Does Huygens’ principle apply to sound waves? To water waves? Ex om00z1th1zavitvj;zg :z9+ c plain.

What is the evidence that light i1i x.i h07lyfis energy?

Why is light sometimes described as rays and sometimes a 5+ge ygq*m(p9qvv9yu s waves?

We can hear sounds around corners, but we cannot see ar;it bf./+af9msl8na)3s c htmound corners; yet both sound and)a sfthmn.9t/ifb asl3c;m 8+ light are waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, hofgykk:tal24 k e*;vrw1 j nf16q5/kqjw would the fringe kwn6j4 k2kj t*a;1ylqgfqf/ rk1v:e5pattern be changed?

Monochromatic red light is inclc cr m1oac13(ident on 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 ligh ca113c(lor cmt source is replaced by a blue light source.

Two rays of light from the same source destructively interfere zy/ a7ecj+lv .if their path lengths differ y.e/j+ l vaz7cby how much?

Why was the observation of the double-slitq 0)ue6ku mpwptt7;m-k;x bu- interference pattern more convincing evidence for the wave theory of light than the observation of d-pm-qt u7e)mxku;b6pt uk 0w;iffraction?

Compare a double-slit experiment for sound waves to that for light luh* /*yro5rq ss*bdwnb*qd lu pa7j0l x3:3+ waves. Discuss the similarities and differencesu3ls7rx: *sq*bo pwl *qd ba+yljn3*0hd5/ru .

Why doesn’t the light from the two headlights of a distant car produce an inteze 7 j2paicd3;rference patdcz 3pe7i;j 2atern?

Suppose white light falls on the two sli (6m uk+hrvjkrh5dl4+ts of Fig. 24–7, but one slit is covered byk5ru6+ldjhrkh v m +4( a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a f +gm9. fhjq+.e0aku;k+ wshlt lat piece of window glass, it is not broken down into colors as it is bq9akh ml 0e+juw;kh +ft. g.+sy a prism. Explain.

For both converging and diverging lenses, discuss how the focal length for red ( isrx,keu b+9,+aanb liab+uk9naexr bsi,,(+ght differs from that for violet light.

A ray of light is refracted through three different materials (Fig. 2wh.9nyj 9zs r+4–55). Rank the materials accor r 9yn+jhs.zw9ding to their index of refraction, least to greatest.

Hold one hand close to your eye and focus oaf l8j/,9uyjz raeh ;wr )t;una*w)( mn a distant light source through a narr8ljan(*j;ur9 efa,)rat) zm/; h wywu ow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slw-gq, r65iobh nz6 8df;pgxf pbv/ *n/it if the whole apparatus is immersed in (a) water, (dn qb g/bw5z v,gx- i;nop/ffp 6*rh68b) a vacuum, instead of in air.

For diffraction by a single slit, what is th/gyj5hl194f(g bqbyle effect of increasing (a) the slit width, and (b) the wavelen1y/(g5hb yf4b gjlql9gth?

What is the difference in the interference patterns formed (a) byxxbyfn 6ctw/lv 0ib8pe2qv2 1:f9i /n 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 sl0yyyd9vyv/xrwdtr 9u5 7+l b+its, (b) closely r/d9 v0b7l +v5yy+ rdywxt9uyspaced slits?

White light strikes (a) a diffraction grating, and (b) a prijnq(s t;.64m 2wctmkc(ssdq /49yp bs sm. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color ofmpdcw c q49s tq2s4ksnt6b(;.(/ myj s the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm,ymu; o+eufh:1 eky u(8 incident normally on a diffraction grating, for what orders (if anyfeoy mu h(e8uuy;k1: +) 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 filfdt o(g:c mi 7ul4me r.)(jg-bm like a soap bubble and not for a thick piece of glass tg ojld(bmu47)r: -fmci.ge(, say?

When a compact disk (CD) is held at an angle in white light, the refl, 7:s2t r7v ivvw1znsqected light is a full spn rvw1isqv7 :t,27svz ectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the center? l)ngtwf 86dpp( ,*wtaubb / w8

Some coated lenses appear greenish yellow when seenewaa: 0 (q9nj(7 :z3v7 my. ;nzcwql5fdbfmgt by reflected light. What wavelengths dcqdtjwavz7eb:mfn7.n(l0f g 9qw: ( a3 5;zymo you suppose the coating is designed to transmit completely?

