Does Huygens’ principle if:12w4 s5n tra)wytx apply to sound waves? To water waves? Explain.

What is the evidencel/e v 5r+seas bf/f.1d that light is energy?

Why is light sometimes described as rays andlo/glh u-cvo 0b0m2*utj x)5w sometimes as waves?

We can hear sounds around corners, but we cannot see around corsi 0 qg7o;yh*ppf856fu8 zsz:rfpab -ners; yet both sound and light are waves. Explain the diffeysaro*;g sp 8pqi-0z :5 hp78bfu f6zfrence.

If Young’s double-slxzk3(:jyc1 uzy2 n+ybit experiment were submerged in water, how would the fringe zyk (jn3b c+:2yy1xu zpattern be changed?

Monochromatic red light qak/bqo-nga kr) 91)8rgilhdk , +9u xis incident on a double slit, and the interference pattern is viewed ondgglkkb-+98r)ku hq 1qr i x aa,/)n9o a screen some distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source+e ojp(v n//ts destructively interfere if their path lengths differ by hnp vj/tseo/(+ ow much?

Why was the observation of the double-slit+9e f60sfjspw interference pattern more convincing evidence for thes sep f6wj0f9+ wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that forarzo,x 6 r (ry,fck8/zrlmg hw,hn/ ,a9 x.hi3 light waves. Discuss the similarities ayh rhco,.xz lk,/, /(rm9r h fx w6r,a83gnziand differences.

Why doesn’t the light from the two headlights of a distant c,6yhqc, eoy pr y8l*2xar produce an interference patternx p *eqlhyc,82,y y6or?

Suppose white light falls on the two slits of Fwjwn *zw(97yik) v q--dkw2m nig. 24–7, but one slit is covered by a red filvwqd( -wizy2-mnk)7j 9wk *n wter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glass, it is dw1+l3f0h8e gwc oakqzt.-: rq :yxw2 not broken down iex+gw3o-la:81w f hwk0q.z2 drc:tq ynto colors as it is by a prism. Explain.

For both converging and diverging lenses, dist(;1z2i0i n fvrtt g.hcuss how the focal length for red light differs from that 0nizvft.r g;h2 i1t(t for violet light.

A ray of light is refracted through three different materials (Fig. 24–5(uqb p*raw( gyyr3s1 35). Rank the materials according to thw1a r *p((uybq3 3gysreir index of refraction, least to greatest.

Hold one hand close to your eye 3 e9+bmtm-ipz and focus on a distant light source through a narrowebz m 3mt9i-p+ 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 sipj 1 owp58dqype*pfz 08vg;:nngle slit if the whole apparatus is immersed in (a) water, (b) a vacuum, inst:*pv0e 8yd8jgof;p1wnzqp5 pead of in air.

For diffraction by a single slit, what is the effect of inc2akr (x:503ld 2h3pvxzqke uoreasing (a) the slit width, and (b) the wavelengtpr:223 vk 0de 5 (q3ahkuzlxxoh?

What is the difference in the interference pattee4f9.psa(+cr 6 ) s mfb 1s67fh0yxw wmp8ibahrns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction graf-n28)b*)f ak.*j)nzbdwq x qn j t6tating, what is the advantage of (a) many slits, (b) closely spacfwq ))dj8nxaf zb)t6a- *kn.qj* 2btned slits?

White light strikes (a) a diffraction grating, and (b) a prism. A rainbow appx* i)n6q:qo20c lwff qears on a wall justoc6q2qf)i:nxl q*0f w below 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 nm and 700 nm, incider-no eo 17jakx9q /d1knt normally on a diffraction grating, for what order on -ja1 9dqk1o7xrek/s (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable r.)+f y + r77 rwsgkba33clgg38rmmq zonly for a thin film like a soap bubble an+k7mb 33rc7s r )+mawg8g3f gyzr q.rld not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the reflected/ik- +z5y;+vq*g ltahib mko;8:o:c dbi ov8r light is a full spectrum (Fig. 24–56). Explain. What would you expqhb k*+v okz5gril a;yo / ;vdti-8:b: 8+iocmect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fkexjgo+i(zy;2fl1 b( 8ji,zl arther from the center?

