Does Huygens’ principle apply to sound waves? To waf-1ss lp hx7:zter waves? Explain.

What is the evidence that lighvdw h.ce;m( /mbdpx*8t is energy?

Why is light sometimes described as rays and rh1i e45bijk 9jw4kl3 sometimes as waves?

We can hear sounds around corners, but we cannot85pvu4iu-cbt5qd( rc see around corners; yet both sound and light arevu58prd5 cbt4uq c-(i waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, wy,s)ly o1wv4how would the fringe patt4wy o1wsly ,)vern be changed?

Monochromatic red light is incident o,k:) kr3 z0 iehqsd+apn 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 light source i0 zshq)ape:3 kkidr+,s replaced by a blue light source.

Two rays of light from the same source destructively interfere if their cq i/xbu+f,i,path lengths differ byqcibfxi/ u +,, how much?

Why was the observation of the double-slit interference pattern more confyfz snz*t8bfu (wq-p .8cmc or 8(,2zvincing evidence for the wave theory of light 2s.8zunmq *f f( r8zzwcof8pb-(,cty than the observation of diffraction?

Compare a double-slit experiment for sound waves to that f9inavq/hj;wq 7 mo1-ffcsb s5 7(+xpaor light waves. Discuss the similaritiesja h -qqmnvc75(;siff aw7obpxs+ /9 1 and differences.

Why doesn’t the light from thex jorp b(0qow8(xevh-/(d -jv two headlights of a distant car produce an interferebh-px(e ood (rj/ vjwqv-(x0 8nce pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit iso,b iygyc ;1o 6 zlsju.7t2i+p covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the sl;yo1gb 7p.utc 6z2iioyj ,+ screen.

When white light passes through a w wacrn /h+o+9flat piece of window glass, it is not broken down into colors as 9 rhno/+aww c+it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length forpgvh1 q9v*( bd; gz9as 8ek3os red light diffsk1v8q3 z eh govbdas* 99(g;pers from that for violet light.

A ray of light is ref bpu p6 8s-ho0lx.td7zracted through three different materials (Fig. 24–55). Rank the materials according to-dpl8pb 6uzx70oh. st their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a d4w8g y0nu 57c/lwh1s wceb9g fistant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe gn4gf/57c8hs c 1w bwy e0ul9wthe pattern that you see.

What happens to the diffraction patteh+/ls-68wramjr.kwbs 6 njpg ky4,h 8rn of a single slit if the whole apparatus is immersed in (a) watrk6,ws/kyrpsamw6l + 8bh8 ghjnj .-4er, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of i6 31hybx; dps xb+k(l1vr.qfjncreasing (a) the slit width, and (vq(1hp. xrblf6+j sxkd y; b13b) the wavelength?

What is the difference in )o3h9 s5wfce cci:(kbthe 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 adv -ba3r /m )2gs6emhglsantage of (a) many slits, (b) closely space)3gesmg2b-/a lm6 sr hd slits?

White light strikes (a) a diffraction grati t z1;o64imfxlcxh 4cs/ju +zj78aue,ng, and (b) a prism. A rainbow appears on a wall just beloczxt;e so il6a j fc7mz4 uu+j/,1xh48w the direction of the horizontal 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 nln-(xu0sdre c; a1 1iu-*odmfm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap -c mo*dui(rl0-n;1fux a e1ds in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringel mjoc v:82eu7dm79 txs noticeable only for a thin film like a soap bubble and not for a o9 lectmj dmvx72u8:7thick piece of glass, say?

When a compact disk (CD) is held at an angle in whit;u;q-cvb-vdx e light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromati u;- -vdxqcb;vc light was used?

Why are Newton’s rings (Fig. 24–31 wjiob b83he ktem0oc6.d *:6u) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by e ym amkme1 )l6uq) ilx4r+e+0l2 b9r-9sedqsreflected light. What wavelengths do you suppose the cl49x0 ye +qi r)m1eml-e sr6+beldmu)k2a9qs oating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its tu2yoz;fxk.7 9(z u dulhickness is much less than the wavelengths of visildxok;u7 u9u(z.z fy2 ble light. What can you say about the index of refraction of the oil?

What does polarization tell us pat) z-(9 ok(7eryvmzabout the nature of light?

