Does Huygens’ principle apply to sound waves? To watb(, uto) g.kdxer waves? Explain.

What is the evidence thczav n d-97;wdat light is energy?

Why is light sometimes described as g8 e3 chlc /qt5ctig,.+yp/nbrays and sometimes as waves?

We can hear sounds around corners, but we cannot see arounz(,c:i pevt fxld:p* ;d corners; yet both sound and light ar*c x,piled;f(: :tpv ze waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how wou0g 4b5 38--qyrpxdd5nzel yhfld the fringe pattern be b5-38d05nzglf qyyedrpx h4- changed?

Monochromatic red light is incident on a o, t2s wts)gd6mrf3 n9rls)- ddouble slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the re mrrln-s962fd t3g)),sw tdo sd light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if they gfawmxtr:5+qou):ob) at0; ir path lengths differ by how mt)fb0) wu rtgy:oaax: m ;5qo+uch?

Why was the observation of the double-slit interferei:z d078wgn2c9hyfmjteqo5w a+0 j23+oe ql cnce pattern more convincing evidence for the wave theoh+ofq8ecnt0 0g oy 7q 5+jd2 awim9je23zcl:w ry of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for light wav2nv y 76/lhqzses. Discuss the similarities and differ2lq7sy/ hn6vzences.

Why doesn’t the light frombh ird*n lmyj+ q8hs6n5qv(ulpb:mg-.ia03 1 the two headlights of a distant car produce an interference pattev5(:j -hds iu.nb mrll hgy+n 1ia80qqbp6 *m3rn?

Suppose white light fagf ltn1t*s4 o*3e nu*rlls on the two slits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). frn1*3 ol nst**tug e4Describe the pattern on the screen.

When white light passes through a flat piece of window glass, it is not pqv 6nt7b+l+bbroken down into colors as it is by a prisv+nql 6 tb7bp+m. Explain.

For both converging and diverging lertf 9w. oc dv96lgz;7cnses, discuss how the focal length for red l67l9corftgw.cd z9 v;ight differs from that for violet light.

A ray of light is refracted through three different materials (Fi)zla-(efs*ehgx.*-bvg) xm h g. 24–55). Rank the materials acca)( *-fm h- ehlb.e)v*x xzggsording to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source through a t+dn0gxa 9xkpw- rxy-8n -2p:w, um kjnarrow slit between twon+-, u a-p2xk8 90grwdyw: xnx-kptmj fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the wholt3ee qp/ bsr3f(maw7 9e apparatus is immersed in (a) water, (b) a vacuum,sq3 bw9e(atfp/e3 m r7 instead of in air.

For diffraction by a single slit, what is the effect of increasing (a) the slit c+9s-hd( 8e(sfq8. hc skfpoqwidth, and (b) t9 -ccs+pff 8o d.(s8hsq (kqehhe wavelength?

What is the difference in the interference patterns formed (a) by twx1(4 (u5epbl rz(vdq uo slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the a z1yv8me3 2rrodvantage of (a) many slits, (b) closely sp18r3r2ym veoz aced slits?

White light strikes (a) a diffraction grating, and (b) anq 3dfk3zr.fa3figq 0j 20. zo 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 t3 j.qfgn zzq0r3id.fok23fa 0op of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm2 8ytct qyiyi9 lnpnl+ mh;p/h16dt.5, incident normally on a diffraction grating, for what orders (if any) would there be overli cllyyh. 2t;8m+n561 p n9hitqtdy /pap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like +d*ve c4:x +dpxcqw3sa soap bubble c s:xv+*d+cw3p e4qd xand not for a thick piece of glass, say?

When a compact disk (CD) is held at a r0u c y8/2rubatn9z6an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochrota6/c urn089r ybua2z matic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from tbli(b0+i0sd ocyqxac 58 e/2ghe center?

Some coated lenses appear greenish yellow when seen by o;((3mf l-dgam i /i oel3bdg0ar5-kereflected light. What wavelengths do yo db3;l(m l m0kioaodfggeae(i/5-3 r-u suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright ti3w9*fxl:rs at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of refraction ot 9 *wrlif:s3xf the oil?

What does polarization tell us about th6i)pgaqn g: z2:2n v2(yjg60evjsreje nature of light?