Some coated lenses appear greeg5a 3xp0r h7lpnish yellow when seen by reflected light. What wavelengths do you suppose the coating is designed to transmit completelalrgpp7 x 35h0y?

A drop of oil on a pond appearsypw4 .y 5rept,5k 5las bright at its edges, where its thickness is much less thley5a5, 4 pwkp5ystr. an the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the naturevxg t.zrzs56cs5v 2 5n of light?

Explain the advantage of polarized sunglasses over normal tinted sunglass9a yjicu 574us n/3apees.

How can you tell if a pair of sunglasses is polarizing ometo7cgm/ f)r dzo 1:k i:6p:pzy 56lbr not?

Two polarized sheets rotated at an angle of nxim:/2dax *9: citfj90$^{\circ}\,$ 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 no3 lmui(0upnu;k;n(z u atmosphere?

If the Earth’s atmosphere were 50 times denser thaq6rr nsx;ihf n9( 9h*yn it is, would sunlight still be white, or would it be some other c( fhx*hn 9r;9qsr6niyolor?

  Monochromatic light falling on two slits 0.016 mm aparh3+) veek- .j 9v.:msuib iwzrt produces the fifth-order fringihbu+)9 ek3mr:.wsi. ej z -vve at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringehj)jp0 .;knwqd cv33a of 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 na6he f:d.vl+ftkj:3xyrrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavk: f.:dth63 yj+e lfxvelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 653 ns0fg xtrciz ,0z/g56 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6 mci,tzrf3g0xs/z n05g away?    cm

  Light of wavelength 680 nm falls on two slits and-. d.2 slxzl((yadwhv produces an interference pattern in which the fourth-order fringe is 38 mm from the .vl. d2yx swld- a(hz(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 far apar(nxw9 z /b2ajut are the second-order fringes for these two wavelengths on a sc/2jza(xbw u9 nreen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nmu p g;fra gmqr /q/,684f-sweu gives a secondufwqp;e r gu,sg- 6f//qmr84a-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass througew bd1*7q5:u hual/cwh two openings 5.0 cm apart in a bb ww5d:cq*e lh17uua/ oard. At a point 2.0 m beyond the board, at what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is pla +kj(ql bfydy(j* y9e;ced in front of the lower slit in Fig. 24–7 so that the two waves enter the slits 1ye yq (d+jf9y *lbjk;(80$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, .jic *gn*jhh.the third-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Lighc j.i.jhg*nh* t 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 qo1jd u56fn7 htgu; 36rnqxo xxpr)*7by 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent brigh x63;xgqjr 7nunqf 7xot56up) ohr1 *dt fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air r bbdy+-c8- dbfalls 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) c(z tsfia)2cnk:k flk (v0bcp 7e0;t *dovers one slit of a double-slit apparatus illuminated by 640-nm light. The cent)id7;k pkv 0:s(* a(kfc0bnzet2flcter point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximatelyettyjs*ratd -.9 q 0)w, does the speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flir9 t) jwqt*s0t .ed-yant glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at kby6 (8drp ee2a 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 contain sn66*;edl/ ubtbmb: 1qy/hujzm/;k hing 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 thf67c twpw:iuz3:0z uy33 tzw qe full angular width of the central diffryf:zuziqztwtwup:76w 3c3 03action peak?    $^{\circ}\,$

  Monochromatic light falls on a slit tga : jh d4(0;qiehr0jmhat 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 fallsd(mu 5iits c7/ 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 illuminatedc. 3 /y1mvaae1.u zdpc. ei0pf by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattcd.ueae/3p.1pva. c0i z1fy mern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angle betwe3wkx 4elp:wqg(a:sn2en the first brq4 w(e:xgk2a slnp:3w ight fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraap yq b3frbnnp x6b/3c,7w :1xction peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm light? bc/p xb3rpn yn 7fb,q6: w1xa3   cm