Explain the advantage of polarized sung,anp:t-8p f*oe-e c anlasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizing o*y-tfje vu(doa7)7am r not?

Two polarized sheets rotated at an angle y/mz eel3;s mx1)cg ;jof 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 cov*t4wxxu6 53l xse efmj o74z;lor of the sky if the Earth had no atmosphere?

If the Earth’s atmosphere were 5 1im21gf 7en+c8b1hmo njq-lb0 times denser than it is, would sunlight still be whitemh-8jb1lmf1q2i gn b1en +c7 o, or would it be some other color?

  Monochromatic light falling +d+ vx absk0y/ c9qkd2on two slits 0.016 mm apart produces the fifth-order fringcq +a +9sbyk2vd/ dk0xe at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of yq)t:8jj0c/i 5:a aw yn1ztnx610 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 vgg65t k2y5u 0dcoi ptj6m6ci3ery narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the cenc63oj dy2 gtit5k5c m 0g66iputer 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, w wqpvn42n+ q gx2+i-bnii-z/q ith a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far+4zgvw2pxiin i-b-n/ 2qnq +q 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 produces a e-gl;+xp9jf wn interference pattern-9le;x jw g+fp in which the fourth-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 through two slits 0.58 mm apart, how fhm c-r8 xfwv ,g e1xqyz0x2;c+ar apart are the second-order fringes for these two wavelengths on a scrx8c0frw;ve 2x1zmqg+h ,cx- y een 1.0 m away?    mm

  In a double-slit experiment, itr sy v9)a-+6 /hautfiy 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 li9 uh yria+-fv)t6s/ yaght would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 c:r:xq q3ubac 1m apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relatuq q:xb: ca13rive to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placeh74r6z2bw8av6.nax wn fg)iud in front of the lower slit in Fig. 24–7 so that the two waves enteraafnbi82rhvw)46x7.g6uz n w 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 th: q6s ;pyet/ixnt a5d0ird-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen txps5e;06nd/atqi y : 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. fqo 5cr(t u:*eFind the distance betweect*5r :feqo(un adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two slidb 9qmrs zl9,9ts $6.00 \times10^{-2 }\;mm$ 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 doez:v: o/ 8j;gbqnn1w4sxomz( uble-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (min;b nn:( og4zvxe/8zojs:m 1 qwimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed th(tlsw29yv0rs hzszk0(epa:jc:c e08at of vio: cst a0zw 2ps(0v0zkee 8lc:yj(s rh9let light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes /hq2x0y)fku l a piece of glass at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light con3d7:c*y gizvu taining 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 angulbbxhh(qy -0n0 lomn 9)un2hg(ar width of the central diffra(n2n-qyb(g )ou9xbh0hhnlm 0ction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit th 1v/ydcn1k o*+lttj41 hpzcd 2g9xhg-at 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 msdau0 e l9g+n d5g;d+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 og4b* zh5z**kw i*usd wide is illuminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a sck5 **bhg4ws * zu*zdoireen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angzv;s /3 ;izapkle between the first bright fringes on either side oksaiz /;v 3;zpf 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 behind aa w 0(s2.xn-qake8 sdq 0.0348-mm-wide slit illumina 8s(a sqeq-kw 20x.ndated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the firsb loi5x 97g7h30xexrht dark bands on either sid xb lhe9x r73h7i0oxg5e of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single slit, it cykbo;j+d5c i;ub / w0hreates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is theb;+hbjdo0 i;c5 u ywk/ slit?    mm

