Does Huygens’ principle apply to sound waves? To wate)fdfbo0:1t01w bzbndr waves? Explain.

What is the evidence that ligh i/eyb erm/nxu42qh).t is energy?

Why is light sometimep*e)0 )o0tf i plkl/bccf-kd2s described as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yetne7fk7 /pc car/.)eo)ksoeo/ both sound and light are wo7e conpk/afoe.) /e 7 crks/)aves. Explain the difference.

If Young’s double-slit experiment were submerged in wat,je imtc7 ld*)er, how would the fringe ,7* l mjeti)dcpattern be changed?

Monochromatic red light is incident on a double slit, and the interferea-v(cc s:+um)dq-q5r m din,cnce pattern is viewed on a screen some distance away. v+: cid-)( qca- sm crn,u5qdmExplain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively inteuaqtd-s+ 1x4 2,pak-al qre lfe8d6x 7rfere if their path lengths differ by how q-s6le+aq f 47 ldk-21duxpta,a8rxe much?

Why was the observation of the double-slit interference patte9x1o mr :q3slaxfp4qz4u0p/h; tu9 pzrn more convincing evidence for the wave theory of light than the observation of diffracti99pfprxo1z 4 p mtau;zx s/u0:hqlq43on?

Compare a double-slit experiment for s)3omkqth 8u hc27aomvdbmdj+03a3.u ound waves to that for light waves. Discuss the scjm38mua hvd+q037t3 ku)2om ahb o .dimilarities and differences.

Why doesn’t the light from the two headlights of a distant car producg:d*ywq91 bxkn:)fx ae an interferen f*x)waby:d91 kxngq: ce pattern?

Suppose white light falls on the two s1.(s0 m 1 k//g-vnfm.pb-gy; uof fgiuqxug 3zlits of Fig. 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 o gg1u mzv.;bygm guf(-.k//o1i nuqfpf3s0-xn the screen.

When white light passes through a flat piece of /;c6hmw8-ugamfw ) qc a;out(window glass, it is not broken down inqw ach u fma8;c-6/ w;m)ougt(to colors as it is by a prism. Explain.

For both converging and 8no6hg0zg+ae diverging lenses, discuss how the focal length for red light differs from that for violet light.0go nehg6+ 8za

A ray of light is refracted f4xd1tky w6l+*wt pg 7through three different materials (Fig. 24–55). Rank the materials accor*y6+kwgf7w dt xl tp41ding to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source through a n: h o0p+p9mvvdarrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that 0dp9 v mo:hpv+you see.

What happens to the diffraction pattern of a single slit if t6h,xk 4uw4d zche whole apparatus is immersed in (a) water, (b, 4uwdxz 4k6hc) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing ,od((tw5fp.oyw-sv r3a5qk i(a) the slit width, and (b) the wavelengthysait-,.5 (r5kdfpo3w q (vo w?

What is the difference in :ri,c1h(qeo q/fb/fk 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 is tp. bce4 41nl.qlsvp)fhe advantage of (a) many slits, (b) closely spaced sll4 n1spv pfq.4elb)c .its?

White light strikes (a) a diffraction gratingz- g 7tvbz42mx, 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 to - mtxzzg2vb74p of the rainbow in each case? Explain.

For light consisting of w6a)v y2+u,foeojm9w rs om,c9avelengths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit s) 2vwc o,+u6,9m9ojoer ysamfpacing?

Why are interference friio k6tdjarl.j-g6v 1 *nges noticeable only for a thin film like a soap bubble and not for a t-lova1ijtr6g. *kd 6 jhick piece of glass, say?

When a compact disk (CDw/ 7 sk6xm/lv f7o;rtd) is held at an angle in white light, the reflected light;lm / owk7trfx sv/6d7 is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) clol 0k 5ulsiqdlo bvfk4w53c+0lz+ q5s.ser together farther from the center?

Some coated lenses appear greenish yellow when seen by reg3bg4/euwphg lg01.qil3 64)bh xgfhflected light. What wavelengths do you suppose the coating is designed to transmit completelyg43up /4 l1 hi0heh3qfgx6 gbgbg.)wl?

