Does Huygens’ principle4 yoe2kou6qya) 7ewz0fv,g w3 apply to sound waves? To water waves? Explain.

What is the evidence that light is enc ydcxz .8+r w3p/0; 1naoewucergy?

Why is light sometimes described as rays t.c4,z bj8eve.ll4vrjq d em32/q7qrand sometimes as waves?

We can hear sounds around corners, but we cannot see arp y9;pjkhorn75; x /uround corners; yet both sound and light are wnr/h9rxykj;pp u; o75aves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how wo .y:vp0 ptl6xjashg:o .xt+f3uld the fringe pattern b pa.: x hfy6l3pjst:+x0tov .ge changed?

Monochromatic red light is incident on a double slit, and the interfe8ix/ : dkk,dc.fbq 5inkn +u(erence pattern is viewed on:.,i(n/ k e d8kkq5b fdc+xuni a screen some distance 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 7v0r(1rjpzvc f 5xb8 ksame source destructively interfere if their path lengtv587cr0f(z vp bxrj 1khs differ by how much?

Why was the observation of the double-slit interference pattern more cosu sc2whbk5e bhl/y3(j9qqy rb4 (5-jnvincing evidence for the wave theory of light than the obu2 45yqbke5j (ljq9rhbh( ws3/cy-s bservation of diffraction?

Compare a double-slit experiment for sound waves to that for lighgc3l) 4ey eo4ldy .5)zx.ke yqt waves. Discuss the si5xd kec 3qg .e4)l)lezy4oyy .milarities and differences.

Why doesn’t the light from the two headlig1 a0( eit fyd0qp-v5jshts of a distant car produce an interference pas -yt5jp0v d01q(iaefttern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is coveredl4rh+ 6d ou(h8wp b- 81:w ddhhiedwa5 by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pabwied5whddhd886ra4o p:l( h1u+w-h ttern on the screen.

When white light passes through a flat piece of window4gor-dm ,:2com pfdy,m1 cno1 glass, it is not broken down into colordcor-mmpg1:4yc on 1df 2mo,,s as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal lengt 0y(2dlku.o .iy-se wnh for red light differs from that for violet lyo(y k2dl-iu w0en..sight.

A ray of light is refracted through three different materials (Fig. 24–55)qiim3gp ;3 6nhw+vm (f. Rank the3pfv nm(+ iqi;mh3gw 6 materials according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light h; xov/69tgax3*1/aaa bjfp yflm*f5source through a narrow slit between two fingers. (Adjust your fingers to obtaga6/1 9lmh*;y3af* p tfjvo axbaf 5x/in the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit ic9oclo8g/*s n f the whole apparatus is 8s9 clc*ogn/oimmersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the4jhl+ p;y-y cr effect of increasing (a) the slit width, and (b) the wavelen;j+ h crl4p-yygth?

What is the difference in the interfe 5hiz2 c:zk apn:yh)3urence 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 sf+ik*m6u gu yqtw-j.zy,8tv 2lits, (b) closely space wyy+kvu 8,2fjgu t-t*m6.q zid slits?

White light strikes (a) a di,1jup awf*jw iv ,,,cgffraction grating, and (b) a prism. A rainbow appears on a wall just b,wwugi pfcv,j,a1 , j*elow the direction of 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 400ol5)thon1s2s.q m zv9 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observehos9otm2qn1s5 l .vz )d spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeablb2kc)i/: xq lun.r6xep ((irle only for a thin film like a soap bubble and not for a thick piece k(ib/qn6 2x) pr(url c.i:xleof glass, say?

When a compact disk (CD) is held at an angle in white light, th-swg,5c ,ic*wn.o avse reflected light is a full spectrum (Fig.sv cwan*, o,5ig.w cs- 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer toget/zoigl5p/f21du8s z kher farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What i-g,oi;gq 0 liwavelengths do you suppose the coating is designed to transmi i-liogq ,g0;it completely?

A drop of oil on a pond appears bright aw)ds* 3axa*gbt its edges, where its thickness is much less than the wavelengths of visible light. What can you say aboudg* *b)3 waasxt the index of refraction of the oil?

What does polarization tell us about thr6,o b (1p-giod6px3u kq4aa be nature of light?

Explain the advantage of polarized sepb nxt k/3nm3v7hab*x 5x7rt8+)cdlunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polqw:n r;3r*ve xarizing or not?

