Does Huygens’ principle apply to dkk5m oax ,s57)5vlbn2t ,d fcsound waves? To water waves? Explain.

What is the evidence that light is ene z2gj3 vl ;xuogah.p 1 dhlrc:z:9(nuf g-zd6:rgy?

Why is light sometimes described as rays and sometimes as wavenbh,.9qxj9qmvh)e3 j-tg* s gs?

We can hear sounds ars8woe xtse +-7ound corners, but we cannot see around corners; yet both sound and light are waves. ss t-wo7 ee8+xExplain the difference.

If Young’s double-slit experiment were submerged in water, how 7zgk2a 7vb0 xi7qibaprm4z/bs t8o.2 would the fringe patti a0bzz ai7g.xm/bsq77 r8tb o2v4p 2kern be changed?

Monochromatic red light is incident o9x/2g* :yy-lg e1cf(rtiozf en a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source1lzgife9txfo ey(r2 cg/y -*:.

Two rays of light from the zzy)2k 0p: kngsame source destructively interfere if their path lengths differ by how 0p:ygzz)k k n2much?

Why was the observation o 5*w 7 +chdjjot2senqfsi0z 4*f the double-slit interference pattern more convincing evidence for the wavt0 2 7 fji4+sw 5qo*hn*jdzscee theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for r8* wpl7-g rve-q,tmy light waves. Discuss the similarities and differencpm* lry7 -rt8g e,-qvwes.

Why doesn’t the light from the two headlights of a dist*7hh u 1b(b*jnlr-ut zant car produce an interference patter1ujhz n 7 (r-hbblu*t*n?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is cover60 mf:g+i8x0lv y 0dd /vlerobed by a red filter (700 nm) and the other by a blue filter vlbr60 mf ly:e800/ oig+ vxdd(450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of win;) -zdl1s gxkldow glass, it is not broken down into colors as it is by a prism. Explaiks g 1lxdz)l;-n.

For both converging and diveuj2p0d zs,y(qxl9tz*s 3n id 9rging lenses, discuss how the focal length for red light differs from yjqsn,spl 3d9z(tid*0u x 92zthat for violet light.

A ray of light is refracted through three differenta00byg ;e4fj w materials (Fig. 24–55). Rank the materials according to their index of refraction, least4e wf bj;gya00 to greatest.

Hold one hand close tx ek3 wq51qz*3lq rl( al.yd;r9.tq jqo your eye 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 you see.. dya l3lkz51xq;lqjqq93tqr w*r( .e

What happens to the diffraction pattern of a single c dqi6oz,z zk747z(-7hwqapy slit if the whole apparatus is immersed in (a) water, (b) a vacuud(qz-q7hwzyko,cz7 za 746i p m, instead of in air.

For diffraction by a single slit, what is the effect of increasing +t c8 jz*7iful(a) the slit width, and (b) the wavelzj+u7 8*f ltciength?

What is the difference indgc7 7 kuy65keejs) z. the interference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what iobj/g k a)sgura;uin6 b e/nuc2/.n14s the advantage of (a) many slits, (b) closely spaced slits2aika;) .1bnuuj/e c/rbongs g nu6/4 ?

White light strikes (a) a diffau +m31vm)o j tnl+n)0 tkfq5rraction grating, and (b) a prism. A rainbow appears on a wal q50+nokftmral vu 3m)+ 1jn)tl just below 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 betw2db(s ue * :zuaavbnu14 g0g9xeen 400 nm and 700 nm, incident normally on a dsex n91(b0z24bggu*a:da vu uiffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin 9n14z82w-l(c6 qcrnm svahehfilm like a soap bubble and notenza2m(18s hc4c9 r lhn-wv6q for a thick piece of glass, say?

When a compact disk (CD) is hel2jghz /cn d;1bd at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you exp2jnc;/1hg z dbect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer to,0t36 e;0x2z9wv0 tlitjii x zf hbwc8gether farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What9t0+5x yr ed(hrb a(r6fbbu8i wavelengths do you suppose the coating is designed to transmit comrrbh+ 6i8 bux(t 9d0arbey(f5pletely?