  When blue light of wavelength 440 nm falls on a single slit93h m1tlu+p f2ufql5 k, the first dark bands on either sid1k l u5qm+9 pt3fufhl2e of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm fallsnssn 1 ,z9,6fyqprgh: on a single slit, it creates a central diffraction peak that is 9.20 cm wide on ahfp,g:y19nzqs 6s,r n screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximdfv jicl-s +:3um is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light+dijc :s l-3fv of wavelength 420 nm?    cm

For a given waveleng* 4qmms damh+1th $\lambda$, 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 whu 93eq0p5 zi(wfvi;k wen falling on a grating whose u0z5k3wq ;(wpeiv9if 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 rc fnj(a6m2yu4l) r+ql9inl1does a grating have if the third-order occurs at an + rjly64(i fmn9l2l)1 naq cur18.0$^{\circ}\,$ 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 difn8.g (2b6gi3jqnfhp8i6 q ddkfraction grating is observed at a p3q.6 niifbk6nj8 qh2d( gg8d15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating 3h . 15gchd+w4oe swcd0 *iqsuhas $ 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 normal )l.b8 nj-r ta1*9awxqw)ba vlly 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 thx us /t1t fd.4erh(pz8at can be seen if a grating with 6000 lines per cm is illumihtxsez/t.u1 4 d(8 frpnated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side r p7p,;fkr )ejvqk1)e of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating? )q;)7 , vrk rpf1pkeej   $ \times10^{ 3}\;lines/cm$

  White light containingdbz q19vbc+z , wavelengths from 410 nm to 750 nm falls on a grating withqz1vb9 ,z+ dcb $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic lightty 3 ig3vfmy)3 pru1/se:7emy 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 areih, .q .9e v0/pf kcq.mnh*yur measured 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 reflectm9u3wffh ;vp;ed at the center of the outer surfacm ;f39;hvufwpe 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 platidcj/lm:cg 4 )es are each 26.5 cm long? dmi g c)4lcj/:   cm

  What is the smallest thick 2w c+pgpwdibojzqr8- q/.a ;p1m,q6w ness 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 y/ mcax; k4k: ksvr2n-gz2/m ;scj+icgellow ($\lambda\;=\;570\;mm$ 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’scwi.f,kks/ 5p.g/o af-b 6x :/*df8ucnir qtk 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 than f/5u6x.gfpi* kbn/c odr at:wksf,8-k iq. c /the edges?    $\mu m$

  A fine metal foil separates oskrsey. 3( 6lr2(evq;m2aqul ne 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 eachqms;6v y(qr u.k2l3r (2esel a end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass b3,uv iuo.-**) is lnjmwqp,os 7g pa9surfaces if the glass **.s3,obn -7 jp,gv)qwalp imsou9 u iis to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stoih).;vvooe ccp k) 5/o(dzo ,eyw;vb/ len 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 2rh )t*s: 7t1rbkhjuml $(n=1.36)$ 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 (Fiv fn1)0nm )t4qhpj4ro2 oy ;ifg. 24–31) is immersed in a liquid, the diameter otm41fqoj n 2 )o;y4 pni0fh)rvf the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if gfm .o1hwpt:8k/ wz)y644 bright fringes are counted when the movable mirror moves 0.225.km1gw )fhz8 oy: p/wt mm?    nm

