Does Huygens’ principle apply to sound waves? Toe(s4lutbk-w0uf yrgi0)(j ; z water waves? Explain.

What is the evidence that light is energxr -s.bsvhz 8.y?

Why is light sometimes described as rays and somumm/v6pmf: b1vx/ih6etimes as waves?

We can hear sounds around corners, but we can;.ui w4bpz;rn not see around corners; yet both sound and light are waves. E;z. n;rpbwu4ixplain the difference.

If Young’s double-slit experyx-/ sq (oce9 n-qg q8uiju:0diment were submerged in water, how would the fringe pattern be 8 dq-j-uox/90g qsu:yi qne(c changed?

Monochromatic red light is incident on a double slit, and the interferenvmu,xypz+1:dr p jwsoaj x )e.,4bn80ce pattern is viewed on a screen some distance away. Explain how the fringe pattern would change :x 8o b jv+)xmzw40ps,jae1d .pyn ,urif the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfejwl ua2g*y118.cy fyr q k1+dqre if their path lengtyc1f yy q 2 l1rgu1k*8a.dqjw+hs differ by how much?

Why was the observation of the double-slit interfer. esjlhhok.. :h.mlj9 m f5v4gence pattern more convincing evidence for the wave theory of light than the observsj m.g.. hh:f9jv 5ll 4hmoke.ation of diffraction?

Compare a double-slit experiment for sound waves to t*vp .siv);hsviwt7 2 r09pilthat for light waves. Discuss the similarities and difs2ri9 ts7ilwvpp) v0;.tv * hiferences.

Why doesn’t the light from the two headlights of a dist 8-rnt 5vhjd. tzzbd9,:t.uq eant car produce an interfer 8bdj.tqh9z-:tr,5t udv nez. ence pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is cho-: iao5:sfkmwz8 p :overed by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the scki fo-8o h5a ::s:zmwpreen.

When white light passes through a flat piece of window glass, it is (.hjvcw 1 o3ainot broken down into colors as it is h1cvoa. i(3wjby a prism. Explain.

For both converging and diverging lenses, diz2 :i4-rgavmgiy 3p q f.2+bqoscuss how the focal length for red light differs from that for violet ligh+rqvag-2oy 3mz24 fg:ibqi p .t.

A ray of light is refracted through three different matertkz s b/*e:s*/yebe4bials (Fig. 24–55). Rank the materials according to their index of refracs4b *besytez// *ek :btion, least to greatest.

Hold one hand close to your eye and focus on a distant light b f 4yf:aiv//ssource through a narrow slit beb:yivs/af 4f /tween 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 slit if the whole apparatus(skak 2 )z erz2.c*mi*)vrwhi is immersed in (a) water, (b) a vacuum, m.wc) * izr ihezv(k*s a22kr)instead of in air.

For diffraction by a single svs37 5gcu;iky lit, what is the effect of increasing (a) the slit width, and (b) u7 3sgyv5ik;cthe wavelength?

What is the difference in the interference patterns formed (a) by two sen.1-)h 2 khdyx-herk2.astb lits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating,h*q4*ybxl hsf ;4w cv*9mf6tq what is the advantage of (a) many slits, (b) closely spaced s*xhm* cyf4hwfqvq ls *4;t9b 6lits?

White light strikes (a) a diffraction grating, and (b) aribe/9 -jk*:a* p ouhlr7vz0 c prism. A rainbow appears on a wall just below the direction of the horizontkub *v0- c 9elorz rh7jia:p*/al incident 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 nor;om vd)ijoknd +nc-1) mally on a diffraction grating, for what orders (if any) would there be overlap in the observed oc; -jndkn)voi d +1m)spectrum? Does your answer depend on the slit spacing?

Why are interference fringeuccdi th9cy)f)n +80ns noticeable only for a thin film like a soap bubble and not for a thick c ))0+inn 8chfutcdy9piece of glass, say?

When a compact disk (CD) is held at an ang l/.oa 2*(,/us (bzi9nsm-xveuqvabmle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic lam9sxm /u, lbev-v2au zo(bi.sqn/(*ight was used?

Why are Newton’s rings (Fig. 24–31) 38ogd-uh3jzjwq( 5i e8hne s8closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What2nse(;pr1c-rlmm)n lr hh 7yrv9c* x+n3 s 4jn wavelengths do yo3mrpsrxh9cc jn)r12*l4l7s+meh-(; n v yr n nu suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thic0 z c,/h.a;c+q ctn6 jjqaygz3kness is much less than the wavelengths of visible light. What can you say cjct n0h ;3 zyaq,gjz .q/+ac6about the index of refraction of the oil?