A drop of oil on a pond appearhjbpqve j eldyear: 6 s er;799;w((t2s bright at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about threae7q:h(w9e2 b9d;yl(jtr 6p;evj se index of refraction of the oil?

What does polarizatioj,)zkz6fpz8c 7 s4gy kn tell us about the nature of light?

Explain the advantage of ,vl5x g(kasq1ol7 a; lpolarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarif / wf7d* rlmyyyj)im1z0 sd:-zing or not?

Two polarized sheets rotated at an angleqqk.;g -,ft2ud.x cd8f ec sf4 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 Earthzhjpknint4 b3 ;4 gp0: had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is +ds:4;;t/ta ihwvily+cj c0d, would sunlight still be white, or would it be some ot/h: 4aj;vw +;c0 ctitlis yd+dher color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-order xc19z,b0k3j9 x 3gs+kibqd nqlv /9ro fringe at an 8.8izr lk9 b + j,vx/01x3dgobq3ckn99sq$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at an p *y+w5mo , 79dn4wotyzds6c sangle 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 mm apart. Successivf bhxnn .1i1e3e fringes on a screen 5.00 m away are 6.5 cm apart near the center of1.1ibx3enf h n the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne lase b:68ltobem0rr:k5p lu5f x a k;*vji6r, with a wavelength 656 nm, falls on two very narro*lraru5bvbfpj0le m6:6 i ; 8 5t:kxokw slits 0.060 mm apart. 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 falls onx; qifsjx8k6li /47l p two slits and produces an interference pattern in which the fourth-order fringe is8xf6;k siji 7lxqlp/4 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,e e6:e) m.sxl h*9l+zuyns eb through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a9me:yb 6unlze*xees.,hl +s) screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue lighttzka dywq d1+x1*n5 (v of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at the same lt1n(wkx*1 5qdy zdv+a ocation?    nm

Water waves having parallel crests 2.5 cm apart pass through twsyjbv4+f a8056, u4ogp q40l zmctl.njf(l auo openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to th6cz 0byulq 8pa 0.fon,5m+sflajvg4utj(4l 4 e “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower slit in Fig. 24–9i7tiucp,f0 f7 so that the two wavesi079 fi ufpt,c enter the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the third-order maximum for light of wavelengt f;x:whncmj,:pmrh2kd-; +j7- j+nbqkc (a aeh 500 nm is located 12 mm from the central bright spot on a screen jxn p ck- h:k(db7hc: +r+f2wm-ea q ;jj;,man1.6 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 illdi-f3* 0v cct3rrx.4pot hp:fuminated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m fr4f3htc*rd 3 cx frvi-p0:pt .oom the slits.    mm

  Light of wavelength 480 g/da:, yx86b sd1cgsfnm 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 a hewi3-a+(mb ;a3/b4 b mblwzedouble-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being b 4ab +(/3hw -m;zeiabwm elb3a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red li qt- fdq pb 0ariq3,j*mls9.d3b t+2jcght (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (Se9j0i* q cqqm lfstabpr- d23,3 b.d+tje Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60. ) dw.8kwv rhb0yx0dm200$^{\circ}\,$ 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 wavelent,egl *x7 sgfm.clu54 gths, $\lambda_1\;=\;450\;nm$ 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 ot(m j v,:6adtby1*tmtp;gz :oat n +4aesr((pn a slit 0.0440 mm wide, what is the full angular width of the ce:t ,+ (amojm:64ynzbe tat1*t(ppad(trs ; vgntral diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a s95 h7 jl2earkllit 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 n ;hbglxc 4hska p2d6l9 8 /s4sz3scq5em falls 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. Wha ku 1,s83tzwutt is the width of the central maximum (in cm) in the dt8k,stuw z1u3iffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm fgr7 )co hn0dh jp;-,qosj5d-ualls on a slit. If the angle between the first bright fringes on either side of the central maximn7hjqogp,d;5sr d c 0 -u-joh)um is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m o0r 7mwushfii 6-b2x- behind a 0.0348-mm-wide slit illuminated by 58 os- 6h2b mfw0xir-i7u9-nm light?    cm

