Does Huygens’ principle ; 9q.9sfo ,1ji onbbfqapply to sound waves? To water waves? Explain.

What is the evidence that light is kym+9w7z )tv c2or n5renergy?

Why is light sometimes described as rays and sometimes as otwsu3 2n t4d2k(if3xwaves?

We can hear sounds around corners, but we cannot see around corners; yet both p:np z*,p 6eo5awad *osound and light are waves. Exadop:n ,e*pp w 56*zaoplain the difference.

If Young’s double-slit experiment were submerged in water, how wouhp4hg4s3;13m9 lt aaoa-bosi ld the fringe pattern be ch3oiho4g4a-1s;t9h m aa3blspanged?

Monochromatic red light is incidentsflov uc5f( 4gp8zg35 on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the 8ff3u p(g5vcs4g 5zol fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructivm5q+)g rq)mxpely interfere if their path lengths differ by x)gr) 5mp+q mqhow much?

Why was the observation of the dou,l6yzzc gjy -9 lh6x4fble-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffracgz,6y 4cy6hj9f x-zlltion?

Compare a double-slit experiment s,.ex j5jhb,- fuxifp/o me)9 m 6)qyj:ksd9nfor sound waves to that for light waves. Discuss the similarities and h6.xk , imu:y5f-fj dme9j9/no pe,qsjs xb))differences.

Why doesn’t the light from the two headlights of a distant car produce anehc (tp1dz(m-j;d b,i interference ed p-bc mh((izt,1 j;dpattern?

Suppose white light falls on the two slits of Fig. hhejc/ 7,-utumqy+ *3vn+mv y 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 scr*hyc t/+uvv3q7 m ,u+jy-en mheen.

When white light passes through a flat piece of window glass*5luxau:.s+ - l, hhv: tuk8w auxvrh), it is not broken down into colors )h5au: hk.lvlu- *v+sxu:h8 x w,utraas it is by a prism. Explain.

For both converging and diverging lenses, discuss m- s)8(xhorwn how the focal length for red light differs from th8 or-()hnxwmsat for violet light.

A ray of light is refracted through three different materialsb+f ;,;c4gq hv3v awmsznx.l1 (Fig. 24–55). Rank tzq;lx.sfv gb ,; 41wvmh+c3an he materials according to their index of refraction, least to greatest.

Hold one hand close to your eye and f,h(8rbd4 ;4 ltklgzp+gb1/kccb o dw;ocus on a distant light source through a narrow slit between two fingers. (Adjust you8 lk4t4 / h+ 1gbblw;k(cr;o,pgbdcdzr fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a singl0j/b 2wl+0kqqk(sjt j, 2zofre slit if the whole apparatus is immersed in (a) water, (b) a vacuum,2 qqf0+k j kbzsjt/rlo,0j(2w instead of in air.

For diffraction by a sid6 54tkp.f )o 6www epyert1ix,sr( 7tngle slit, what is the effect of increasing (a) the slit width, and (b) d41w, (x5t6o. es6yrfpww7t )e kpi rtthe wavelength?

What is the difference in the interference patterns formed (a) by two sl4c)*7z8b 1ftu q;ff o cnvx6yoits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what ib:ejkhxtz cfu 72k. 40epuzf.( w:1z rs the advantage of (a) many slits, (b) closely spaced slitf::4 wu71 .xkf. th(0kzbuzjc rpeez2s?

White light strikes (a) a diffe t8z* -9t *zq9jkj:lmh po+ykraction grating, and (b) a prism. A rainbow 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 e:zj*jm y8+lzk*pqoktt h9-9 each case? Explain.

For light consisting of wavelenywl2/22 vq 7aiuxpr3ggths between 400 nm and 700 nm, incident normally on a diffraction gratinr2 w27/ugxvy2q pil a3g, 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 fo cx8 c0zk :louwtmx(pcg b / n)q(-map3j+fr,)r a thin film like a soap bubble and not for a thick piece of glass,-acuf ,pq)pom mj l gzw( c)+n3tck8b0rx(/x : say?

When a compact disk (CD) is held at an angle i9cck5c m 4ea09qkk )mgyb- 2ktn white light, the reflected light is a full spectrum (Fig.kgc c0m2yk9 54k9k-bma) cteq 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer tx1qf2-dxya ; rogether farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. Wha i3izu.t+t cwv*ep.4q t wavelengths do you suppose the coating is desig.cq ie3w zuivp+t4t *.ned to transmit completely?