A drop of oil on a pond appears bright at its edges, where g/mhou7wpp 92k n8k(my)ay(i its thickness is much less than the wavelengths of visible light. What can you say about the index of refraction of the oi82(g7nhuym)ki/ pp yomawk9 ( l?

What does polarization tell us about the nature ot.de,p( u,d-rvm vk s/f light?

Explain the advantage of polarized sunglasses over normal tinted sunglasses.6b/: 4mnctb6 6vq eglb

How can you tell if a pair of sunglasses is polarizcumj4 xuv*5o )6mu0h king or not?

Two polarized sheets roi3db)hx92pkr tated 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-73y (gqp fkvr had no atmosphere?

If the Earth’s atmosphere were 50 tk2w kchj8 )sp(imes denser than it is, would sunlight still be white,2s8p wkck jh() or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart producek*m1 ivj i i8f8hg) (skgi8dp;s the fifth-order fringe at an 8.8v8jdi h8 ispkgm)8fik( 1g ;i*$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at ansp/ ;f0dnw- s am2 fr:i*.x 0puikw1zf 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 py(no m.s9( s/h qju5an7a+l wmm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determineaw7(us/ 9nhn+j.5ymasoql p( the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne lc; rnfe /adycm 4 4(tu kmu(4sxp1a;2gaser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center ;mncu44(14 /xyfea2tup s a;m(dkgcr of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and produ .2dn5pnkb4 bvces an interference pattern in which the fourth-order fringe isb2 .nvdk bp54n 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 light pash1v ..5vlsv67qnr nih ses through two slits 0.58 mm apart, how far apart are the second-order frin sq1h6r v75lv..nhvniges for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 n*8pnj sx0 xie31lai2lm gives a second-order maximum at aiaje0lpn3s* xi12l8 x certain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two o :c.3-kbpkk xln 47*f :lzoseapenings 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 would there be little or no wave 43aeskx :lk 7np lbfz:ck.*-o action?

Suppose a thin piece of glass is placed in front of the lower slit kic;ts.;iqss:b k) 5dbe3 g/tin Fig. 24–7 so that the two wavdctq:5k;s esktb)ibgi. ;/3s es 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 foy(xofi.: :g rsr light of wavelength 500 n (s.:orf gxi:ym 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 be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated b0 i9,s dytxw+iy 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the syx +9i,s di0wtlits.    mm

  Light of wavelength 480 nm 5kvstn 124 oqain air falls on two slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a double-slit apparanwmse161l9h bj;(is e0unl8 gtus illuminated by 640-nm light. The center point on the screen, inste1i e;nh8weum0(1jlsgb6n 9l sad of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed oo)ylej5 ej:z nl udgh-v.v 9ibxf(+,8f red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? ey oi)e8f,+vzh n.9-d5j vju:(l xl bg(See Fig. 24–14.)    %

  A light beam strikes a piece x/k;jp(k rpd0x4 f,zwof 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 thm 54aebm2 2yrwo 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 ,f-gh4lm jn74uq(2epqcxlx1the full angular width of the c2qhclu,plf ( mgqx jx7-4n1 e4entral diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a w2+ln4 t)qjjc .. 2jz8cd drfo6w:lx hslit 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 onzoy(6l)j2t rm7:ghe w 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 5b4 vt+q5cn iywide is illuminated by 450-nm light. What is the width of th4nb5y q ctv5i+e central maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If th ipuh( p481, ckjcwd;4jpiw e9e angle between the first bright fringes on either side of the centralij(ek dp4ji,8u1ccp w4phw 9; 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 0.0348-mm-wy cdbqy:1ee;;ide slit illuminated by d;y;b1 ee:qcy 589-nm light?    cm

  When blue light of wavelength 440 nm falls o5ibudlu/ 7ft,n a single slit, the first dark bands on eithetf/ du b7ui5,lr 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 a single slit, it creatb cy/+t.6 gz+lrln:fves a centrbvylgz.n :t6 /l ++rfcal diffraction 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 is 4.0 cm w,0ud 5y-)lpy9c ckocuide on a screen 1.50 m away, what will be the width of the diffraction maxc ky50lp -,uu)dcyo 9cimum for light of wavelength 420 nm?    cm