A drop of oil on a pond appears bright at its edges,:) 0 j+d*lnfvyiy 2hzh where its thickness is much less than the wavelengths of visible lig+ld)2y0*ynh fj vh :izht. What can you say about the index of refraction of the oil?

What does polarization tj7 uj ( wssgsw,3naz,9ell us about the nature of light?

Explain the advantage of polarized sunglasses over normal ti6 f)wotqiy4by;hc4: lnted sunglasses.

How can you tell if a pair of sunglahds,; p(u cvb.aa;j*q sses is polarizing or not?

Two polarized sheets rotated at an(t w7.+vgdow hcx la:+ 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 thf0eg0 7e7 kjk-ogsk6:qwmyr )auo-r: e sky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser lq- /ofsu.am0than it is, would sunlight still bea f./o0mus- ql white, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces tfsti, xanfkx s() bt/l8b204yhe fifth-order s20fxsit(4 ln)8/abbyk x,t ffringe 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 sw4r5v 7r (9vcvi( bhqangle 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 nar*6r4ga7 1kosdy 1vsxzs0db k4row slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength an1zvkkdrg*sos61dba0 y 7s4 4xd frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laserjc)lb45 fkod+, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart.okcb fl+4d)j5 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 tftj5xt; d7k2 falls on two slits and produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m t fj2kt;d5x 7taway. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm f oj9b:k mco4-apart, how far apart kfo ojc-9 :4bmare the second-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is j- .x*1*bwc2 cmao ds w:x lcu3/v(jgmfound that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the cl( m jwg21-*ca/ d.v*xcjw:3umsxbo screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm ail0r:jw,wa n .k5axr*vdh.*cpart 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” daichxrl*dk wvw.n0,5r. :a j*irection would there be little or no wave action?

Suppose a thin piece of glass is placed in front of nacxjzcluu;20cm )y) +*k(:emne kj(the lower slit in Fig. 24–7 so that the two waves enter ekaneu 0+*jlx(y;2c) n jk()mumcz:c 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 ;3 ,vupo3 7g:(g jh(m qqdgb elks1.bdmaximum 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 the same slits. How far from the central bright spot wilg q.3d7((u,pd:vqm;g1 bskb3 jeo gl hl the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illum w dlcn6tbtd4npn1:7;inated by 544 nm light. Find the distance between:twcpt 16n;d47 lnbdn adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 n2qt0qr2 guwt .m 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 dki 6fryjhap1k ,nlf*)p43/xa double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a ma n4h36 1krppal,f)iyfx */kjdximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed thxhllidlkn8u6g/g n 5d eo-7y h9337 zzat of violet light (400 nm) in silicate flint glass? (S 56lh7h-7z3kduo3z /ldng l ngx8 9eyiee Fig. 24–14.)    %

  A light beam strikes a ba3qy( su.l .bk7iog8 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 containing two wavelengths, hzto+mb7j4kx91f 5i h-7k ry e$\lambda_1\;=\;450\;nm$ 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 0.0ez ozz i ()tqi(1kj0v0440 mm wide, what is the full angular width of the c0 ztoz 1iivzek() 0j(qentral diffraction peak?    $^{\circ}\,$

  Monochromatic light fnu u.wy2sd05nnh 6hr 2alls 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 fal/ brd-kc -,kutls on 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 wide:zu;8uylf kj9 is illuminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a scru:uz8 l;ykj 9feen 5.0 m away?    cm