A drop of oil on a p22 7hrn,tfzx oond appears bright at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of refraction o7xhn22 ortf, zf the oil?

What does polarization tell us about the nature7bi:8 9fpt+alodzsl z ks3x1- of light?

Explain the advantage of polaeqv( k9z nk;9brized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglgr .s3c)wahx+ asses is polarizing or not?

Two polarized sheets vsq8w,pik+d 6 :6+oxn*z ykviufmo 4( rotated 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 Earth had nzsj)8;fwu,m do atmosphere?

If the Earth’s atmosphere were 50 times denser3 -:khx/ms pol than it is, would sunlight still be white, or would hm-poxl/k3:s it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart gxg k mgeqh(q/(.w v6e92*rtt produces the fifth-order fring(vgqe9x/mgtk h2 e(qt rw.6* ge at 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 a7 hmie53 rfbq32 lib+cj,egl *ngle 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 m/i3snt ucho68m apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength /it6 uho3 8scnand frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a Hr)ixe8 at94i-mn vo j-e-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of t-mjtoix84v)r -en9a i he pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm tqd)fy5 mr : qqzoa;;-js8;kk falls on two slits and produces an interference pattern in which the fourth-order fringekdof; q: )z8 qj mtsqk-;5ar;y is 38 mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm ce +8jk7ubr:e light passes through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 me:cu k+je7b 8r away?    mm

  In a double-slit experiment, it is found that blue lumc ; b+m)bip5ight 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 lo) cb;m +mb5iupcation?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings 5.ju n/n 9k a*yst+:ion+m73 egnm;-ow e0 cm apart in a board. At a point 2.0 m beyond the board, at wun+nt*i 9knwo o+es7; ymg:n a -mj3e/hat angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in frop 4xxmna3t1x 5nt of the lower slit in Fig. 24–7 sonxaxt5 xm 143p that 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 light of wave)f-oq,z uw 0jef x0+q w1v+pfalength 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 second-order maximum of this light ba-) z +,1off+w qwupjqxfv0 e0e located?    mm

  Two narrow slits separated by 1.0 mm are illuminatit, yw p-p2) zjv;an7med by 544 nm light. Find the distance between adjacent bright fringes o)-t ,m z7vppj na;i2ywn a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on 1umcp o v)q bbk3/b4w4two 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 plasekn+g3 2r8p wu.)b5n9j*r rl h2xmybntic (n=1.60) covers one slit of a double-slit apparatus illuminated by 6jb5ukyr2m*.rnnhwlxegpb 9r2 n)8 +340-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed -.pikwvs nxcvf9-. vmm-4r3qf.;shf that of violet light (400 nm) n. cq.9vkx ;pi3.s ms vwf4-vh-mf-rf in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60.avc i-p;k79m + f;pxua00$^{\circ}\,$ 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 lightkpg4wegjok :y,yz7q 8)(x.:p vfrw6 b containing 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 se)hbwvkuh(9- ( *ai5ps( vyttlit 0.0440 mm wide, what is the full angular width os (tyviptk u-*)9h( a(h5evbw f the central diffraction peak?    $^{\circ}\,$

  Monochromatic light izc bz3q jjcokdp7+ ,( dqi9l.w(t) 5zfalls on 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 ) n: ndcawai33is $ 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 wizwsy6mhn3spd 5 48imfqi: 7 tzv9)0atdth of the central maximum (in cm) in the didyant qm 5is7hsz3wm 9:0fp i)4v zt86ffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on axo0n (7l;msbp slit. If the angle between the first m; pxns7 b0l(obright 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 0.0348i.ktnl6 (y : v,/og70s3sj q brnvd8ce-mm-wide slit i 7nvns e ty(/,qljov3k .68gir:0bd cslluminated by 589-nm light?    cm

  When blue light of wavelength 440 nb szjt7h *dei2u7v2 s1m falls on a single slit, the first dark bands on either side of center are separated*72ejvstbu1hi s7zd 2 by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls oln e 2td,r-a2obvcs4n x)/z-in 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 wide is the s d/n22-io,na-) vl xt4bzesrc lit?    mm