  When blue light of wavelength 440 nm falls on a sing.ph,n d no9d9ale slit, the first dark bands on either side of center a han9.d 9np,dore 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 cre 0a,2*yiisfon 07hk xwates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the sl0as w0x,fny2hoi7ki* it?    mm

  If a slit diffracts 650cva hw 1pa+mj,(,kl5y -nm light so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of t5ml1 k (,ha+wcv yp,ajhe diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengthsar7w .q *3mzocr c8gxl35k: x $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-order maximum when falling k1m kk4 g wk ,l-qz-zqmc+u9k1on a grating whose slits a cwz9kuk - qqgmkkl4+1m-k,1 zre $1.45 \times10^{-3 }\;cm$ 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 thirar1 r:ccsbnf( ce 1z,5d-order occurs at an 18 f s5c (1arr1zce,cb:n.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 falli-icvh,wv /3q lng on a diffraction grating is observed at a 1qvi/cv 3,h w-l5.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating has jkth13-go5 *dt+niuw-ap- aolo f;( p5brgm 9$ 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 oyt3amt+: ,cd:/gtl.r* ippmhn 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 thhq9.ac-wat; gds-g 8zat can be seen if a grating with 6000 lines per cm is illuminagdachg ws-8qt-z 9;. ated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on eithe7 rhj5-pc2dvwa,q ,ye r side of the central maximum when white ligpaw5,-drcj,veq7y2 h ht is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths frommbpcp0dt e--t0 )ofn3 410 nm to 750 nm falls on a grating with 3p --b0 t0n)emctf pdo$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light4wbj( c j d fvv61-1vuk.pdc:v 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 bspytt (au6 3f(p f1nfwe0uo; :y 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 1idcjmir j 2.+xcup/f 98b l+4t20 nm thick, what wavelength is most strongly reflected at the center of the outer surface when illumixclrit midub2p+ 49 +/f8cj. jnated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fri/,wj zc bhe a:u(ty:+pl(xs0onges in Example 24–8 if the glass plates are each 26.5 cm 0w(t(lx+,pzo: h:u/sebca jy long?    cm

  What is the smallest8ap zf2jqh 8lmm he0p bym68(: thickness 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 greenin/kf- (g, 4p*fpdiq evsh 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 3m. ql (5j 8r- eor;.k2xyvoc: jzr1onk1 dark Newton’s rings (not counting the dark spot at thjlzc 1rxoq .or:. vnk (o52mek8-; yjre center) are observed when 550-nm light falls 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 sept:r /bwpv a,f5arates 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).f ,w bt/p:r5va How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between -hw2w xl31yf-ler7 bltwo flat glass surfaces if the glass is to appear bright when 450-nm light is incident lhr 3lf 2xw-e1y-7wblnormally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolet/jc -3l.: bxccunyc rgcx9()sgn ) l-n 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 alcohls6pw6p.slu4 )qa-n xa 5 erdz-:ud l:ol $(n=1.36)$ 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 adzl-*a n50bsa pparatus (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquidzb asna5d0* l-?   

  What is the wavelength of the light entering an interferometer if 644 bsdo0 saj 9+57ju 1:dqvv d)rxuright fringes are counted when the movable mirr a17d9s0xqvjj r5:)sudodv+uor moves 0.225 mm?    nm