Explain the advantage of polt9 vnegpqtt p; 96vg:s9+jpj 9arized sunglasses over normal tinted sunglasses.

How can you tell if a pegc yrxmp47/l s .i6ws44ws:hair of sunglasses is polarizing or not?

Two polarized sheets rotate6o jv,agv4- zid 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 no at;n6 .nw44yb0q jlvj+i4 grccxmosphere?

If the Earth’s atmosphere were 50 times denser than it is, would sunlight stia/z7/hbx5o9) cpvkf ro d: )zgll be white, or would it be some okp)rac)bz: dhz/o9 vg/7fx o5ther color?

  Monochromatic light falling on two slits 0.016 m.ovh0nz.y d:4 2alh bmm apart produces the fifth-order fringe at an 8.yv:do2h .zhm4.b0lan 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 o*)aqd m4::py*ffj awf q4q w*pf 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.m3a8b l axpc4sbxp:d o j;9:x 30bwugm apart. Successive fringes on a sxda.bju woxbpb0g3 l a8;9p ms4:xc:3creen 5.00 m 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 likb wfc 68l n 4fk09v-4l;l mt)3ivcmvw3dq4n aght from a He-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 ctf6k q4lcvl )k;inw4b3-vmv4l83 a mwcd 9fn0enter of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and pro/dt zvhnz z588duces 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 shzzzd 8/t5vn 8eparation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.5:u 7 :qjmgir2zxbg z.b. uc;*z8 mm apart, how far apart are the second-order frim::2;izg x7*jcu. grb .bquz znges for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit expfvaq r/gj/ )1aeriment, it is found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. Wha1gaajvqf/ )/r t wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through yg8avl;v a,( rtwo 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”gl;av(ra8v, y direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower slit 5dk f,v:k8z dgk 8pg5hin Fig. 24–7 so that the two wave:k,k 88vgzdpfd kg h55s 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-o0e 2:kt -wdc .zv/wjaxrder maximum 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 throug .0j2e /wvcdktz:wax- h 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 by 544 nm light. Fiy(c7fzf t9w;z oe mzogp:u,+h1,d3uwnd the distance between adjacent bright fringes on a screen 5.0 m from the slits. +cwwfom,ut hy ,7zpe ozd1u9gf; ( 3:z    mm

  Light of wavelength 480 nm in air48jm,n :(kyv7c x7wa 4sarcft6fa 8ip 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 ae0 p6pco7v d5mpparatus illuminated by 640-nm light. The center point on the screen, instead of being a mape7c d0 mo56pvximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red lig3bpyt+2v.dbsck. a 1vht (700 nm) exceed that of b1v.yva+kt 3db.csp2violet light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at + p/nke4k oc- y.9drqzu/k6b ma 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 ligy) 77lhwdpqd8lfa 5og 8./u n5 owp)o+2g abolht 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 slit 0.0440 mm wide, what is the full angular widthk9jzj :ylrj1 : u 4 xvlaoh::hr/qog/1 of the central difl1:g/ uj :4:rkahlr9o1jxy:h/jqz ovfraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit thah*9nzst ;qp* jt 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 h ost4w)j ;-sga 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 is illuminated by 450-nm lighf9;;hdj/)f lez a) kxat. What is the width of the central maximum (in cm) in the diffrjlf; e)f; ah)xd kza/9action pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the an fh:zfyadv46o 5c4wh,gle between the first bright fringes on either side of the centr4f4y h z:vao 6dhw,5fcal maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 mta:x c-/oeq / papazdpw6/h,yc13kx , behind a 0.0348-mm-wide slit illuminated by 589-nt/ow 1c k :6/qceda,/zpyxaa hp-xp,3 m light?    cm

