Does Huygens’ principle apply to sound waves? To water fh vy v./: :;7fpm zry23uludswaves? Explain.

What is the evidence that 2c07erv.w o ayp-db-uo;ho2y light is energy?

Why is light sometimes described as rays and s5n:un;i bg7c vometimes as waves?

We can hear sounds around cornerjy1 76 kd8)mwxunou+kw*lwo*s, but we cannot see around corners; yet both sound and light are waves. Explain td 8*uwwj1 xn7koo wu6lk)+y *mhe difference.

If Young’s double-slit experiment w o*)u .;eogcoq*jwyaq 9yhh-(ere submerged in water, how would the fringe pattey)h*owjq(ua9 o y*.gohq c;e-rn be changed?

Monochromatic red light is incident on a doub0dp 3 knf*j:gele 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 replaced0kpgde* nf3 :j by a blue light source.

Two rays of light from the same source destructively interfere if their phxb81hucq/ v zovb80pq p-u:1 ath lengths differ by b xhq1p:/bqh 1p0z-uuov v8 8chow much?

Why was the observation of the double-slit interferenceqpju-xjo;r5g3 ;yt7 v pattern more convincing evidence for the wave theory of light than the ogpy5u-;o;7vtr j3q j xbservation of diffraction?

Compare a double-slit experiment for sound waves to th8g:gjrwrzlo, bzh3kct 8. ,2f at for light waves. Discuss the simi,,.t:88b2zo j gh zwcfrr3g lklarities and differences.

Why doesn’t the light from the two headlights of a distant cty jsp(v:k *,k80 df tvqu;1rdar produce an interfe*jkk t8rtp f v,q1ds:v 0dyu(;rence pattern?

Suppose white light falls on the two 7(riekatt08 ).rqqcz(qm j 9vslits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the7t8t9 )e0mqqrcr azqj .((k vi other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes thr7d-z8a qk r-(,tr))gnup5 g;m hopw rfough a flat piece of window glass, it is not broken down into colors as it is by n-fhkr)5 trzwar - pgo(m8q,)pu7d;ga prism. Explain.

For both converging and diverging lenses, ft, nmzx)-e3n;u:f badiscuss how the focal length for red light differs from that for violet le:;nb )ftn3-a zf uxm,ight.

A ray of light is refracted tvf;7 o:bi,/v9bp)ft +uy c vqy( fsle)hrough three different materials (Fig. 24–55). Rank the materials according to their indutpfve b/9+f,c ): (ivvs bqflo7;)yyex of refraction, least to greatest.

Hold one hand close to your eye and focus on a 8bgv)6gwpm b sw2h:8 udistant light source through a narrow slit between two fingers. (Adgsugbw hv2):8 6w8m bpjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pata3mb i6 ( t(lsmz6o,uqtern of a single slit if the whole apparatus is immersed in (a) watez6 (6m,msi lq(buto3ar, (b) a vacuum, instead of in air.

For diffraction by a single slit, what mtz/4xa *+ cctis the effect of increasing (a) the slit widxc c/t+z*4atmth, and (b) the wavelength?

What is the differencef5ea 0e(cnka9s v41nj in 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 the advantage of (a) many slits, (b) closeltpq r,mj-c fxcs 2n (i*c(*a8ly spaceq-mjxc2( *tn (p*fci cras ,8ld slits?

White light strikes (a) a diffraction grating, and (b) a prism. A rainbovgew2z . 90n;/joitss *ol7r+vx m me0w appears on a wall just below the direction of the horizontal incidentl o0m.mwsn09etij+/v z*r g7xv;s2o e beam in each case. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incident norm2v rn; i2 objz0ut1mdp:ut )0jally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the sd2jn z ;rovt)it0 10jmp: 2ubulit spacing?

Why are interference fringes noticeable only for a thin film like oi( ; : cpoj tll4os a0q*dzo+36vz l9s6-uxqta soap bubble and (*l;j0tsulp436+q 9q6o sc tv - xlzaz:oo odinot for a thick piece of glass, say?

When a compact disk (CD) is held at aqgfc/kvhry6.z7:f6s,q ,e lysc hh+ 4 n angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What wo f + h.467sr,yqscckzvfhl:hy6qe /g ,uld you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fa-it*0ozaki -ynx f0 v7rther from the center?