Two polarized sheets rotated amm a fm 7or)wud d5ce/fhw0/p p1:oo23t 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 i/ oey4 gcx+2aqnw-(ja5yz( tt f the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is, would sunlight st-d*iz zwr 2+tkill be white, or would it be somtz rk zi2-+*dwe other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-order6 zh/d2 g6b6yu aas1w(sle10jgsx )iu fring 0gse (12w /juasa66u)6izd xg1sblhye at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order frin i 5c7f+i)lz* 4ap.el- w/y9(op makazfqh i;rge 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 very narrow slits 0.048 mm apart. Successive fsah0vq /gpxg a7nxc 1c o5(19vringes on a screen 5.00 m away are 6.5 cm apart near the center 7hqvs1 g0 vc9nc(a5/1a xoxgp 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 waved4cr br kq0.ni/g;in3 length 656 nm, falls on twnrrg0dc ii/4b3q.n k;o very narrow 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 int8fug3ni .sk 3verference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is i.vgk3fsn 83uthe separation of the two slits?    mm

  If 720-nm and 660-nm li xt(y.(x.oh*fmps)geyf:;l w ght passes through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelen.xh)yy:wse(* .opmtl ;(gf fxgths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is fo;t42 34dyxmrz e8xzwzund 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 locatiow 3x24z ;zt8zr4y emxdn?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings 5.0 fbe zl6+d*d( lcm apart in a board. At a point 2.0+eb dzlldf6 *( m beyond the 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 front of the lower slit in Fig. p6cv90c rutz*u4 .wun24–7 so that the two waves ent9vp uz4cnu*wc ur.06ter 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 maximum for light of wavelength 50e7s mrqx/w m 1wcpi fo,/hw2/r2,ygmk+4bm/w0 nm is located 12 mw1ep m/sq74fxm ,b+ rmkhrwo2w2/cmyg iw //,m from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated bw1/ze2s w0r rfy 544 nm light. Find the distance between adjacent brighsrw1 fr/e 0zw2t fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm bpo2v rqve1k1y, cw+7 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) covers0i)rk.yk8c 5u1 g6 fe ov6lssu one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a k .fyl u)ceg 6su v0i8r65so1kmaximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approxb- x0ytxui(vh;)ow*iq s0v+ qimately, does the speed of red light (700 nm) exceed that of violet light (qxvh sxo) -i0*0ibv t ;(+qwuy400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piuy am8fpv nr:b+j97aa;i t8zz7p8 l *dece of glass 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 wavelendgzbi /bye9- o64;fip8wg e. kgths, $\lambda_1\;=\;450\;nm$ 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,1y *webm2,fgln.3wki what is the full angular width of thefbimkgw*1l ., ew3 n2y central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a svj,0o0 +g +clmya8k wxlit 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 ofa:a,yn) kel 9n a slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wibsv f(5-kbb ln ja4o);de is illuminated by 450-nm light. What is the width of theofbas4)(vl;b5-njk b central maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on i butb9-5te5k a slit. If the angle between the first bright95u5b ei- tktb 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 0.03s )kiu( w uap+)dc:r9x48-mm-wide slit illuminated by 589-nm lightpkuswc ) x+da u)ir9:(?    cm

  When blue light of wavelfxh 2q;36(3ltmcwnu length 440 nm falls on a single slit, the first dark bands on either side of center are sxc nm3hqt62fw ;llu(3eparated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falljl f2d-i-0j9*5mswr vyrub )js on a single slit, it creates a central diffractrjbmjl0u v *wry2-95)sj- fdiion peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum 86 p1bcm;a map.q/ltzis 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffpa m/ ;1m6 qtl8cz.abpraction maximum for light of wavelength 420 nm?    cm

For a given waveleng4qu:j1;tync:p0( iztw +qbj xth $\lambda$, 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 ,(x :yguojdvtl7vd .:maximum when falling on a grating wht7v,(v:d gloju.: xdyose 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 thipljk40tb*89g) at 9q8rfnmc3n:psi jrd-order occurs at an 18.049b9 mt0pl*g8a)p3fnijskq nt8c:rj$^{\circ}\,$ 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 bvd 7p3 kt+fkd9x //:efdjvwdagq8 05on a diffraction grating is observed akffex75v93ajq8d/ b0dgw+ td /:dkvpt a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratin g/v, o7bo5rpbg 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 normall. ;cs5u9 7x88vz unzp7ue enjuy 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 order that can be seen if u9qy74,)8 wqydvgv e0nj dc1 xa grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume ,7 v9j ec0yxd 8)qygudnw14qvnormal incidence.   