What does polarization tell us about the na(li m asg)-(neture of light?

Explain the advantag+kq5xn 2ao3qxc 68xn de of polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunvaam6s m3:fb6 y3a5k eglasses is polarizing or not?

Two polarized sheets rotated at an anglewfa rv/0pqrmy23 7t :d3l*ico*-+,djlxczxu 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 E)ja7y u9i *f qnosdvq; ag.n.3arth had no atmosphere?

If the Earth’s atmosphere were 50 times denserwrz0 x8vnopi 7re0msm x(. 0r. than it is, would sunlight still be white, or would it be some x8e o0r siz7xm.p0.rwm(vrn0 other color?

  Monochromatic light falling on two slits 0.01foq t5k )o-yx+6 mm apart produces the fifth-order fringe ay5qxof+o-k)t t an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe opjw /+ s:amwq1f 610 nm light is observed at an 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 mm apart.v(cfsj1pfu+w4 h3td jy);5x 5dk1 afi Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determin1 ;vp( 35+j5cukd1wdf4fxati )jsh f ye the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nm, falls ons16p0cyakw3.c; bpd yci )p-dc*6 ywh two very narrow slits 1p;wp) c06 -a*wc 6ibd3hdycypcs.yk 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 on two slits and producesp4 jcmd ; :yv+jv lh1,+8npwopt./nhz an interference pattern in which the fourth-order fringe is 38 mm from the central frij+ y 4.oh,vczj:p vn1d8 mlwtp/n+;phnge on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, how 2co0-p p dzmo4far apart are the second-order fringes for these two wavelengths on a screen 1.0 m away2do o0m pc-4pz?    mm

  In a double-slit experiment,/ ;1m: mgwenwc it is found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a mw1/c mewgm:n;inimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings 5.0 cmq(tmlf 0k8mauz8z -/f apart in a board. At a point 2.0 m beyond the b(8 lmfz/au0tq-fkm z 8oard, at what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is zr;;c+esie44w jez6 o7u ger ,placed in front of the lower slit in Fig. 24–7 so that the two waves enter the slits rizecrs4 7zoj;e;e4ug we6,+ 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 lighmy6,; a jyu3pb(qwk 8owl:xj.t of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot w3j6:.m oxq pl w8wj uyk,b;y(aill the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. ff f,l*16bwon Find the distance betwb,f1n*f6w lo feen adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air gfaxz mr -9;z w80.7euiy8y4h2kim xrfalls 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 pl(1/iq 3g.mhm; uyepup j:w8sdastic (n=1.60) covers one slit of a double-slit apparatus illuminated byph8peg (m 3disq ;j wy.uu:/1m 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red ligsx5l9ms4mn4f 0 ag, h ilv5e-uht (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fig. 24–14.mun5l0v9xgeh m f44ss,l- 5ia)    %

  A light beam strikes a piece of glas/wdcfi5i+2u +w.k6vld f8kpm s 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 ligh od9i4 yna)qdt.fg lka1o7m11t 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 f*l7/6 diuurs -dimh3r ull angular width of the central u-73d 6*/h ilsrirdmu diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on/p0 h5q8;v 2pbxke)htgw0 k mz 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 5 /xq( i 9xr)ymu1tf.zd4iwy2p20 nm 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 illu,pwvnxd4 h0 .gminated by 450-nm light. What is the width of the central maximum (in cm) in d.h4 nwvx0p,g the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 n je(g942t octkm falls on a slit. If the angle between the first bright fringes on either side of the central 9gk4 to2c(tej maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.3u -lv9 zhb/gryq k) r/t0qs.h/0 m behind a 0.0348-mm-wide slit illuminahr/- s) vg/kt.l bzhyq/qur 90ted by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dark band *2knat8g nku-s on either side of center are sepakta8kg*u -nn 2rated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a sins;rg+o;b e(;bcs o)br gle slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away.;;(br ;)gs os crobeb+ How wide is the slit?    mm

  If a slit diffracts 65 -(kst7o3+ n/bncpzmz 0-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 the diffraction maximum o cmkn7p3/ +z-tb nzs(for light of wavelength 420 nm?    cm