For a given waveleng .npp27iwf th8th $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 56w2uo7k;poj8 vn 3x5 soqv)h3t rxty8:0-nm light produce a second-order maximum when falling on a g82:j vtys un5owo o78x p);3x 3vrkhtqrating whose slits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a grating have if the thx0kxk6/ nt w:5:ox imtird-order occurs at an 16t:wx:nk/xm0k oxi 5 t8.0$^{\circ}\,$ 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 d3r0 r y8dpk4feiffraction grating is observed at a 1pef3yr d4k8 r05.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating hasyaxxo,yhw;ao 2li01n-xwq9i ( ht3e. $ 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 unwc +or6ecz jng dh4f:+q .;dd.y 5)non 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 c kf4gn2w i /cm-saw,n4jnr44gan be seen if a grating with 6000 lines per cm is illumii4 kgwn44 cfm-a2w,gn/4jnrsnated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of ptc,*yrg(cuiyk m u ,342wnt :the central maximum when white light is sent through a diff2iyru *tw(3kc mcup4,y ,gn:traction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containi4d wlq9w637ie4(-bp ez unnt gng wavelengths from 410 nm to 750 nm falls on a grating with ep79e6 w4lgz4-b (nuwq3 dtni$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whichoo:3 4 xzoknn/ produces monochromatic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum l0mvjw3)u r 4voines 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 n3/xs rqf ee.a, 3h4rpam thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by wsx,qfe .a34her r p/a3hite 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 pla2iu y5f 1m/ vb7ffeao8tes are each 26.5 cm lon7 imfyb8 2 o5ef1/auvfg?    cm

  What is the smallest td/3 t3kn roxx/yac10 zhickness of a 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 greenis6k+, *j) s+ yj7oujxlni /bzbvh 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 Newtnvlquaz ,d((kr5jq6+ b 4/t hhon’s rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvevl4( 5jza6n(rd/+bq,uhhkq t x lens resting 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 optically /hujvmmd5-d. z-:ey)rd x1)qlgipsy1)a i w. flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observea yp -1ei s.v.)dldu)5hyq)-mxmg r z1: jw/did (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between-u6/x:qgk -teje u;3ygyizkub 8y( y8 two flat glass surfaces if the glass is to appear bright when 450-nm light is incident normal8yygz/(- uyey3 8kbuxjg q: ut; e6k-ily?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stol;upn0 pvohf r 7i80* ag*jhi*oen 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 alcohop w/h(6kic1d v :4fhyql $(n=1.36)$ 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 apparat)ly uz ms2 .tm47b;hsaus (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm ;m.y2ztbs uh4 s 7mal)to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 v8v j5hx9of(ld*qv:h3snlb3fc ) x+gbright fringes are counted when the qjxs8(39vvhn5f vcxbh3dg l fl+o*) :movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror m,u2o ltz*/j(8 r3 )orqjzlpvof an interferometer. When the micrometer is tig(u zml2r 3r /lojq8o,tv)jz p*htened 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? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mir4hxpo *t63vleror $M_1$ 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 (Fcl8ensl+s*8c ig. 24–59) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted cse8lsn c l+8*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 ori( brn/o qg f20df 3hf7kb;sxi4ented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle f dp pgadm bkv1exv8(yntv,0.e 239 h/cor an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the93yrrd/x cbx0m/fs j; i tqy+3 .gg+ry light is hitting t rjy3qdis/ y g +0rfcx/yt;r+93bxm.ghe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing h14s orc+6muhthrough them is a maximum. At what angle should one of them be placed so that the intensity is subsequently c+o1hmh4u6r sreduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroidsnn:r4q*swi/mkt ;7f q be placed so as to reduce the int7krns w* nft;/ m4qiq:ensity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are or/3fuxwp w +/gwiented 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 orielq 30htz-kl /gsko8-.:sb b lvnted at 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections offujp9q20 xlew c8)kn2a xh m5l37fec j9 the surface of water for ligh9 nue2 80 59jxmklfl)w2pcj3xeh a7 cqt coming from 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 through five successive Polaroid stch v9fru)ejv: ,l-:bh9vc p,heets, each of whose axis makes a 4fhv e9:b vu-cp)t jvl, cr:h,95$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength vf;eg 0(ct kk5fqj,)r$ 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 interfere g mop3n sygmzl-*b*r wwq2-ch.y+4a8 with the direct sigh+nyqam s*gp wycm-28*g3z bowr .4l-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 a diffraction grating wi i+abk;f40shz th b+0izksa;4hf$ 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 590u 8*v*cyfet7uckj t gey :933s nm passes 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 3j*c csyv7k 3uf ee8ut y*:9tgis the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcamuxixr*s lo 1s7r(m20 sts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance mrr17* m2 xuilo0sxs(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 wel jxyb do-s+xtckn9:+9va2p 2wl back from an outside doorway 0.88 m wide, and blows a whistle of jk92y-+xtxcwsd+n: oap9v b2frequency 750 Hz. Ignoring reflections, estimate at what angle(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 sli *xnb3c9m nn//tuh,onz ih73qt 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 ac.xkv 37w.otwug s*zdv6b10 q dross them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an angle t ow0 qd7uw b 1*6vv3dg.xzs.kof 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if thern5m vxnp o17/ge is to be no second-order spec7n mpn/1v 5goxtrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light qb a7 qdb1*di-produced by a diffraction grating always overlap. Wh7q -qdb dbia*1at wavelengths overlap exactly?

