Does Huygens’ principle apply to sound waves? To w,o k4q,lm-4 fkuqfhp3ater waves? Explain.

What is the evidence that light is energ1 w0t5o msfxe 2a.d *oqc,w-bdy?

Why is light sometimes described a,j 8+hf 9pjcgxjiq/1.bpj 1rhs rays and sometimes as waves?

We can hear sounds around corners, but we ca5ih ,*nlozm (wnnot see around corners; yet both sound ah*zo,lw mn i(5nd light are waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how would the fr/ ;vs4 *x0w6t8lw(v ebscmzgringe patternxs te lw;6 4 c8swvvgmr*0z(/b be changed?

Monochromatic red light +n2mg:6igs m pggk ui,(u*2ho is incident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how theigu*(o2ng miu2hpg+g m,k 6s : fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same sourcev8l0bk:v,bs9) +c0g2b an biisrt3zs destructively interfere if their path lengths differ by how muchivg3s :kcsb bz0i s0nl+28ab,) tb9 rv?

Why was the observation of the double-slit interfergc2 m yzma9 :q5.2qsjtence pattern more convincing evidence for the wave theory of light than the observa5 s.mma:z 2gcy2tqq j9tion of diffraction?

Compare a double-slit wzu0de 4/cu1 bexperiment for sound waves to that for light waves. Discuss the similarities0b4ewu zcu d/1 and differences.

Why doesn’t the light from the two headlights of a d i/dwqfrz7kuk otq).((p z.u2istant car produce an interferef(uok.rt)7 ( qk d/uzzw2 qip.nce pattern?

Suppose white light falls on the two slits of Fig. 2xfm+q. s m.9pl+: k, wqtb*elg4–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describmq pbql*w.lkemst9++g f,:.x e the pattern on the screen.

When white light passes through a flat piece of window glass, it rq+d z0ti-lg4 is not broken down i 4d itqg+0-lzrnto colors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how thetj9 )ru dts4 a0a(ik1qakzlq :y 2e,;r focal length for red light differs from that for viole(kyd1lr 4at,;ue ijqk0q:a 9tz )2arst light.

A ray of light is refracted through three different materials (Fig. 24–55). Ranbu4fe 8.gans8k the materials according to their index of refraction, 8nb g.4asf8u eleast to greatest.

Hold one hand close to your eye tuq12 lzn/ wd(and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that yolqn zw2( 1tud/u see.

What happens to the diffraction pattern of a singlonr2z3bk g5-zsmn 4s:e slit if the whole apparatus is immersezmzn-: n 24b3 og5srksd in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the e s,sd,ub/+u xgffect of increasing (a) the slit width,, b/ +,uusdxgs and (b) the wavelength?

What is the difference in the interference patterns formed (a) by two h.9nr v7jhr6+vu a 9.atw 1inuslits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (a) many slithb:h9o xxp(4 jk,oz-s s, (b) closely xk :j9hx-o4,ps( bozh spaced slits?

White light strikes (a) a diffraction grating, and (b) a prism. A rainq ( s0dr)y18czswrscrvp1 67qbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow in each cas80q7 yrs6c )crz s(qprd11w sve? Explain.

For light consisting-(mgqiv+.nix ti ,c0j of wavelengths between 400 nm and 700 nm, incident normally on a diffraction gr xj (tivqn0+. mci,i-gating, 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 bu ycwf-cp *,d;ciuii *)bble and not for a thick piecfii y c-c;,dip c*w)*ue of glass, say?

When a compact disk (qxtxv10edvbys:3j-),f z g-9 5d csll CD) is held at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if moxvdje 3f 0lq -szvg sb-1,)dtx 95cy:lnochromatic light was used?

Why are Newton’s rings ycnk ls7wie ):q-ert.u0ym3p3en(z/(Fig. 24–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen im3y m7y.s2*p. mpznj by reflected light. What wavelengths do you suppose the coating is designed to transmit coj.i* 2m. pz mpnm7ysy3mpletely?

A drop of oil on a pond appears bright at its edgesmi+bgb3 l.6y h, where its thickness is much less than the wavelengths of vis3 gih6.+ mblybible light. What can you say about the index of refraction of the oil?

What does polarization mfo5.mdhwzjnwm2,9fe(i(n)f7 q5fx tell us about the nature of light?

Explain the advantage of polarized sunglasses over normal )1ugz pdm-cy( tinted sunglasses.

How can you tell if a pair of s;kjk3sg-b83czytq6n5i xd8 b unglasses is polarizing or not?