  Monochromatic light 4 x(8idd uz)xnapfx*/om 86a hof wavelength 653 nm falls on a slit. If the angle between the firu io6fn(hp/d xx *xmz8a a)d84st bright fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffractiltxc d94n4fc nmx1 -z5on peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 5144lncm 59 f- dnctzxx89-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, theef(cf9pw(j ( 1fk*tm;8koj q i first dark bands on8kff(wofk; ctjq9i j*pe(( m 1 either side of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on 9:kx;.hismz bky/ l-tr.2hfea single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that ihtksib- h2e. fx .m9 l:yrz;k/s 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so thatr18t*o,i9to k4)p )ecn:gi qrbhl0 gr the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the widthg9otro e):0qir1nplrt*i)h8gb k,4 c of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengths+v 9dz-w(/s gb k6e 9lrjm;ql $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nmv1p8b) ;0hj*y1 svp)ojx* zzgik7zu l light produce a second-order maximum when falling on a 8p*1iyvghj;)k lz )s1 px7vz boz*0j ugrating 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 gy:-;fd 8l s1okbgykifhw s* *9 ofq51hrating have if the third-order occurs at an :1h1kgl 8*do b-s9ffy kiw;fso q5h*y 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 lightizc+f)cr)y8cc u mr ./ falling on a diffraction grating is observed at a 15.5)yz/) . r r8ucccf+cmi$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratin4 g) b3,eayldlod80t jg 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 normally on a 3 jl 5 iqo2ep3cdcy8e6$9700-line/cm$ 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 i8pv /i3in:xh 6000 lines per cm is illuminated with 633-nm laser lig inh8p/ ii3xv:ht? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on hczt 3p/ogmue*z;m+0 either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating /z* e0hpo;zt3uc+m mg?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to:qqyx 5i1yn4j k3pd y( 750 nm falls on a grating with :y1 yq y35jdn 4qx(pik$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light85o,ipov bim. 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 are measured byh +/y2xa9s,v/ h *ujv gtsaz8m 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 wave4 rapt wp xlgh/qd4*om 21/z* 7t6evvblength is most strongly reflected at the cenvp* ld7/agtm xh4/vo1 qwe6 r t2zb*p4ter 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 Exampldi 5c npd o0;lq-gwf:1e 24–8 if the glass plates are each 26.5 cm lcod0f;wpnl 1-: ig5dq ong?    cm

  What is the smallest thickness of a soapo z. mn l ghoh:yujh -(ukd2pxd.5/b8- 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 greenisf nu,t :1f4j o8 rocb:,-me0gvpblzj: h 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 dark Newton’s rings-o0 j+)ru9 f5anoykhnjjego +j2c9v. (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. 24–35jr)j.v+yook0+jug9f ona29 j e c- hn1). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of opticalai 7k9avukg98ly flat glass, as in Fig. 24–339kka9va i78 gu. 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) snk hokab0t tmm s-s8a.: 3yl-:hould the air layer be between two flat glass surfaces if the glass is to appear briab.an-k0k::-3hm lm y sstot8ght when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspd, t+7d u4auhlected 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 alcohol dr8 agav5y7jj5ll i- 2$(n=1.36)$ 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–k)guwkd n4/foi 5t/t9nsj0,f 31) is immersed in a liquid, the diameter of the eighth dark ring decreases fromtjk0wtf4o) 5snkdf/nu/gi9, 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength os h(6nx, 3frlsf the light entering an interferometer if 644 bright fringes are counted when the movable misfl ,nr6s3 hx(rror moves 0.225 mm?    nm

  A micrometer is connectedmti1 mwg *yqvxd4z8h nvtdkbu0- ) ):/ to the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer, is 272. What is the thickness of the foil? The4:nt*dzmwq1yi dvb8uk -)xgtvm )0/h wavelength of light used is 589 nm.    $\mu m$