For a given waveleng5e 5kq7:5sbtgwzu p l2th $\lambda$, 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 f.x9jj y9lyjx e kicgu 3)2)c5galling on a grating whose slc3g9 j5.i ejkyul2cyx9 x)j)gits 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 (nu7zd c/p,p agrating have if the third-order occurs at an 18.pn azud(,/7pc 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 6 / 9rs7he+bv op)vur-ced9xfof 589-nm light falling on a diffraction grating is observedhpbv67es9ur +d9r-)/ex ov cf at a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating has 1:ysgj8qc*vr eae:-9i(vghm $ 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 *xedd18t + l8 nxsw1,etv3hs-k-hmunon 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 spectralwg wd86genw e)1yd53 c order that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal i g1wywew3 gddc) 58en6ncidence.   

  Two (and only two) full spectral orders can be seen on ei i0vokj. dps5;v38qrk 9, 2fsq6vzr psther side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines 6,2j3kq9v;sfvkrdp z rs5q 8ivsp0 . oper cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm ,o3 +tp.tiv7dvm )m9sh3ewgato 750 nm falls on a grating with t+dvsom7vg .)9h33p ei,tmw a$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic li,bppv(/dlox+l -s1rs ght 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 measuredkfxv+ 3l/j (bbjc,2m4 js od.a 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(9iq (shyh; azs most strongly reflected at the center of the outer surface when illuyh 9sq;i((haz minated 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 qd .eszx1)piwz:gzm8kz; 3fli /i a(*if the glass plates are each 26.5 q pfzwgm zz/l.;xs ikeizdi:(138)*acm long?    cm

  What is the smallest n;qt,b v*0mlc 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 greenish ye s-yupodrbt93 zx-. k5llow ($\lambda\;=\;570\;mm$ 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 mk cjnje12u 31kt.(sodark 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 surface (Fig. 24–31). How much thicker is the center than3.1 (octm2nk esujk j1 the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically flat glass, as xennkp m+; f784mo0 p(h .*bgqodos6b in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with onf.oembh+kqp;oxm07 4s ngb(6n o*d 8p e at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass su )pkt+qli gj 9:h)y* u;nztq;drfaces if the glass is to appear bright when 450-nm light is incideng)*u:9)pn;;z l qqji kt+yh tdt normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a sto :x0l85odr.*ux x*3m m.t; qbr eqixbdlen diamond $(n=2.42)$ is submerged in oil of refractive index 1.43 and illuminated by unpolarized light. It is found that the reflected light is completely polarized at an angle of 59$^{\circ}\,$. Is it diamond? ----待选择----yesno 

  A thin film of alcohol ,fatn :x*ubau4gj l:4 $(n=1.36)$ 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 apparatusdp sb.b0nji9/h 4d r/(ke-hdv (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 th-hh. 9 djrie/vnd/4bs 0k(bpde liquid?   

  What is the wavelength of the light entering an interferometer if 644 brigh*es jku .e rb/hmv9w.e4ne/a ,t fringes are counted when the movable mivrn,4kubesejma/ewh.*.9/ e rror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interd (d2f/scnw+3pb0up/vlt js, ferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move,s t /ndjs,cu0( 3lvdpbfp+/w2 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 mirac2z)1r ;n yjv14aber2zcz4 : wz ksp1ror $M_1$ 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 interferometera5xhf0 ,fk 1pugu e+* aro4ot fc;1s5f (Fig. 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 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 f,xafaf1 5+kpsc;gof01he 54 *u utrointerferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 6 6cwxi) c7*ny trfo5e;5$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–gb +q tl.p s3(vbspbc+0lass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water4wdwe(/b,ep ll 2m;q f4p;ka k if the light is hitting the dia, f p ;ak24(d/pelb;mwklweq4mond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximum.f gs7r97) mafy+ie je6 At f+9 e)s e a7ir67jymgfwhat angle should one of them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plac9+qd.by, crxl2i7qumgo8h ,bb yv), qed so as to reduce the intensity of the incidentc,u ovgb+,.yqm2 8 lbiy d7,)qhxbr9q unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at 4ff;,*psa65zb 6 a zewv0$^{\circ}\,$ to each other and plane-polarized light is incident on them. If only 15% of the light gets through both of them, what was the initial polarization direction of the incident light?    $^{\circ}\,$