Two polarized sheets rotated at an angle of y/p*p0h k5t::ti n-rls axmk .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 thewhq 9)x0lsyh*9 3seaf Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it ieleq9:* 2opn h7xtgfy0(/ afzs, would sunlight still be white, or would it be some other 0 zo:x2(f/h *nay7qpt eg9 felcolor?

  Monochromatic light falling/ sq k, y3o-r *old )vo.13zsksgtq/ud on two slits 0.016 mm apart produces the fifth-order fringe at an 8d-g/3o*rlutvz1doqks)so 3s, /q .ky.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 angle of-yop(oy5 rkggmpgboo/ ).1o0 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on 28:( / nry uhd:l5lzv khxiur9two very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 mikx8rhlrvu / 2(h :nd9y zu5l: 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 from a He-Ne la,x h 8:v4exagf/jxci1z so6 9bser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the c1eosv4ifa x, x6 cb 9xz/:8gjhenter of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits anv+mttj;s 70ah h, ri*ud 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 separation of the u+hr0s thvm;ti a*j7,two slits?    mm

  If 720-nm and 660-nm lig1;ld2 inzo) ysht passes through two slits 0.58 mm apart, how far apartl2io)zy1 ;dn s are the second-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of uyr1 ; qb:j2s/q*4lxj )rpa vz4knn*twavelength 460 nm gives a second-order maximum at a certain location on the screen.ax4*/14tybsvnzu:;*r jlq 2)q krpj n What wavelength of visible light would have a minimum at the same location?    nm

Water waves having pars1czi+*ohl1 :ektw 6dallel crests 2.5 cm apart 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 “straight-through” direction wousl61 zd*ewi1 +hotc k:ld there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower slit in Fig. 24–45pfmiw*x 8d:ony7 gx 7 so thapoif4xn5mg87 y wx*: dt the two waves enter the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the third-order maximum for ltr ac0cw,:jys 1.y,sxight of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the sec,rwjcxstc.s 1y, a0y :ond-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. F::kr b9a: djxmind the distance between adjacent bright fringes on a screen 5.0 m kmxr9 aj::d b:from the slits.    mm

  Light of wavelength 480 nm in air .d1bs ; ud6fnofalls 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 double-slit apparat nr r( c5 hj3u4szf1e6hg37iiuus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minh3r(sir 3hcfj u e4zg7u 561niimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red7 :)lasa(ng5 wl9,s1 nqrhmdcb s/g s. light (700 nm) exceed that of violet light (400 nm) in silicate flint glasscg9gd 75.w l) /b r,mnsahssa1 slqn(:? (See Fig. 24–14.)    %

  A light beam strikes 0w*enl1) w:n6ggq cxy a piece 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 containv*acld r* n/d;,,o eu,q hrz2oing two wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm wide, what is typ zh/ m*9yxl+he full angular width of the central dy *zx +mlp9yh/iffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit zk.;z.(9zvybx6kabj dagf- 9that 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 s9.p oit .lt)5z+xxfly)ll (tb6po4f$ 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 width ofri( kr.o94/qparn1ox the central maximum (in cm) in the diffraction pattern onka1nqo.( xr 9/pr4i ro a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a sliz9-. cplmc t 7.vaetl3t. If the angle between the first bright fringes on either side of the 73tta p lcm..zvc-le9 central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffractsl6fyqlu.28 ,jsi 1xp4xa.e yion peak on a screen 2.30 m behind a 0.0348-mm-wide slit il4.j , xl2y6iqp8xausf 1ly. esluminated by 589-nm light?    cm

  When blue light of wavelength 440 nm fa9 qmf )3z t9c )zk,ref9sdce.slls on a single slit, the first dark bands on either side of centes f39z9dreezt. )qkc c,)fms9r are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelengcc .rki7ezw b**doh0 .w:h +qeth 415 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen thaokzcb*c7e i0h.w+ w*r ed.qh:t is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 63wa 6 (x rg62kdz)vadgnmmhfrq53.q, 50-nm light so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum fov mrddnfq65 ,.63)2qxg mza a whg3kr(r light of wavelength 420 nm?    cm

For a given wavelengt k;kh ozrf)6r:l2 o 1rglze)eb0)l5jf h $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 5639*)vuxaw 7cf an5 (iic7vsat0-nm light produce a second-order maximum when falling on a grating whose sliisc3a7aacixf(u7nv 59*) v wtts 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 gratv1x qg r+9*jf2w1qwx ting have if the third-order occurs at ax9q11xgj *fr+ 2qtv wwn 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 a diffraction gratiz gru(-a0ootk+)vh;m oy 1y n3ng is observed + ohtv zo ay3yn;0g-ukr)1 mo(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 /mpy rs2z6m8 ral8 (tn6eylxqhs:2 v:$ 6.0\times10^{ 5}\;lines/m$. Find the angular spread in the second-order spectrum between red light of wavelength $ 7.0\times10^{-7 }\;m$ and blue light of wavelength $ 4.5\times10^{-7 }\;m$.    $^{\circ}\,$

  Light falling normally on a l h5tdxqu)(ek z2;p/x $9700-line/cm$ 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 a grating with 6000 linq lten*d;l)4m es per cm is illuminated with 633-nm laser lindt* le );4qmlght? Assume normal incidence.   