  A micrometer is connected to the mo lr(n zb vy zxwmsbm*al gqfm22 k0,:g+3f)5/cvable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes tg+w, mv r0/lzkf)2: b 3a2lzs5cqb m nxymf*(ghat 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 mirrpovz)h m *v,t5or $M_1$ 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 through a smal; o1* c7sfi1rf,dzltcl glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming 1 c*1drsoli7,z f;ftcthat the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientedt )v;wi 9oz zeh5ch*t-ph+s3ph 1mr7s at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle a v/wo j1bev)*x;o+ xefor an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if thkb2p/.k3lzof)- 5 lmw sidct ;e light is hitting the diamond 3pbo/d-2.)ms lti5k kz ;fclw$(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that n lr7ucz3d -mjkv(65 wthe light passing through them is a maximum. At what angle should z573 kn6wrj(c - ulmdvone of them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placedzjv9 :),n2rohiu)jml so as to reduce the intensit)o :2, ivjulnhr9jm )zy of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented k7*m1t2 dur o0nxf)rw4e3kug i3b;hr 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 oriente7 fbiwhknqey vp2f;90+ ht,- od 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 reflectijru*jug n;8 ;q.fp-jqons off the surface of water for light coming from beneath the surface? C nq upguj;.8fq*-j;jrompare 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 sheets, each of w29f i 6tc+adgwhose axis makes a 46awd+g ic9t 2f5$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength .-)ggq5f 5fql qe.stj$ 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 cu:wee 4ha6 p wb.fc.u+an interfere with the direct signal from the statcfe+: u4phua . .bew6wion.
(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 diffracwd ;ubek4-+deqn9e9tvy2v l.tion grating with u 9e-e v q4dbevtl 92;.y+dkwn$ 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 thrh yvqfth0jv:3k d hsc0(2,z.x ough two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order frinj2:sk3zh,(0x dcq.h0f h v yvtge 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 broadcasi w6dngfyx5 p*;p;. 6cii vor,ts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midp .*f pi6;n6v5;cxp,yoiwidgr oint 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 0.88i e5/i+v)w*fwy 0kxik; 0r-f fp8f xdi m wide, and blows a whistle of frequency 750 Hz. Ignoring fr+ k-dx8p*ff5)ii ;v/eiwf0iywxk0 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 slit of width 8 ancd7/a ,wsxD at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lin84lhfoa6aev,.;6ntsbooxtsr; 4m5 f es across them. When normally incident 460-nm light is reflected from the wingtalhavf6.6eof,bs54 ;nmo84 rt o; xs, the wing appears bright 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)a,8u mshfz4 egg(k* s to be no second-order spectrum for any visible wav4 g* hekmg)zu(,ass8felength?   $ lines/cm$

Show that the second- and third-order spectra of white livs8: y3lblfd19ud;hocgk 0f ;) buem;ght produced by a diffraction grating always overlap. What wavelengt1y s;fd f; uvd) bcgl3u08leo;h: k9mbhs overlap exactly?

  When yellow sodium lhc o*cvxww/e; d, h)r5ight, $\lambda\;=\;$ 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 gratinbw *kcy.+0*g.zvg5eli j)vf kg with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists ofcv j.+bf5i)kgv k*0ezwg*y l. 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 clear material if a minimum of 150 nm tzdo9.42ba zjn hickness of it, when laid on glass, is needed to reduce reflection to nearly zero whe4z nb9oz2 adj.n light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident normabis 27 k5epkqudl7uv0o:: / yglly on a thin sheet of plastic film 5vb7o7kq:i:ulduyesg2p 0 k/in air. The reflected light 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 neede-,p*o rtfxzsruk (y: /d 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 f0md4xg-oq d9e or the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm lieo-9q 0xmgdd 4ght is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thinyf0o+ *kkmyljoj 9)x7 film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24m7yxojk0)l jf+ k*yo9 –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/;( chjyeneq ;j f51vf a smooth lake is pol1; qv5;cfjje/y f(enharized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be pl6)eif u.s+lx bm jxb9/aced so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) of bu+j .lxfxm be i6s/)9
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission iv8 c6n(i/oeeb ab3 x6qy+cw,axes are at right angles. A third polarizer is placed between the first two so toan/cw 8c(qbv 36ii+xbye6,ehat 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 plau 95td-8 zttlcced 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 b2(tn dqwtiy04fq5 i 5fh/aq8.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emi hwn48t2/ qi dya 5bt0fq(fq5its 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:9ao.gr 9u3gsj um9qvjj8 cr 6 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 o3//jg7btidr$(n=1.34)$ 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 radiati1d tn,6w xz*whq48 fol3o tqrybh i34+ng 6.0-MHz radio waves in phase with each other. They are loc3xo4d+, h fyw*q r4wi6btt lo831 hqnzated 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 contaityy*w+nyh(y 7m80 .i qpv jsu6ning two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism (F u8vn.hyqp s7ti+ym j *60ywy(ig. 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 fl6 1hrm3wmap fqq1cjit,3r4 8+9cr iuy at 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