  A micrometer is connected to the mov awab kn mvrcxpq28;v 728w;)fable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, com2a28 krbw;fqan )vpcw7vmx8; pared 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 mir mn,zjzy1bszm52ock 5/d33vu ror $M_1$ 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 interr:w-khzb*if 2d .y/- 7xdsjmrferometer (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 wavelengmsr-bryw7*x2 i zh:kd.d/- fjth of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 6. a g1) o0ycwey8pwn,3zc wih65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for ans9 97ncrgs+flkeso *lz)4;ur1kkkf 2 2 :vhym air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submdz/8y,sh6i m92zlo wgerged in water if the light is hitting th9hm6lgzy/is8z2o dw, e diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passiq+zzd eil)/:rx5)j b we) f-gang through them is a maximum. At what angle should one of them be placed lrza):g)+5iw-xj)e ed fq z/bso that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plac+5pw(o+04rz povy qr ned so as to reduce the intensity of +roqwn(v 0o+r5 yppz4the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at lg0 5,-phnz m1rmg)v k40$^{\circ}\,$ 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 or c rpvj,w4xywv2whqjnp-gb-2c s1 -79iented at 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off the surface of 8h-gg; fk2uw( p qm-bdwater for light coming from beneath the surface? Compare to the angle for total internalgb-fp8 qmg;h(k-u d2 w 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 success x cbkqt+9fs(*ive Polaroid sheets, each of whose axisq+k*s(c b9 xtf makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 4va ud5+*ob5jpzl3rig ih 5f-$ 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 wav/5 af tns)po.hes reflecting from mountains or airplanes can interfere with the direct signal from tfnt)o /s5h a.phe 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 a diffraction gra f c2ed.g9q+vtting with gqd 2f+v.t 9ec$ 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 tzj4c4i-db1/pltyd o-rj 9w:pwo narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maximum than th1-d/zli bp4c9-py:tjwr 4 odj e 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two identical antennae ,qel(2b w-amb lp 94hzj bcy,u:u ./gjat the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is tbz 4pu gc/u.h,: lw, ebyl92ja(jbm-q aken 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 outs5t 7qa r-ln*vride doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections,lar7n*t-5q v r 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 o rvotf71/v7 ) pbtg arwl9r18sa 8:imaf 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 lines across them. Wn*;vabt, ti2 yhen normally incident 460-nm light is reflected from the wing, the wing appea tb; t2niavy*,rs 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 f *8h,k4k l/ukxq.h gutbv,s+if there is to be no second-order* ,kvh4+qg.b, ux hklf8skt/u spectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-o0 c+anb4pxwo5rder spectra of white light produced by a diffraction grating always overlap. Whaab4cn0xopw5 + t wavelengths overlap exactly?

  When yellow sodium light,nho.5ml sokft +,tj1* $\lambda\;=\;$ 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 diqfhqzrm(g3(k s5 kx -+ffraction grating with and the pattern is viewed on a sfm -k5zhkg( +rqsq (x3creen 2.5 m from the grating. The incident light beam consists of 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 oo0ihx jw00o/ i;w: fkmaterial if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an answer?:h0if/io0o xo;jw0 kw

  Monochromatic light of variable wavelength is incident normally on a thin s*d8 d)d2pwj5 i0qpl-up*ybgfso u +k0heet of plastic film in air. The reflected light is a minimum o0dqd upgk y8-*l5f*d+02os pjuwi pb)nly 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-rh-b j9 yrn:.l2raqhywc 6j+5yeflective 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 orh 7 5p0nrea6r5qcx7for the air layer between two flat glass surfaces if the glass is to appear dark when 64nr0xec775ph ro5r 6qa0-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted thl20u,z xh pdqyf308yvrough a thin film layered on a flat piece of glalfqu2z0 0dyy3,vhp x8 ss. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sunyk2 gg* r7fqp4 when light reflecting off a smooth lake qp4yk27gf r*g is polarized most strongly?    $^{\circ}\,$

  At what angle should the g0k9*ed 28,eex3)yq -x aazo fw8lojlaxes of two Polaroids be placed so as to reduce the intensity 3 eg ao *fo0jax8y2- l8ee9,kqzwlx)dof the 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 polarizer sheets whose transmiss1f+tw:x mrch.ion axes are at right angles. A third polarizer is placed between the first two so thar.t + h1mwc:fxt 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 plak+orp l tln8s z3q+q99ced 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 1.0 cm and is4e61suxd o ge g2jv-*s pointed at the Moon, whichgs6jge 1 s-x2ue*odv4 is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizerseqs gy,99wxn.cez ibsg ;;d8. are 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 dbrg 6,xex b/)3lzy(r$(n=1.34)$ 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 ot/o,5rwbo9;u) ,hh y; 5j/a qkxtuvzfrher. They are locatedotva,h9zy u /; 55okurh ,jfrwxbq /;) 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+0l6 nnjig cj* containing two wavelengths, 420 nm and 650 nm, enters a silicate n+l6c gjn0 ji*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 hag-gef(wmth-8jett 0ku 2 ,w: rs 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