  Two (and only two) full spectral ordercu r0y d;jtz21qqoom/n (s ,0hs can be seen on either side of the central maximum when white light is sent through a diffraction gratin /qhsotn,(r 0 zuy0mo1 2;jdqcg. 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 f0c nrz2 r,6bcegrj/rw t/5gko5)9z pmalls on a grating with z rcwr25on b56)/rztkj/gepr0 g ,9cm$8500\;lines/cm$ 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 wavelen;oe2-(m x1 qk 25zwgkxf m/v9;ayzabugth $\lambda\;=\;6.328\times10^{-7 }\;m$ 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 spectrumipb se 4-+/dfd x:ac4a lines 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 120 nm thick, what a bt)9jzur zbu 5f),vx*10z xdwavelength is most strongly reflected at the center of the outer surface when illuminated norm*ab9zbu, )rzz0x djxu)f5 v1t ally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Examplekyy8p r euwv20-z+(rx;l wyi; 24–8 if the glass plates are each 26.5 cm long? (w +eyk yuryril wz-;p2x;08 v    cm

  What is the smallest thickness of a soap film my s/*mt n:78 npb5hph$(n\;=\;1.42)$ 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 greeni. vt1-si*e3os ie zmc5sh yellow ($\lambda\;=\;570\;mm$ 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 darkr+y6pqgjf ,q v l:.aw( Newton’s rings (not 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 (Fig. 24–31). How much thicker is the c lf.+qgpwaj(,:q vyr6enter than the edges?    $\mu m$

  A fine metal foil sepa2i g9*)9ro7mdi ybtknrates one end of two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 9 kyrdt)2bi9og7inm*28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between tyl:6d-ek 7cx 8eeixcorl (/h)wo flat glass surfaces if the glass is to appearxhe7ec/xroide k 8ly6c)l (: - 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 diamond askhv3f /5qs;$(n=2.42)$ 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 )cyjkb(7* wrbin :8cq$(n=1.36)$ 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. 24–3n*dwsv mbfxs; *3t*w91) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index9wf ;*dxv*tb*snw 3ms of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 brigq1h 1is.; 1zx y/u) u3fi:npgp,dbkkqcbse6 5 ht fringes are counted when the movable mirror moves 0.22f hdyqbeqkp,5u gpsziki61 :xn1;1/3.)u s bc 5 mm?    nm

  A micrometer is connected to the movable mirtif jm84xqe3 b 3res.5ror of an interferometer. When the micrometer is tightened down 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 foil3te xbfer3ijs 8.54 mq? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirb;vqq4 fjkgj w5u1* y2ror $M_1$ 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 (Figieb-f-qozglp /mrj t:bi ( 05gac )*9e. 24–59) passes through a small glass container containing a cavity 1.30 cm de/ge *:rp-z9te ab i5ji)- g bmco(qlf0ep. 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 oriented at kc dz;72 ay;+2t bxi8kj*xtp,bwd 6hb65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air 4gcy xlnt +7sws2/y-g–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle fo7g (e5sflol .ar a diamond submerged in water if the light is hitting5e(o.fs a g7ll the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passingjs)hg rzgj92cb( ij+3vhs ay f222uz1 through them is a maximum. At what angle should one of them be placed so that the inh2jy2f+jh1a)r2 iusb zs2g 39czjvg(tensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle shouldpkyt1c fg 5fjenz *(;+ the axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized lpc ;(y*zf5fj nkeg1t+ ight to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orie8hn g6 :( s)7ehxrk2mys rs;btnted 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 at50 ijiwg5/5 f8x 9uauh+wrvjv 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 u2q h8 i-c,+nz, jxw yaoifc-2surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the2+f, q,8yjxihzc-- uoaci2wn surface.
If the light is coming from water to air, $\theta_{p}$    $^{\circ}\,$For the refraction at the critical angle from water to air $\theta_c$   $^{\circ}$ If the light is coming from air to water $\theta_p'$   $^{\circ}$