  If a slit diffracts 650-nm light so theeyhs ,. 1mhz2at the diffraction maximum is 4.0 cm wide on a screen 1mz yh.s,h21ee.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt:ymjp npvb ;z:yut 5x/ n)kf96h $\lambda$, 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 fallin5c g6v (p tvv0ia2.oc3su it3mg on a g(vs332p ci05to vm6uigc v.atrating 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 doe qhoakdj8z7qwk 7t(z 7(5 kx;js a grating have if the third-order occurs at an 187(kq j z5 z(hoa;dtjwx7k8qk7 .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 fallinw;bq)(z7t t x o0xs3ujg on a diffraction grating is observed at a 1zt0(xxjbs w 3) t7o;uq5.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating uw8l:a6gbtj x 7h7j q l:n bgu cc7z80sa7r*w4has $ 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 normalz+t,yyn09f89o hd a ggrb8(8xpq)ne vly on a $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order that can be seen if a gratinv.s6c:p sry)x(g/( yu*h dhu3il5lo gg with 6000 lines per cm is illuminated with 633-nm lasu.cxor3udshlp g:/vlg()5 y * 6( iyhser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side 211oh0/ mc ye b4gwruwof the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm forrcy42h/beww 11u0o g m the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on(txz qci: ut/ flr8:d( a grating withxf zit8t/q:d(c:u r(l $8500\;lines/cm$ 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 known wavelengta96mlk(co2 vpnn vh4 3h $\lambda\;=\;6.328\times10^{-7 }\;m$ 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 meaip/b dum78 h n40bmae.sured 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 is most strongly reflek 2tzjq tg4.2octed at the center of the outer j.q2 kzto2tg 4surface 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 plateslwkavpy.. q- f9q.5py are each 26.5 f.9qa-wq pv ..lkpyy5 cm long?    cm

  What is the smallest ttqk hq501h- ;k x7jny p;h5nlxhickness 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 greenis gq:7jl594d nsw .vtvbh 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 3g yr1y) oamx(-jdfg )(1 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 surface (Fig. 24–31). How much )j 1)dygayxo-mg( (frthicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end .5qt2;8eic9hn jladjof two pieces of optically flat glass, as in Fig. 24–33. When light of wajthcq59j ned; a.i2l8velength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) shou unz6ijd d7jwf 6;f,t2tk /oqml;-q, zld the air layer be between two flat glass surfaces if the glass is to appear bright whe fz/wzqntmk, 6 o6u;djdf7;- ,tji2l qn 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspec:e f 6kn*c2q yjuh+kdue5t6.zo h z/n1ted of being 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 alcoho y pa7b tj0ll mjo ,1cez e*f07v4r4+o1xirv*kl $(n=1.36)$ 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 immerrp9wt6.w cu 91ui0 oxxsed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive ixw1r.99 6otucu 0pw xindex of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 eo/cp4kx,3eqq lhi:yt: 5x,2 htr 1 n8duh am9bright fringes are counted wheq 8,eeroyhudpnhq5,4: k9 tlix1t2 :c/ hmax3n the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirroro8wuv1*ulx,vs9 c6kihg; +l 4 dbdh,a of an interferometer. 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?8a,1dl;6vs w +,icghlhu v*kb4o9dxu The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror s*4 4yszpu;r.8 cg xdw$M_1$ 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 interferomete7nn2s5wp) 7ns*5sjtrivi )tor (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 7*) r)nspwn2j7 sstt io55nivthe gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientecr 0-ud r0:rep4-byc fd at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle forg9*hs/b rd9 da an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in watjlaw +t5sfh/:er if the light is hitting the diamond sat f5j+w/:h l$(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them ivh8ckdwu- dl dxp;8w 6ix5/8jx bt *:es a maximum. At what angle should one of them be placed so that the intensity is subsequentlyp8u8j c 8b5-dk;hxdxw6 /etwl*xidv: reduced by half?    $^{\circ}\,$

  At what angle should .vj6 q5t(. dwoszr;izq7bx * rthe axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized lightq;..7s6bxqdz r5rwiv o zj(t * to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are ori6vzev. oys- m6ented 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 oriented atd57tpq(nc):pkoa; p9r2 e 7hupk ns7c 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 ref3gzpzk ll: d/3pj1fy3ixjlm6;fvy 8 3lections off the surface of water for light coming from beneath the surface? Compare to the angle for y3/z1 pf8jxg jpi63k f dl;3l:zv3 lymtotal 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 P zv 7dwpp gp*7-8ehjau56pj p+olaroid sheets, each of whose axis madujvp p p w-68+e g77jphp5za*kes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength )f) 1 wlazxyh6$ 5.0\times10^{7 }\;m$ passes through two parallel slits and falls on a screen 4.0 m away. Adjacent bright bands of the interference pattern are 2.0 cm apart.
(a) Find the distance between the slits.    mm
(b) The same two slits are next illuminated by light of a different wavelength, and the fifth-order minimum for this light occurs at the same point on the screen as the fourth-order minimum for the previous light. What is the wavelength of the second source of light? $\lambda_2$    $ \times10^{-7 }\;m$