  Two polarizers are oriented a )wtsd1d5 /i i:bm+9oaru/ pzdt 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 anglru*(r92 hanh le be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, a lhr*2h9a nr(und 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 througx cg-rs,7 ll:gh five successive Polaroid sheets, each of whose axis, c-gs:lx7lr g makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength n e nbd/tx w,nqs*iq4vjqd*/;1, xq (s$ 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 airpfq/lrl7)saf+ke 0og*: mwlf6 *eab 4flanes can interfere with the direct signal from the statim rf0 wg*+ s6f)kaql4:/7b*le foaef lon.
(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 pasxa unt5a s9(q 0+th5n2a;,y yext c,tcses through a diffraction grating with x n9tane h c(tu0;+5cx, t5sayyta2,q$ 3.00\times10^{5 }\;lines/m.$ The wavelengths of the three lines are $ 6.56\times10^{-7 }\;m$ (hydrogen), $ 6.50\times10^{ -7}\;m$ (neon), and $6.97 \times10^{ -7}\;m$ (argon). Calculate the angles for the first-order diffraction lines of each of these sources. $\theta_{h}$    $^{\circ}\,$ $\theta_{n}$    $^{\circ}\,$ $\theta_{a}$    $^{\circ}\,$

  Light of wavelength 590 nm passes through two narrow slits 0.60 mm aparte3 i,8nxd7s cs. 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 lightnsx, se cd387i. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station oper. ls; oigv7i:.fhbis8i+k-g o ating at 102.1 MHz broadcasts from two identical antennae at the same elevation but separated+. i i:og v.-i7 8skilhg;fobs by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back from an outside doorway 0.88.4l e d.ws iqa:t:en5v m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not pos5 eas:wdqve4it:. l n.sible 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 wid ypr;teful+0gc-n2yfp* 45kyth D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a sr,nor/i gp1e7eries of parallel lines across them. When normally incident 4,i/oe1gn7 rpr60-nm light is reflected from the wing, 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 7yl1 9qvxq2mrgrating have if there is to be no second-order sp9lv17 m2rx qqyectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced ga fgus9g1dg f,9:k j:by a diffraction grating always overlap. What w asgfu:fkg19g:9g,jd avelengths overlap exactly?

  When yellow sodium lms 7a0euk;65jg txi)xce9t5n ight, $\lambda\;=\;$ 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 isb7j6ik 14qc.qz58zo at ekb5vqld t0 : viewed on a screen 2.5 m from the grating. The incident light beam consists of two wave0 k4dec6 7zaq:tkoizb.jvlq5bt5 q 18lengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 materi+w+ lrp nud+4gal if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zewdg4+ u+ nr+lpro when light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variatx1ccb(6uxdy:(w),66bkvy ; rohwd c ble wavelength is incident normally on a thin sheet of plastic film in air. The reflected light is a minimum ondbot6uv)crx y(;y( 1x,:khc6 wb6 dwcly for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an anti-refle,khjvkk s4h7j- h l42jsgi+6cctive 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-zerot.yzxwi* z*df 36qg)y) thickness for the air layer between two flat glass surfaces if.)qdg z3y**txi6 wyzf the glass is to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a think axwmu8np/ru-.-.:(s h aeat 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 zerwupn -uka raht /8..s(e -:axmo.
24-30
24-36

  At what angle above the horizon is the Sun when light reflecting off a smope/djyc m3;;3 qdjn:soth lake is polarized most stj:cn3j y;pe /;sdmdq3 rongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so ao72o yl d1a.pz5d /qdps to reduce the intensity of the incident unpolarized light by an additional p2p ol75dzdd/y1a q o.factor (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 9 ls3j q0n;postransmission axes are at right angles. A third polarizer is placedp;ns0 jl qso93 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 sucyin.x):(nzuox+lz / nmjr bkf6 ,w5k8cession 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 wre w+(9ijj zi9idth 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelewrei99z jj(i+ ngth 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 pl t*jux-t5 d1ne+d l+9ek,udc paced 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 2ct 2u.a9zae : :vlnhrou6h /q9rj8s2h7qgin $(n=1.34)$ 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 2c/ss 1q yknz1o5bxo: radiating 6.0-MHz radio waves in phase with each other. They are l o1/ zc5xbosk2: sq1ynocated 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 wavelengths, 420 nqflg3) ;rj/mc m and 650 nm, enters a silicate flint glass equilateral prism (Figmj;l f 3gr/c)q. 24–58).
(a) What is the angle between the two beams leaving the prism?    $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with    $^{\circ}\,$

  A Lucite planoconvex lens has one flat surface a 7vq (lni8zm2u;gk ato:ew03gnd 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