Some coated lenses appear gzflku t,.50xsj vk 7 ljm7,jg8reenish yellow when seen by reflected light. What wavelengths do you suppose the coating is dm7tj7l v.gxj,kusf085zl j,k esigned to transmit completely?

A drop of oil on a pond appears brig unvj /guo p.b5-k*k.ettep30ht at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of re*pk ge.unto0bp j. v/ e-uk35tfraction of the oil?

What does polarization tell us about ag: b)mt+(p:5rlz q dwthe nature of light?

Explain the advantage of polarized sunglasses over normal tun-cu 1lqix.t2 l0 (nkinted sunglasses.

How can you tell if a pair of sunglasses is polf vfj/k)do, q1arizing or not?

Two polarized sheets rotated at an angle of 90x: cnq )s ka05m 3 0tvk;h,8hh s2nemqap25tzx$^{\circ}\,$ 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 atmosphere?w9 d) iyodeq0:bm1/ik

If the Earth’s atmospher )tho my.oz/y9c i-/jn ,g:xqre were 50 times denser than it is, would sunlight still be9 yoc,o) ri x :/h-qg/j.tnzmy white, or would it be some other color?

  Monochromatic light falling on two slits 0.0di-x1,guna9c w+h m* x16 mm apart produces the fifth-order fri xxgi+*w- 1 9,cnahdmunge 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 angle of 18,rhwxb 1kcp4v /;cd(s$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two ve(r)edg 2j.dtv ry narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6 dg)jev2(.trd .5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a waveleng ya*.s(wdo w-eth 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are o ae-w.swy(* dthe fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and produces antp, s8jg w*q1 )6r0wsh dhes0m interference pattern in which the fo*w0s)qjrews 8h,d0p gtm 1hs6urth-order fringe 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 light passes throbc7 .nvwst+d8ljemc** kt.z4bz/: jough two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 m away.k/veno*.swzt +cz bbtj*: jc4 8 7ldm?    mm

  In a double-slit experiment, it is found that blue light of wavelengtd;+y6v: + )phlfho;c:b zl usxh 460 nm gives a second-order maximum at a c+c hps:)oy;; +d6f:vlxluz bh ertain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 3lmhf,cl (/kz 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “straight-through” direction would th /zf(m3hcllk, ere be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower slit in Fig. 24–r:hdoo+e.n7.)7 * v qihg*bvqllu1z j7 so that the two wavesr olh1l7 vh :jzv)q oqdi*ng7*+.. eub 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 lvdy9 7ym,p6/z bgyp9j ight of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the6gd,/9yyvb9 jpyz7 m p 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 by b rynb12z k6xq f*br5gc0dz:f588vjn544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from k d r 1 fzc:n8*fz8xyvb05qn5g6jbbr2the slits.    mm

  Light of wavelength 480 ,dhrxuz w2;adzp29 fl x+ck/o0. sd,onm 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 plasfom,84ignkfo 7 8 dep/:ed q3n e5wvo7tic (n=1.60) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastiqog43fv8:n,edomp5n e7kofe7 w /d8i c?    nm

  By what percent, approximately, does th8px, )cdy9zoxnjbnu * :6 og/pe speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fino,*9)/upco8 6j d:x ygzpnbx g. 24–14.)    %

  A light beam strikes a piece of g)vyp e(s: oleg86o2t6 1krcn.0pmqc id6u,hvlass 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 wavelenwzy ,naw,x1asy;s3 - dgths, $\lambda_1\;=\;450\;nm$ 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 ang/th2ywvedrpgz::x( 0ular width of the central diffractionpr2dtxg0 : hz:(y/wev peak?    $^{\circ}\,$

  Monochromatic light falls o3n 8xc ishbi+bz8zv3 9n 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 fp.e0 /x 9(7hhgfwdihwalls 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 is illuminated by 450-nm light. What is the 9q +7 ndzneq:77ao: )n:4debshtqbj m width of the central maximum (in cm) in the diffraction pattern on a screen 5.0 m away? qj:n7 ebsze):+ dt:d 4q mnoa7qb9h7n   cm