  If a slit diffracts 650-nm light so that rchgx /ef6-p. the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction g6rep -/xhc.fmaximum for light of wavelength 420 nm?    cm

For a given waveleng f ce9 0*ox3-cyghty(oth $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light pr k 8oc-.y4kbqdoduce a second-order maximum when falling on a grating whose sbdk8qk-o y.4 clits 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 i6utkp; 7xwd)s s a5t:qf the third-order occurs at an 18.0xs76tus 5 ptdq:w;)a k$^{\circ}\,$ 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 grating is o bnb , 3y::qccsyttx k 8jy(zb9f3.xu:bserved ( bzy9 sbttu jkcyx3y.nq :b8x:cf:3, 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 nq.+ so7 m 06hqd,ihs),xl rqc$ 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 normallyj*wbq k* ;.enf 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 seep ;e,ao 0t,0pcajgc)mn if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assumecppg t )m ao,0a0ce,j; normal incidence.   

  Two (and only two) full spectral orders can be seen on either sir2oa)juq5sf 0 :efhwy5lkw:l /sw . :pde of the central maximum when white light is sent through a diffract5.aww:)kjoufl: :q0ws2 pyeshlf r/5ion grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a grating with 8z2br6n ef5h zibe;qmn*bv)( bfih*n(m 6);5q znvb28ee zrb $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromati(5( qjdq7t)w8yb ih tpc 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 spectrumv)b0 ;8 dggj8kvpqy8i -d9num 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 wavelength is48cqw6i8c: l:esw r1g1 uwo qt most strongly reflected at the center of the outer surface when illuminated ge4 8 8 :q owi:srlw11tcc6wuqnormally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in E+yd, b apn .tk89f: m5oqucg:ixample 24–8 if the glass plates are each 26.58, yopa9dgbq c5fi:utn.m:+ k cm long?    cm

  What is the smallest thickness of ag/4g xk6oyz 9wtqot*7 soap 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 1) j0hheirm9lyellow ($\lambda\;=\;570\;mm$ 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 (not6pz )gvea3gbh. eu*y ; 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. 24buggpy) h*; 6evez.3a –31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optica)yw j 78 ymhwxw0 9h8:;9honxmwp(ftally flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observet :oy8ax)y8 nh m7wp(m0whw99jh;wf xd (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass surfaces ifwdpun*hbd b:2b 37:u nhvf1r. the glass is to appear bright when 450-nm d:fndbvrw27*1. hph:uunb3 b light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen diamonszylk 67 3zyj,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 alcohowsug5:ub(*d)8scn*gw xm : icl $(n=1.36)$ 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-n)s;sk) sdr0kk vq*j apparatus (Fig. 24–31) 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 i; kvjksss ))*nq-dr0kndex of the liquid?   

  What is the wavelength of the light entering an interfero zzk)/-i23v4dvh*o wi4;t cshvn ;klumeter if 644 bright fringes are counted when the movable mirror moves 0.22 /3kvsdzi vku) hhcno*42;; 4lizv w-t5 mm?    nm

  A micrometer is connected to the movable mirror of an intz hzrg :r8afm;-,:sb kerferometer. 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 foig 8-:h s zrfba,zrm:k;l? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirron.jjx.z 6 8d xg, dgdr:y;xb2or $M_1$ 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 53jaz sf/ vst or,)om cztw12up(0bu9 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 nmvj 19 cr3, ztap(2z)uu ts5omow/0b sf. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 65o b6y2zgl4,gs $^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an aio;t8z9hygeax 3h4x*a 8pg:l y r–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged it9yk rpk+y5un8q)*ujp,j/)vnm-u e zn water if the light is hitting thek/9 8jpuu-y, q j5*)ypkurevn+z n)tm diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that , p:fw(yqa9 ,-becgllthe light passing through them is a maximum. At wha, la,9pge fl-c: y(qbwt angle should 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 so as to re.kqxr1f60 ctqx do9fn*x d6 ,cduce the intensity of the incidenxqd6dok nt x.c r0f,9xc*q f61t unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orv,k2 ri(fnlj 3iented at 40$^{\circ}\,$ to each other and plane-polarized light is incident on them. If only 15% of the light gets through both of them, what was the initial polarization direction of the incident light?    $^{\circ}\,$