  How far must the mir nou5zxuzoic2 *a fkh3*plhj*- (,j8pzz-b t 2ror $M_1$ 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 interferome4(fkd-u y :locj 4bxs-ter (Fig. 24–59) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allow bs( kyod:-4u -4fcxljed 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 orie+ewpw q0y;*iw nted at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angl,;e ; 9/u phftz+azofme for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the ligvy66(+cw uwkf n/p n8nht is hittinpw6 nnkf yuv8/wc6+( ng the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing tw + k +su fb,d*1g2nz8cjhxm8yhrough them is a maximum. At what angle should one of them be placed so that the intensity is subsequentbyfwjg8k8*zms2 1c+,d+uhnxly reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Po7 ;hl 9a4e1j xkm;xptolaroids be placed so as to reduce the intensity of the incident unpolarized light ttxma14;x;k p e9oh lj7o
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orie6 r+u ivob*ph(y5 ssz3p ;ef+tnted 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 u(f0bx7 s 3* (c.xeuhkzewd(qat 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off the surface of water for ligh 2gcqs jckkt e(,o:t12 *auiz*t coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface.k (ej:12 *kctqogsc*iaz t u,2
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 passe e,yf0hai) slg7q rd/1s through five successive Polaroid sheets, each of whose axis ma 1eyra0qf,id)lsh/7 gkes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength /*/oran,p e- 3tfsi8 t dcv80qeln,rt$ 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 ;fb u2lkhdji 4: ,e2gafrom mountains or airplanes can interfere with the direct signal from the station u ai2egbhdf,j ;:l2k4.
(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 7kx7 lbjo7t0k5t6h n othrough a diffraction grating with o770txlb75ojkhkt6 n $ 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. T;m 1ese9ps,gyj(ai v6he screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the c ;p6i(s1,mja9s veegyentral maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 n3;mf;ayzie ( MHz broadcasts from two identical antennae at the same elevation but separated 3e a i;nyz(mf;by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back from an out-(6 d:mbt gotzside 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 w- g6tzm t:(dobhistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit ohmhqjeq.wi w3p9:y )4 1t/a*7d mx jugf 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 aufwb ej -3;qo s.six7:/ r5aqvh/f2 cscross them. When normally incident 460-nm light is reflected from the wing, the wing appears brc /jqa35:sviw.q uh;obxss72- efr/f ight when 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 nj7haa/+ whf b;o second-order spectrum for any visible waveh wb/ h+afj;a7length?   $ lines/cm$

Show that the second- and zep i,c+dl0s1 third-order spectra of white light produced by a diffraction grating always zcd, e0is +p1loverlap. What wavelengths overlap exactly?

  When yellow sodium lzqn4.drs7pe +gry4yt: ;u 9fcight, $\lambda\;=\;$ 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 gra;dr7 /ka-a0gfd8py bt ting with and the pattern is viewed on a scr gya a-7dp 0b;rt/d8kfeen 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 wv 365xikfh r3ntywd64 wo3f)clear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce rey)34t x3 53rfh6 owik6dfwvnwflection 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 normally on a thin sheetb t76 8ova2wjj cupap55 r0vb2 of plastic film in air. The reflected ligh2a5bu76 p8 jt rcwoja0vb5 p2vt is a minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an anti-whft1ggoa7;/jx 6 o2;dhda n8 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- viy6mh gn;0 yfw*gz78lf31 orzero) thickness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm liggvhf iw6g o zmf 7;3*rnyl80y1ht is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film lafu2p xm8i3 -o9*ys/qwm 7dvz uyered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative size zqs97-of/ vud*pm yx 8i2um3wof the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun whef cjcp r:f,a *n ),1y.6a orsewps9ob:n light reflecting off a smooth lake is polarized most s 6:acrrf:b ,w,9e)fcp s*sa.1opyjn otrongly?    $^{\circ}\,$

  At what angle should the axes of tjdu,ih):; bhywo 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) ofy ,hdj)ub :;hi
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheet0tq8o(l, mt wms whose transmission axes are at right angles. A third polarizer is placed between the firtw8m(0, olt mqst 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 suqvi 6 cyzuq9i7a(r* /vccession 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;k,)6.z pkr4opfmgo t of width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km frof.pkop 4,mt k)6 r;gzom 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 polarizers;bopx 4la6pmz 5h*qe 0 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 i*a7nhp sx/7t$(n=1.34)$ 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 radio b; 4bnalke6 p:jk0f2gn.m1opwaves in phase with each other. They are lo ;of1ng0624p : ejkabmnkbp.l cated 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 wavelen;ryv 9+o+wwknicfej dq5 s z 64v0l( n7x(j3ljgths, 420 nm and 650 nm, enters a s o7y iv+sl9f jz6(x qjckn ed( n+w0r5l3;vjw4ilicate flint glass equilateral prism (Fig. 24–58).
(a) What is the angle between the two beams leaving the prism?    $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with    $^{\circ}\,$

  A Lucite planoconvex lens has one flat surface and /vhp 7mvfp7 mjh2o9f 5kcng2 1one 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