  When blue light of wavelength 440 nm falls on a siv3 fo ad2l,:9mjvpcrw )re/y ;ngle slit, the first dark bands on either side of center are separated b2e,ywj l 3rvvc9am /:r);pfody 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wo 3 *s/exjgjb5+,o /xx qzlrp7avelength 415 nm falls on 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,3 z xjooje7lr*//xgxqp s+b5lit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum is 4.0 cm wz)8.zgj lw* riide on a screen 1.508giw r)zjzl *. m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given waveleng/s orf,: eg- y(azn8nhth $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-ordee1 +hj65dma6ufqgh x1r maximum when falling on a gramg hux1f1 6aqe6h+ 5jdting 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 doefj/ g auy29wa6i+ pos(s a grating have if the third-order occurs at an+a 9usip/6ya2 fwogj ( 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 q :/y-.9f zapnwp gf-e589-nm light falling on a diffraction grating is observed at a9fz qafp.:n/e-gwpy- 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating habnjez)4vl/ ik6wp. *w s $ 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 .w o j 4ve7-di7-gbcpfa $9700-line/cm$ 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 sez2vp-gu 61jvzcf w:-len if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal incuv6 c-vzw2 1zlfj gp-:idence.   

  Two (and only two) full spectral ordvdg z-u ok2uwj;, gxe(k q3,sv5ph :o1ers can be seen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of linesd3qk zkuhvup, ogj2,x1ogs:e(vw5 - ; per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelen2fid:e2w;fu ;ia4 u esgths from 410 nm to 750 nm falls on a grating with fe:w2i 4ia2 sd;efuu; $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whic 0)vo hq4mt e f)/w/c58ljezcwh 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 lines are measxiw5ixnh*53dngg4 i,a ua45 y ured 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 wab48 ffsxr00p o zu3le4velength is most strongly reflected at the center of the outer su8sfeu0pl4bx04 zof3r rface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass plates are each.ka:n u u7g3hi 26.5.nhag 3ikuu :7 cm long?    cm

  What is the smallest thicknnqa2q. q.o xc1ess 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 greenish yellow ;(pdr qdwqkh6(3jj:v6kh 5f0 4dbqo w($\lambda\;=\;570\;mm$ 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 + icq+zwn4;rw- pi.bq31 dark 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 suwqzinrw +p. q4-+b ;cirface (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 flat g.tmkv(-ww2 qwlass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are o (qw-vtkm2w w.bserved (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass(o g1/dj u9zp9(dcm zi surfaces if the glass is to appear bright when 450-nm light is incidenicmpo ud(( d g9jz9/1zt normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen3:iqmydl8s 9nllmzs/b )/- prky r92 u 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 alcohs4u4 wcb- zl2col $(n=1.36)$ lies on a flat glass plate $(n=1.51)$. When monochromatic light, whose wavelength can be changed, is incident normally, the reflected light is a minimum for $\lambda\;=\;512\;nm$ and a maximum for $\lambda\;=\;640\;nm$ What is the minimum thickness of the film?    nm

  When a Newton’s ring apparatus (Fig. 24–31) is immersed in a liquid, the diameta( 2q 6:0j x5q;ywgrgu9cri tcer of the eighth dark ring decreases from 2.92 cm to 2.48 qc9qr5 tyjgwcr:2; (0u6gxia cm. What is the refractive index of the liquid?   