  Two (and only two) full spectral orders can be seen on either side of s-qf(kgmt x-5i9y3q k the central maximum when white light is sent thr3t qfygqk(s5k -mi9-xough a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing w j b51dwj 3or1js8+c3jzfr6ap1 knus1avelengths from 410 nm to 750 nm falls on a grating withru6cb1f1w8+a1 3rjnsdj 3 j z5s jkop1 $8500\;lines/cm$ 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 waveleng );505kp agek/n efx6 tln)uuwth $\lambda\;=\;6.328\times10^{-7 }\;m$ 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 lin c+l4 dwjpla1l:giu8 :n40hnjes are measured by a $9500-line/cm$ spectroscope at angles, on each side of center, of +26$^{\circ}\,$ 38$^\prime$,+41$^{\circ}\,$ 08$^\prime$ and -26$^{\circ}\,$48$^\prime$,-41$^{\circ}\,$ 19$^\prime$. What are the wavelengths?
$\lambda_{26.72^{\circ}}\;=\;$    nm
$\lambda_{41.23^{\circ}}\;=\;$    nm

  If a soap bubble is 120xfr v : 1 0vfyudxha-i()extww8pe-1 - nm thick, what wavelength is most strongly reflected at the fwv wx i:hev(x et8--du0 1r fpy1a)-xcenter of the 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 glass plates arec i8 aj fpvt5b;cuf48* each 26.5 cmta*;j cubf8f5 8pc4 iv long?    cm

  What is the smallest thickness of a soap filpm vx2)):)ssq yv6jf s7 h)xvrm $(n\;=\;1.42)$ 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 yel*xrawm5+e m xd)ad/6p6xxfr 4low ($\lambda\;=\;570\;mm$ 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 rin;o4fi o ;ssx0h . amvjom)g-l+gs (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens rm ;4.- v;oa sooi0g+h)fmxjlsesting 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 opticallyukp6j qp oi1 pj4zs66/ flat glass, as in Fig. 24–31 6 jsz66iqopp/j4pu k3. 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 xga(d:8j-o0 :wz 7ak wvn iu:3oiee) tair layer be between two flat glass surfaces if the gli:08 :dewnv g-(3) 7i:oztxjk uowaea ass 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, suspz q g:6n0ads*q2f os.qected 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 ma9o6dkq3m6vol $(n=1.36)$ lies on a flat glass plate $(n=1.51)$. When monochromatic light, whose wavelength can be changed, is incident normally, the reflected light is a minimum for $\lambda\;=\;512\;nm$ and a maximum for $\lambda\;=\;640\;nm$ What is the minimum thickness of the film?    nm

  When a Newton’s ring apparatus (Fig. 24–31) is immersed in a liquid, the diametes.j.5:j rj 6zaboolomc89a0 lr of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liqb6jm.l sl oja05jo8 or9z:c .auid?   

  What is the wavelength of the light entering an interferometer if 644 brb ke82kc:sqyv8q fj; zg *-foi4myd72 ight fringes are counted when the*cs24b28 zqfif: -mgyyed7vqk8k ; o j movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. When th ,) er4;jbwv ra)*wsqne micrometer is tightened down on a thin metal foil, the net number of bright fr*ew)v)nq4j;,rwrba s inges 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 mirror lcx45epy)kx .:nii2awd *hd;mfv q18 $M_1$ 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 through a small glb 5u;l,m wlzri :p,c-eass 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-rz l5; b:w,uc ,elmpi the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are ori8z 6. xr*:hlg-n mhw9zdzf 4gpented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s avfo l2 j0t (j,zoy.gf3ngle for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light7k2-8st8/ia w rfq*:rrkmkr w is hitting the diamo8/ krw2wq 8rrit m7k- s*:rakfnd $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that t h (08 dl+v*elem/ioxuhe light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequently reduced u vl +m(o0xi/8eledh*by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids teei c8t;34d06/r)ve hqfkp2:d pljm be placed so as to reduce the intensitk:te4) 0p/ d6eqc8l mhivd ;2f3prejty of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at 40 gb/w:b; yr9wo$^{\circ}\,$ 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 3 :9y+f 8-ylmenm rr+gk,np vb2 t+s;gn8.0$^{\circ}\,$ 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 anglek*,l lv ln.*oj be for reflections off the surface of water for light coming fl ,.l*v*oj klnrom beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface.
If the light is coming from water to air, $\theta_{p}$    $^{\circ}\,$For the refraction at the critical angle from water to air $\theta_c$   $^{\circ}$ If the light is coming from air to water $\theta_p'$   $^{\circ}$