  Television and radio waves reflecting from mountains or airplanes can mxy6);3 gic;g9xusa ckrat 3r de/1z;interfere with the direct si3)9g;rti 1/xerdy amcxuzc; s63ga;kgnal 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 thl35,(eyqu w72unyvm a-v;(b r ynpkie ahl,+2 rough a diffraction grating with h 2,llnw bvmy n(-u va5k ;r3+iyp eu27(qeay,$ 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 ae8 u vvh)+och8part. The screen is 1.70 m away. A second source of unknown wavelengtv e8hh+v8 )uoch produces its second-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 frswa89onh)ar2r(o3q iom two identical antennae at the same elevation but separater n98)2h s3o aqaor(wid 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 m wide, an mfkvlt i ;a(1zt.c 36oujx,0id blows a whistle of frequency 750 Hz. I t30jx;ilc(6t vu1fk moz ia,.gnoring 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 sie f:(4fa kbi vu0d2 /fi2q,eozngle slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lij4cy ab3)5tjrme xv-/y7cm2vnes across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at c 7a-e vxt3)yrm 4/m bj2cv5jyan angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is to be + rfl5ugo p3k3no second-order spectrum for any visiblr3 +fg3uopl5ke wavelength?   $ lines/cm$

Show that the second- and third-order spectra of wd0o n,w 3xqj4)2 2wfhw8dp upfhite light produced by a diffraction grating a 2whqwjd )p8 x,f2dwn0u4fp3 olways overlap. What wavelengths overlap exactly?

  When yellow sodium lighvg+w ygm:1mmmazzr+b-,v :bfmz64y7 c+mq 8zt, $\lambda\;=\;$ 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 -g cn, uh(ek hk )5z9gjl,0ms zjn :dsfh3cp)0a diffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of two wavelengt(3, hn sgphlkkdnc j0 z,uj)ez cf9sh)5m-:0ghs, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 kn8de5to7ir dw:4 mb;material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce refleo7nd m8:5bi4ter w;k dction to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident normally ojkxptt*o.j d4q,hl.2n a thin sheet of plastic film in ak h4 xjt*ql2tpj,o .d.ir. 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 needed for an anti-rvb1d33y +fxi84jh gh xeflective 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 trr zb ad96-rsh (2cmz-wo flat glass surfaces if the glass is to appear dark when 640-nm light s-z-r2bh6d( mz 9rrcais incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light tf u 9:: ukoorjdjh*u(p ++jey/ransmitted through 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 aly+k*+euuu9 dorjp o h:(jf/:j l 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 +:wp7g*loh:w9 c-ztdl8 fsdq horizon is the Sun when light reflecting off a smooth lake is polarized most strzot q8:cfwd*h w7l-p+:gsld9 ongly?    $^{\circ}\,$

  At what angle should the axes of two P a0t 5*j/envkwolaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in*ev/n50kaj t w half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axes arch.+hcr8 yq6 w9)stx+ md;b :vy4zfexe at right angles. A third polarizer is v y+;8 mdzh6x q.twb scce+9r h:f)4yxplaced 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 vertical, at 3eg*/-2kot7eep rm. ;pr5cs qx+ rhmh 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 1.0 cm and is pointed atp ;r0mcuxi.(jm) j n7j the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a j. m)nu7x; r0( icpjmjHe-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers a*:,2vvl6*iwpia iosaq 7sh7 nre each placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap e8rf0r w/ 8jgzi64lom$(n=1.34)$ 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 other. Thq2kwj,)ntdc4wr2ne ,, b xc p,v e.if5ey rnfb,iwt2q)w, ckxep., nv 5j2e4,dcare 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 lightjf; t g; oz7bn*,j6rlb containing two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral ptoj bzbn ;,7g l6*rjf;rism (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 leg;1v; oljfew bba e .f4pl )z9y3v3qh4ns has one flat surface and one with $R\;=\;18.4\,cm$ It is used to view an object, located 66.0 cm away from the lens, which is a mixture of red and yellow. The index of refraction of the Lucite is 1.5106 for red light and 1.5226 for yellow light. What are the locations of the red and yellow images formed by the lens? [Hint: See Section 23–10.]
$d_{i-red}$    cm
$d_{i-yellow}$    cm