  Monochromatic light of wavelength 653 nm falls on)wu0 r he).eqx 4qun y9n*bgm) a slit. If the angle between the first bright fringes on eith urx y) 4e)enq)9n*mubq.0hg wer 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 e+0d,g p oey4cbehind a 0.0348-mm-wide sg0eydpo4,ce+ lit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dar8 irwrcw)-o dp, h/8jek bands on either side of center are separated byh)joc8e-p/w r w8ird , 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 z5medd,jvu 4(p(1k ozn((yyo nm falls on a single slit, it creates a central diffraction peak that (pozjy den yu14m 5dk,(v((oz 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 li7y;8x wiuxd/gq7 :x fhght so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction ma;d7w78ifh qxg xxu:/ yximum for light of wavelength 420 nm?    cm

For a given wavelength w.eft rs gx;r 9vh2tt:(bv, v,ftp(e,$\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce ax:o57 onjsrzmb)hzdc*ntn05g k 5 00d second-order maximum when falling on agrhnzxst 050jbzom o0d*n)5:c nkd 57 grating 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 grating1x p(m,, o7xulywtb+-okl d k; have if the third-order occurs at ayp +ool 1m l ku;,wbd(x,kt-x7n 18.0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

  A grating has $8300\;lines/cm$. How many complete spectral orders can be seen (400 nm to 700 nm) when it is illuminated by white light?   

  The first-order line of 589-nm light falling on a diffracti:xrtg5vu( 5 ux-uyo byj (d.)fb/,otuon grating is observed at a 15.(u o, t)btodr5:uyjv -(yfu.x u5g/xb5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating ha azuei.o.(l (k 0ypa1e3c lq3jr7 )mfjs $ 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 i6: 4ac.zq bkka $9700-line/cm$ 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 tg*(sfl( yz /axv14dand ; hdl9hat can be seen if a grating with 6000 lines per cm is illumy4dsl (/ g* znflx 9v;1ad(dhainated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on v2h(/dozja:d)u (m 89pmqy xseither side of the central maxid os() q audy:mhpx28jz /v(m9mum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containinj0a- c( w .ldixjvgeoig87 30zg wavelengths from 410 nm to 750 nm falls on a grating witha-jwic3v7( gg0zo0 x ljdie .8 $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light of a knowii-;, p7d13awih bllfl 73zoe n 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 measxw0dikckxnj/ke nd r(f7b8-7 xf9q. *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 wavelength i)+zfwxg49zd 8+vt krj6 ) tjsms most strongly reflected at the center of the outer surface when illuminated normally by white light? Assume that dxsm8t9wzg k rf)zj46t +)v+j$n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass platf ks4mz cupm74; j/qm*es are each 26.5 cm long?4cq4j*z;/ umpm7fm sk    cm

  What is the smallest thickness of a soaig8tine- x82sx6i av.p 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 mntn) uscs:k71m 2cm*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 (not counting the dark slp2y ow09 mfku,.m fkj,7prr. w)qii.pot at the center) are observed when 550-nm light fall.qflojr20mw kyu.p wp,m,.fi )9i r7ks normally on a planoconvex 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 59ja y cpr9pl:one end of two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). c5 pp y:la9j9rHow thick is the foil?    $\mu m$

  How thick (minimum) sh44fffi at :rm3ould the air layer be between two flat glass surfaces if the glass is to appear bright rim43at4ff f:when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of beig9iyi/c 9lnq8z ,iz 93s0+qo4 bvsa fgng 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 alcoh d 8g0*9aoyrnchl1mg9 3t:wpmol $(n=1.36)$ 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 (e)-+rwec;k*cwa b; fcFig. 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 r)fa+rw* c wb; e;cke-cefractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if obl4t9/n.8rqlrycw9v 0gl y/644 bright fringes are counted when the movable mirror moves 0nglrcoyrtlly0.4 9b8w / 9/q v.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometek3 /zmlk4b)91l fk2y(yyeb 9ypj 2qpsr. 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? The wavelength of light used i1yj2p b k)3l9ym9ykqe2 /fs zp4 bkly(s 589 nm.    $\mu m$