  Unpolarized light passes ef i7wo+w64(qok.ht p through five successive Polaroid sheets, each of whose axis mo+i4.pwhk6 ( e7fotwqakes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength f/+*6 )dg p e / y566gasduirvxq hjgwmu,s)7d$ 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 interfem :tip ky6ly5n-/*pfn re with the direct sigiklymnn: /ty fpp65-*nal 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 sources passes through ang yu20wj+:y:7smlzq diffraction grating with un+yzmsy:0w7lq: jg 2$ 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 55 *8hty3vt koi90 nm passes through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknovk 38y5itho t*wn 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(y zkz.14rmeq 102.1 MHz broadcasts from two identical antennae at the same elevation but 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 miz4mz 1y(r.eqkdpoint 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 b.zxnen5 hk .d0go.g(h ack from an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what anglegkn.5nh d(og z. eh0.x(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 falls on a single slit of wpw-( ptrahcn;*n1 hd( idth D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a se aifa2nrr.z 1l1aa 2ce c;7b0xries of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an ana;fi2 r7.lba01 neaa zx1rcc 2gle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grad*(:f m67kztqtt 4wdtting have if there is to be no second-order spectrum fod tdft7kt*q:tw46mz (r any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light pro o9dt k;q iu3v ye-n1fia+d29aduced by a diffraction grating always overlap. What wavelengths ove2 ae+tvdni1 a3qo-uk d ify9;9rlap exactly?

  When yellow sodium ligm (xwk-i -ny-x,nxv+fht, $\lambda\;=\;$ falls on a diffraction grating, its first-order peak on a screen 60.0 cm away falls 3.32 cm from the central peak. Another source produces a line 3.71 cm from the central peak. What is the wavelength of the new source? How many $lines/cm$ are on the grating?
   nm
  $ lines/cm$

  Light is incident on a diffraction grating with and the pattern is viewed on5)a9yt6c/xo.ze 3 ev-iisme i a screen 2.5 m from the grating. The incit a 3x)eyi ee5s69iimc /vz-.odent 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 mat81h)bkp no9akjm19y werial if a minimum of 150 nm thickness of it, when laid on h9ybkp9 aw1k 1nm j8)oglass, is needed to 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 norma5( d/a.hbs*e1 fenrmn lly on a thin sheet of plastic film in air. The reflected light is(nfh.b 1dr*e/ ns 5mae 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 thicknes1 fmzg8 sx)9 yc.6yqtdjp h0(ws 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 between two 2 uy:a,)g(q ifbff5qgflat glass surfaces if the glass is to appear dark when 640-nm light is incident fq:,i q(5u)gfayb2fg normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light trm ndj49 4ujxe:ansmitted through 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 d4 njx4m9 :uejfor maxima and minima. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflectingbiw kxzf 6+n f:xfz/c/sdl eg9k* 99)i off a smooth lake is pola9+x: i99*k)bfcexf6/zdnis/zwk gl f rized most strongly?    $^{\circ}\,$

  At what angle should ytlosy(+ /c6 ethe axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) ot /6 (clysy+oef
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axes a(ppsecut*7tu;j 0x,s3,)/ s 4 ugbd yjrxv1x tre at righ exc73,rsuug;j,txb /(vxd4)jp 1py tstu*0st 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 succeso)kmozt n1*n2 f 0aj9fsion 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.v7h6/ qu7jxi5 sprtw90 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assum uih9/7t pr57vwqjs6 xe 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)4smyhym9 *lm 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 gfv 5 rb3pb;9 eb67tan$(n=1.34)$ 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 ra wtkyw3:7beop /,77h0hl vypgdio waves in phase with each other. They ahyev3k07thl, w/w p oby7pg: 7re 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 containing two wavelengths, 420 nm a3r+( ,ubslyxd 0tfqe 5;/qlhind 650 nm, enters a silicate flint glass equilateral prism (Fig. 24 lq dlubht5re,qyfi(;30/ x+s–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 wic 7cg(zlinb7 0th $R\;=\;18.4\,cm$ 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