  Unpolarized light passes through five successive Polaroid sheets, each of whoc*6i cke m.rq,se axis c. ciq6emr,*k makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength z kcb o:lb t,jrt(c9/n5g.y2 s$ 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 wavebn2horw,b 3 m/s reflecting from mountains or airplanes can interfere with the direcwro 2m/ ,n3hbbt 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 seppyi(pa 9u,m4d +1te o2iab97y5dlxh yarate sources passes through a diffraction grating with ti7 abyie5, lpo2 +yyhmpu1ad94(x9 d$ 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 4 td;ey-t mrytu3 .td6)1+ nmomi b8se0.60 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 cet) m ;eeryy8utb3s6t .mn+td-di41mo ntral 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 identical antrqf si,m c/(:r9:+py8hlfc zpennae 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 midpoint and extending horizontally in both directions. If the midline +/i: hscc98lmy qrp r(z,:ffpis 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 doorway 0.88 m wide+1:5pu(a/ xpap-u*iqgs la lfww,k9o , and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not iqpo(w1gfap:ua +9, ua-w *5pslkx l/ 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 e3ay2 p4c gubx,0jv .j4fas6 jof width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beet/w b2o ie( ja e(0je9 *t3ljp*q2lh4wc wrg0kvle have a series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright whe3 *iej 0t9 rceqgh 0pwl(w*(l24kwev ojj2/abn 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 be no second-obc cw:)ht)g i*nswgn )rusb0.l +a 66hrder spectrum for any visible wavelent*):+snl6w 6auggbc0.)sh in)hrbc wgth?   $ lines/cm$

Show that the second- and third-order spectra of white4) mjur2kic:g ztcmnfet368 7 light produced by a diffraction grating always overlap. What wavelengths overlap exactlctu8 3 r427mkf ng ej6t)z:icmy?

  When yellow sodium lmh8yw33otno 27ghx1reuac-9 ight, $\lambda\;=\;$ 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 m)teyn8awj5g*cz-t8 viewed on a screen 2.5 m from the grating. The incident light beam consi5 egnay *)m8wt 8czjt-sts of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clear material if a minimu,x(de w *4vkc0mp2kwzm of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choi wdx4 m*(,pvzkw0e 2kcce for an answer?

  Monochromatic light of variable wavelength is incident normally on a /zth6xgnvr) ycm ; jtt6lj7 --hfga (-thin sheet of plastic film in air. The reflected light is a minimum only forz-l - t n/ht;x( hc66gj)7rjvf- tyamg $\lambda\;=\;512nm$ 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-reflective co*zi km *euj/2k1mk rp-6lg7amating $(n=1.38)$ applied to a glass lens in order to eliminate
(a) blue (450 nm),    nm
(b) red (700 nm) reflections for light at normal incidence.    nm

  What is the minimum (non-zero) thickness for the air layer between two flat gm.mml(j n,9hz lass surfhz ml9mj.(n ,maces 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 throug + eyzo:3tf0(y x(l e+whse)cch a thin film layered on a flat piece of glass. Draw a 3++xoc y w:hley0zs e )etfc((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 to zero.
24-30
24-36

  At what angle above the horizon is the Sun when lm5./c y b-olj rs zpy639a+svxight reflecting off a smooth lake c s.b+ s jv 3om5/az-6rp9ylyxis polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polar axnsw/s . v4pmsviyhu5* ma,(h,z);aoids 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) of niys)ps,vs/m hwh, aaux5;z amv 4.(*
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axes are aj5(oan/5ap6 dc lwfj9ml0 v) ut right angles. A third polarizer is placed between the fi6 lj5)/jmf95oavc( lp0 naudwrst 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 placex i uyq9;e4 f5g6zb;pzd in succession 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 1vre 8u1wqi(5zz.u e+ i8z5jqc.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of e +cvj.(qrizz 5q8ewu uzi518wavelength 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 2 /),zccikmrj are 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 l tpkydka 3 ,rc4,(e3k$(n=1.34)$ 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 radiatin0 vuog.y.ps2b -sal;h:k f j2cg 6.0-MHz radio waves in phase with each other. They are located at points. c.o2k-yb2 ugv:;lspasfjh0 $S_1$ 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 650 n:, j-ade9bvz(,iab( wk ggvt(ag*6qsm, enters a silicate flint glass equilateral prism (Fig. 24–58).gd9e6babjv:z(aq- ,i *stav(gg (k, w
(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 or dkw0k76pxsz*q(j5 d ne flat surface 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