  How far must the mirrob6/62(l l2shivy ekyq r $M_1$ 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 interferovnt*4*8irc:-uy q lqemeter (Fig. 24–59) passes through a small glass container coq 4c:qn8-v*i*yel rut ntaining 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 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented *bvw+wnp/8 tm at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle fo8mq)sh 8coa; er an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is hittiny9 glxd, lxfi(:zb)7cg the diazilcxf :)bxg,(d9l 7 ymond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through;m sq 7eag(i;nb ;hc;x them is a maximum. At what angle should one of them be placed so that the intensity is subsequentlyx bmh;7a;cei(sg;nq ; reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plakug:9yn,y z(je m.p8fced so as to reduce the intensity of the incident unpolarized light tz ug8m yjne:y9,. (kfpo
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orien0ytj2/puk 9eu50ho i eted 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 orienk;4 :b9ub-4wtuzpn zc2y0k i ated 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’(hocbq67 s.u os angle be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total interno6o(.q s7u hbcal 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 th :qa vlqbbs))35uh5fy rough five successive Polaroid sheets, each of whose axiulh 5 : b5vys)qabfq)3s makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength fe6zmque (2g1 $ 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 59tdb a f-g3vbu-bx+ev/snh+ reflecting from mountains or airplanes can interfere with vx+ sb+- 9bengtv/h b3adu5- fthe direct 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 separate sources passes through ad.sndn qrtl93)yiq0u c -7m,a diffraction grating with cu q9tn my0,.7sal q-d3)rdni$ 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 narrovgvlumzyt w2-.j , x7dmt601d :xxk2xw slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its sec6um 0zjmd2kvtlx.wx 2 7tgvy1 ,xx:d- ond-order fringe 1.33 mm closer to 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 identicvc7th xi2:ml6c(3i rixl6 zo9al 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, i 69 mcv2i o 3z6:7hrxxliclt(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 outside doorway 0.88 m wide, an5nougswh g wh :o5;hpp3)n i22d blows a whistle of frequency 750 Hz. Ignoring reflections, 3hw5p;h)i : 52nn2googhupwsestimate 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 slitt(s loq 0jy*v53 ;ylwo of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetlel5x(m q c e yi*le7lb+.ug:dwzji:)3 v have a series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appeaxll)(y3d5 l:vg +je *iimw.eqczb u:7rs bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter qz ysur300/s4h c)sdymust a grating have if there is to be no second-order spectrum for any visible wavelength)dsy sr 400sh/qu yc3z?   $ lines/cm$

Show that the second- and third-order spectra of white light producedw;72b +-xygfeyl9 knea5n0 ry by a diffracti 2lx;59gyk7bfewyrn-+y0 enaon grating always overlap. What wavelengths overlap exactly?

  When yellow sodium lzv vu,a4 (h7tzight, $\lambda\;=\;$ 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 viewed ort:3 0 g h iotpx2*vh:zur:)sln a screen 2.5 m from the grating. The incident light beam consists of t* :0h)otlt3p 2grz uhsr:i xv:wo 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 q8mbwhm 7 *g5kif a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to kq85mhm7 g*bw nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wsj5r;lbg 4/h lavelength is incident normally on a thin sheet of plastic film in air. The reflected light is a minimum onlbl gh;5l/ rjs4y 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 f cc9nfnk :8n:tor 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 bw- ihha: ,,kd( fa*g gzcrr(p2etween two flat glass surfaces if the glass is to appear dark when 640-nm light is incide g wzga2ap(h* rdichf,:(-k r,nt normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the l7ai/0 (kkcmw1y;q h bbight transmitted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–3k/w7 ; aq iby(b1mkch06, 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 tlcw0 t m/ ,ej4z7mw3aqhe horizon is the Sun when light reflecting off a smooth lake is polarized most stronglzw7m0 ,4atqj w/eml3cy?    $^{\circ}\,$

  At what angle should the a 05nllgw 0hb)jxes of two Polaroids be placed so as to reduce the intensity of thb l0jn 5l)0wghe incident unpolarized light 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 two.+n8 ,gv s8nwazttj:r polarizer sheets whose transmission axes are at right angles. A third polarizegnn8sz ,vj.8t rw+a t:r 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 successi5tj9 v .er4,2ayzl nl8gj8 hglon 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 and2p r+-/zt ;wm wim+(gchkj+by is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red lightwb(zm cy/mjw+h+pt + kr-2g;i of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each place3s2 a4ukohv ofn(;so ,d 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 tw l3 i;,oypk6(*bktk$(n=1.34)$ 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 oam pq 8ol0*dla; 4s/fssj7cs.ther. Thpafc s *.840lsa/7jms;o ldsqey are located 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 wavelengthe -vr:iv 3xkd+s, 420 nm and 650 nm, enters a silic:v3rx+e -ivdk ate 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 oh*s y-4sm2 7i: e/nrj4rxtjyune 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