  What is the wavelength of thvh.rh k3eof7q7m 1xw: n1s6ule light entering an interferometer if 644 bright fringes are counted when the movable mirror moves 0.22563ewk:qu fs.m71rloxh1v hn7 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. When thedq5eir ;kjn-r6 k02f7mgi/b d 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 odi2ng7k0 i-6brd ej;q/5 kfrmf the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror 2jx-vnt (5t z- +yrkwz$M_1$ 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/pw and,hub7bm2 ya1y-0 /xcm 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 dapx/bc01b adwya2/mm n-yuh,7rk 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 oriq at9 xfve4 3wy(0jx )fb;)j02nkga rmented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle gq gmo:35)c4fi)qw h sfor an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle 2 u6mid nu9wma2n69dx for a diamond submerged in water if the light is hitting theix9au 62d m69wudn2mn diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing throudm4f*vdf 4q+ r773 j x+noflwugh them is a maximum. At what angle should one of them be placed sol 7qd+nrf3 v+*m 4jfd7fwu4 xo that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the int92 vg.i o3o,l thiks,rx1 6rutensity of the incident unpolarizeuk,xtt.v6sr2 iogo 93r,i1hl d light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are ori-j.apb dw/-7d7mu wfdented 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 orientou6 kfgtme7df14/w h; ed 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 off the surface of wlkc5iaxl g+*9(5ha9r )kpa txater for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface. ih5c*x lpa aklrtga59( 9+k)x
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 sheet+ls pcz.sk 16us, each of whose axk1s6uz+cp.l sis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 2-i -g (p3ofjazuk;d+y 8snpq r;eg27q mrd4 d$ 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 )wm y00wdbm) cvknqvr1v )0o+or airplanes can interfere with the direo)v ww )v1yc)dmrb0+kvmnq 00ct 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 separatmw vahk0e 9a:b.q dy71e sources passes through a diffraction grating with q.wav9ak1h:m7 yd eb 0$ 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 pa55hl 8fzkivrwc9b4y 8kx x-5 6imglr )sses 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 to5hk -iikbzx lmr8)c4 f9 5 8xwlv56yrg the central 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 ao r4(f4ksp(gm ntennae 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 is taken as 0p4fm4( rkg o(s$^{\circ}\,$, 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 g01ki7ynn -fcqko) gz 8c4ji0 from an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, es0icckjgon )yzg q nk1i -f0847timate 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 sz6iqm2xd1m m*ingle slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a se8 f pzyzpsk2;;sst+n) 8 ho4zpries of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at nss8ho4pz; ztp;p+2syf8 kz) 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 brr2qu1ft;w.6 (e z bdl*)qhd8zcm d 8se no second-order spectrum f tzu . 2m wed8rc sqdhql;6b8r(z1*fd)or any visible wavelength?   $ lines/cm$

Show that the second- aegy- pb0 8iz+znd third-order spectra of white light produced by a diffract+e8b0yz g-i zpion grating always overlap. What wavelengths overlap exactly?

  When yellow sodium light, wl2b/qi dvf.5, uqb) b$\lambda\;=\;$ 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 viewijf8jge0jzy/ (xo 8 f6ed on a screen 2.5 m from the grating. The incident light beam consists of two wavjyoj 6gz f8i(/ejx 08felengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 of5tkaxh +na (yxj2-zo9 refraction of a clear material if a minimum 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 cha9t(2-a nkx z +joxh5yoice for an answer?

  Monochromatic light of variable wav8any1pj7;fn,a o-wml elength is incident normally on a thin sheet of plastic film in air. The reflected lol8y;m1 aw- nj,af7pnight 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 ahvy*:r q4h w02sd/gtsn anti-reflective coating $(n=1.38)$ applied to a glass lens in order to eliminate
(a) blue (450 nm),    nm
(b) red (700 nm) reflections for light at normal incidence.    nm

  What is the minimum (non-zero) thickness for the air layer between two flat glaq6ahc-vrw b+ w2e.do)ss surfaces if the glass is to appear dark when 640-nm light is incident normawv6ewd. -q hoab )+r2clly?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted th2g+jqz ,k:7w o3 nuao e6wwhn7rough a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required 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.qn3h ,wujwow+a k27no6 ge :z7
24-30
24-36

  At what angle above the horizon is the Sun when light reflecting o6q xigq 3bsy1upd p:68ff a smooth lakpq b id36yp qsx6:81gue is polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce tz k.qyam),,biibs6: phe intensity of the incident unpolarized light by an additional factor ( az :bb6pm,iks,y)i q.after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axes arnbi.dj4b e6a +e at right .6b eniab+ d4jangles. A third polarizer is placed between the first two so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axes vdm7 qddsepy9 w,0;/2szsvhlk /zq l43ertical, 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 widt 2bzb1r9g wy39us4ys*jz qf/ mh 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth.rwujby b4*zfmy1 2/gs zq399s 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 are each placed at a 109qa/s9 wdhg1 u$^{\circ}\,$ 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 (uoo, idi;7sv$(n=1.34)$ 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 phase with each 6 q ;cqx4:a-z7zwpcgeother. They are l-pcx6 g:q; c7zzewq4aocated 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 light5l bvqqlje;; ++e0ey-koi l6 c containing two wavelengths, 420 nm and 650 nm, enters a silicate fliq lc;+yo + q5;veejlkbl60i-e nt 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 xa+l eb /sjh/1has 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