  Two polarizers are oriented at 38)p0::f 7/9.wttapo-gsdf ak+uidqe o .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 water mhc3 p(u)ny+u4 5uikc for light coming from beneath the surface? Compare to c3p5)+i uu mny h(kuc4the 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 successive Polaroid so4n) na 3gxw,mv8a ci5heets, each of whose a84a giwx5 o), 3mnvnacxis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength d*r8hqgpl6 io9ck+ 3t$ 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 ,h(b0ug(s yg rw :cg1ninterfere with the direct signal g1ru hw0:b , c(gsng(yfrom 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 th+v/,qh4a jf6fel ;q5wx; csy4 p3ivnvrough a diffraction grating with f+ep fj; s 3,xv4 6hl;y vinq5/4vwacq$ 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 ffru.xk 32 dl.pzb01+ty xc6p 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 central maximum than the 590-nm light. What is the wavelengt0pfbyp+c12r36x . td ufkxlz .h of the unknown light? $\lambda_2$    nm

A radio station operatindc*nvtzlu6)9/ ; fc lbg at 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 midpoint and )nbc6 zcv utf;*/9ldlextending 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 doorway 0.88 m wide, and blows a 95xq7-ndoe+ jf 4e kta0cw,id ek -ym(whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground outsided45t-(wyxkcme-di 7 n9e0j k +afe q,o the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falga(235scnbzr h y;j 6lls on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across them.4h b5dg g;5vssw j.nw3 When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an anglebs 4s5n; g.vgww3 d5jh of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is tov/;;uhsdf; uqh6t2 da be no second-order u hhd/qf;d2a6tu;v;sspectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by a diffrg v 6h(n-qx3f8qn0lobaction0hx l bfnnvq3(o6q-8g grating always overlap. What wavelengths overlap exactly?

  When yellow sodium lix*s..gr*z0twl8ci qe3 yb0 5;wjn ilkght, $\lambda\;=\;$ 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 iz 2d .2djxamn(s viewed on a screen 2.5 m from the grating. The incident light beam consists of two wavelengjn z2(.dd2 axmths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 minimum of 1a0au24venzp j,.av:v50 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 cp .unj va20,v4:vaazehoice for an answer?

  Monochromatic light of variable wavelength is incident normally on a thit 1mw7am., hwcn sheet of plastic film in air. The reflected light 7,mmwa w h1t.cis 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 neede;35/v q qj4tbsn.vee;q+ ze(cff0ynsd 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 fobtqb9w;z5 ql:bij27azv)1 /ac d 5 wxdr the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm 9 ;zz t:qbjwiwd/5v2ba)xq1bl5c d7 a light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thk 2op0kb bw ;) wdy/zpknufk8v5du-- 3in 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. Consider all poss2d-pw- u5;bk)3zknkf o 0uyvdp/kw8 b ible 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 reflecting off a smooth lh1; p*o x,qdzmake is polarized most strongly?x,z1;q* hompd    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placedf)ofmg jp21 ng-wj bkl32w(o 3;h5plh so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts hb)p 2;j3w2pf1- 3nfwg5 ml okjl(hog it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two v5z dt1)l(pmhybh q.; polarizer sheets whose transmission axes are at right angles. A third polarizer is placed between the first two so that its axis ma;)tbqhm5y zp(.vd hl 1kes 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 success7bcb9 z:ga*l y l8czwv7:-lbl ion 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 1.0 cm and is etg/p5kk -cui(j9 5c)r ,rnblpointed at the Moon, which is approkgkn j )b/t(ril uecp55r9,c-ximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizerd6xweko5 ayl9/ 9q8f hs 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 8;chxm*b arg)0xi qn f to01)dq*p9 qn$(n=1.34)$ 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 1xc2)+ym fkm:hpps(/ j zzv;p radiating 6.0-MHz radio waves in phase with each other. They are located at points)yhsc;kvz p1( fj2 ppmm/+xz: $S_1$ 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 nm,s -99c 8yidtr *tf)fsc enters a silicate flint glass equilateral prism (dt9s9fcy r-* )t csi8fFig. 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 wih4p1 j+6y d:xrfa )ouith $R\;=\;18.4\,cm$ 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