyx18.0$^{\circ}\,$ 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 grl8k4yixrt:(s(ar:mcn h 2y7+mu l5uqating is observe+ ml cqy tk u: ur58y7s:xnai4r(l2(mhd at 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 3+qwg vvo0u71u+ samb $ 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 o tgbon y/w .n9s9syz8,n 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 specoe :+*6t p).ofoxxnkp tral order that can be seen if a grating with 6000 lines per cm is illuminated wioofno+xx* t)6k:p pe. th 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of the cer7rz *b)a+ik,ioar /, gcb ;wrntral maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm fbai, rr*rkc)rz7/;o a w+i, gbor the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a gratia5u w*fo -zji;kmt u)i-)b 8eong with uj- k m -ow;)fiizu*e5)oba8t $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromat8 0lla y:cwszijh++ 9lic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum lines are3ahlc4rw 6+s*o k , tcl0qh9 .sfm+wxb 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 120q6th. 7 lxt74 -fh vqqkh;4wyt nm thick, what wavelength is most strongly reflected at the center of the4h 7h-tq4x; ywqv.7lfhkt q6t outer surface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glas pcu87lvm /x;js plates are each 26.5 cm longvc/8 7mujx lp;?    cm

  What is the smallest thickness of a soap film vr.9nz b:kff.ek(vqo(cet-4 $(n\;=\;1.42)$ 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 (k k 0ehs 27t)ahs0gtr3$\lambda\;=\;570\;mm$ 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 countinslp6k+,mocr ) g the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is the center c)molkp s,6+rthan the edges?    $\mu m$

  A fine metal foil separa syyu df rju.5jgwov)65+ .q2jtes one end of two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each ej y su g5o qw)ju5.2yf6+.rjdvnd). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass surfacez,i o5) ui/x+,ud woe9ls-xlvs if the glass is to appear bright when 450-nm light is incident normzlol/ u5 i,esw+)x, vo i-dux9ally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspectm .*vaoyd qb(0 3z6ytded 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 alcoh 38s8a: nciytool $(n=1.36)$ 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 im iin fu/ohxd/56) pl-;fov2 f sahqa.3,dse;mmersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48v dx onf6a -s;p/.hhmf)5a isl;q3fe u /id2o, cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if 64xas;- e) zqbf7 ;;sz8cnws2y y4 bright frin b-;yx; na2zs8sc;fq)e 7zwys ges are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mi pz .qvl-/-lzhp1s ry5rror of an interferometer. When the micrometer is tightened dow/p-qs-.vlpz r1 hzy l5n on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirroret z h+:hy4krn3mi/f3 $M_1$ 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 inter1 f luz;: rll7y,eun /+l e5)pxcqrp/iferometer (Fig. 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 thfl+7pr1:pu/i )rze/ec u5 n l;lxyq l,at the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at -bjbeb 4f t n.ncro.-42olm3j65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle fowqcb66jqhc) ggysd874/ mfq8 r an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if tkl uwel80fm uhkf8418he light is hitting the dia80l81 k8f fu4hkmeuwlmond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a m6m 8m kwg-iatb :v(j5 t9otsk-m7lpw, aximum. At what angle should one of them be placed so that the intensity is subsequentst7wgpt6 a5m-j ,98bkko (: mviwlm-tly reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Pogk c u.r b8d*sbfc59.olaroids be placed so as to reduce the intensity of the incident unpolarized l. gcbo 8.5sfu*kr9bdcight to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at az;l, -z,w8nds ( msys40$^{\circ}\,$ 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 orientu.e,g2qq0 ic2niy /q ned 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 angn12h -omklh:wx t3k w9+c,h zole be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to B+ n: wh9l 1mto,ohk wx23hczk-rewster’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 s+p4gx sah 6to*uccessive Polaroid sheets, each of whose axis makes a 456gha+ 4xo pt*s$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength iy fuug 7*4msq4m, *sehdvm6.$ 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 mountains or airplanes can ipy3 vx.3 t06ny etxo,nnterfere with the direct signal from 0ttp3n .y6vey,3xnoxthe 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 sourz5mmo;s30 3k*,d zjxks2 xjzrces passes through a diffraction grating with 3z2mkd kj xo3zz*,mxrs0;s5 j$ 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 slits 0.60 mm apart. The sbi *m(5spbk:2h ad s8vcreen is 1.70 m away. A second sou k hbpvis:s52db8(a*mrce 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 9,l9q1ydh z2v 1 cuwfdtwo identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. w19dl uhy,q 2zdfc91v 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 bac / ld+qp2 7ss u(eut3l4xxsov5k from an outside 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 whistux(q5p tso e4su l d23/l7xs+vle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit 2 gdi*arb-ki 7of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of1sd:.ipmtp ntl; 8 q2g parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an tldmn2 pgt.s p:1i ;8qangle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is to be no secoj); 3ykir5so mnd-order sp5ko3; ysm ji)rectrum for any visible wavelength?   $ lines/cm$

Show that the second- and tr5. 5xozko,oej 7. mdzhird-order spectra of white light produced by a diffraction grating always overlap. Whzzm. r 7o.ko5dxjo e,5at wavelengths overlap exactly?

  When yellow sodium light:u c-scub/z -w, $\lambda\;=\;$ 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 diffr p6je0s2; cx 030ayita9wouqs action grating with and the pattern is viewed on a scr2s y3i;09 quoj0s0aac6 x twepeen 2.5 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 mater aspw0r4bbpf2x;x: 1sial if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 6 x1pws0 pa2b: 4sr;xbf00 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelengthe,lv x0 lvgy9n10-zt l is incident normally on a thin sheet of plastic film tz09e,l -lyl0nxgv 1v 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 tvm8)amt8 qhwh3 t49u1i0gki h hickness 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) thickness for the air layer betweenh9g.w2q/ zt rek-ag,x wl:c*g two flat glass sugklwz. c2e,x:g-r*q9th wg/ arfaces if the glass is to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted throughm3,bk 4owujm/ l9xv5v 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. Cw jv ovm3,5klx9 m/bu4onsider 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: 8apce;ctea . is the Sun when light reflecting off a smooth lake is polarize e8;e pc:.tcaad most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placestlx+p*q+lq 9ji k /4od so as to reduce the intensity of the i l/*qt iqk sx+9op+4jlncident unpolarized light by an 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 whoserr(c2: zivpo 0m+3olnvq1f7r transmission axes are at right angles. A third polarizer is placed between 2 izr pfo301n(r:+ qolmc7rvv 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 +y.4-zuxwy wa 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 p2daowgb.ui h k6b3,u p25k9pslit 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). Estimate 6hubap59p ,3.b iwk p2uodk2gthe width of the beam when it reaches the Moon.    km

  A series of polarizers are each placed ati6; mk/8ca bvm*mtd +d 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 mp/3 :o udrjr5zy5 js. hqc3: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 antennas radiating 6.0-MHz rad :1.- eqqzy 5xetjty1mio waves in phase with each other. They are located at point. qxtz-15yme:qt1y je s $S_1$ 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 nm and 6ybwxb */aq9s 650 nm, enters a silicate flint glass equilateral prism (Fi x/aqby9 w6bs*g. 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 surface and one wit o192fm,lp8m) :i+mg hecjjpc h $R\;=\;18.4\,cm$ 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