  When yellow sodium light,qump: 2tz9(ki $\lambda\;=\;$ 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 difcr l.mw8w)xwi + 3sb;zrw5r12q nzkm1fraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of tinlw+ bzm;.c1k2wwr1 xz rr5m) 3sw8qwo 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 3.2is g u-q-c8iucptm a minimum of 150 nm thickness ocusg8 i mc-tip- 32uq.f 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 choice for an answer?

  Monochromatic light of variable wavelength is incident normally on a thin ,tk:i1 n*zr hkb, gni*sheet of plastic film in air. The reflected light is a mnk:*k1 ,btz* rgn,ih iinimum 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 thx (wf3u6/egmcickness 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 bee f9o .hlknl:3za7.rwtween two flat glass surfaces if the glass is to appear dark when 640-nm light is incident normallle7o9.h:z.fn l a kwr3y?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmittedmn /av1 js)f k/j.w4hn through a thin film layered on a flat piece of glass. Draw a diagram, similw)n/ .1j/4anmj vfsk har 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 light reflecting off ja0 c 00(iemmm(p2-w jowelp* a smooth lake is po 0ce 0m-j(mwjo *mlpewai02(plarized most strongly?    $^{\circ}\,$

  At what angle should the axes4y ph0hw41)p/woih bs of two Polaroids be placed so as to reduce the intensity of the incident unpolarized 4)/hbh0i1soyww 4h pplight by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on 2 v az89 gqhshnzxiezu61 l0-,two polarizer sheets whose transmission axes are at right angles. A third polarizer is placed between the first two so that its axis makes a9aq lxu ,i8snh-0hv g1zze 62z 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 placm ) ajt ip6a cz3-/lh.2jx0ycfed 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 1.0 cm and is pointch*fn5k 03d5 y 0xo1(kungjjqed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of(0kk0 qgn 53f1hox u*ydjnj c5 the beam when it reaches the Moon.    km

  A series of polarizers avtir/s )-e su*re 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 lme o0l-gkl+ar 8ol0ufov-4 -$(n=1.34)$ 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 waves in pg bnxu32yg. )ohase with each other. They are located at poin3 nu2ox bygg).ts $S_1$ 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 65v )x6ql / vgciky b6oqg3d*+q80 nm, enters a silicate flint glass equilateral prism8qqi)v/6l*3qxbck6 y gdo g v+ (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 leo w,( mx/x64mhrewb7bns has one 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