Does Huygens’ principle apply to sound waves? To watey+: 0th7 7un1tfgxnvz r waves? Explain.

What is the evidence that light is ener3(xo f p a)s d8nq2kh-p)t z)m tgz(+9flodc1ngy?

Why is light sometimes described as rays and sometimes as waveskdtmp89m5s;2sx u a 3x?

We can hear sounds ar 0-zsnp +hrm;vound corners, but we cannot see around corners; yet both sound and light are waves. Explain thpn0h;z +rm-sv e difference.

If Young’s double-slit experiment were submerged in water, how would *xlyj :dz7u+0pfjql9the fringe pattern be cha xlq9yjuf0jzl* d7p +:nged?

Monochromatic red light is in*-bfxxruujv) +n0 5r g.km zk6cident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe patt n+rf gk j*6zbv 0.kuurx-mx5)ern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively ivl5smbe73 z .,op+thdnterfere if their path lengths differ by how m btv7o,p5s.3le h+d zmuch?

Why was the observation of the double-slit interference pattern) ugp15b su,t xirez0* more convincing evidence for the wave the)xzue i,u5sb 10gtr p*ory of light than the observation of diffraction?

Compare a double-slit experiment for soml:5tgs2b3f m7 z9kr iund waves to that for light waves. Discuss the similarmm 2rgk tsf9:5b il37zities and differences.

Why doesn’t the light fromk.q 3,pu- dnph the two headlights of a distant car produce an interference u- hnpdpq3 ,k.pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is cov1xjcj6x d1t*hered by a red filter (700 nm) and the other by a blue filter* 1c16xdtxjhj (450 nm). Describe the pattern on the screen.

When white light passes 2 0 s*ta r9fvtcp1t x73niuoe6*ja cx:through a flat piece of window glass, it is not broken down into colors as it is by a prism. Expt*a*16:vnp ae0f37tcixxc s2 rju o9t lain.

For both converging and diverging lenses, discuss how the focal length for qxe 5b g.ktxz9dy-gw: qx9n /3red light differs from that for violet lighbqxwx gt:3 .99zqkny-5/ degxt.

A ray of light is refracted through three;ds-xfn ig bs(x lmpeq6su .nn7 8;74s different materials (Fig. 24–55). Rank the materials according to their index o n.;gs8f7 s-6ne7m qui;sxds 4(xpnblf refraction, least to greatest.

Hold one hand close to yo7* fp dabjdwu-u*1z 5nur eye and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the be zdn1** a5u-w fdp7ubjst pattern.) Describe the pattern that you see.

What happens to the diffract 5*ip xs45ekuyion pattern of a single slit if the whole apparatus is immersed in (a) water,x4* yse5i 5kup (b) a vacuum, instead of in air.

For diffraction by a sinxq9*hgvj:i xn1dej6 zygyp3tg* g59; gle slit, what is the effect of increasing (a) the slit width, and (b) the wave :i*;h69gj5 p dg vggxz3qeyx* 91tnjylength?

What is the difference in the interference patterns formed (a) ;z 3jsm+jm wvfx1*z4(hn, hrgby two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (a) many slits, (b) closehaw( 9uil7iol./jh5 bly spaced slits?h lal9w5i( b.ihuoj7/

White light strikes (a) a diffractifhvr6 3fa4/4lox ff (*qmw6a25i wazrz6zn c 2on grating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow in each case? Explfwi6zmh ffnoa4(l2 z/w r53rqax6z v*c42af6ain.

For light consisting of wave wyw w5,c7bhu)lengths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrumwh ub) 5wcy7w,? Does your answer depend on the slit spacing?

Why are interference fringes noticeablk zav 7,ao)st,e only for a thin film like a soap bubble and not for a thick piece of gla,v7akz so a)t,ss, say?

When a compact disk (CD) is h2l gkeqcf i+:1b q7.ldeld at an angle in white light, the reflected light is a full spectrum (Fibq2.kif qedcl71:l + gg. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fi2vm+7t g3c 2,* u* voguwi/eirzpr *lag. 24–31) closer together farther from the center?

Some coated lenses appear greeni h4jew.gs:(gn9 oir6 bsh yellow when seen by reflected light. What wavelengths do you suppose the coating is designed to transmit .:besg 6r nj 49whogi(completely?

A drop of oil on a pond appears bright at its edges, where its thickness is muz/ (umj8sy9 :ztmib5 p bgz6vw5k8+bdch +gzbz bvb 58 j5sp( m9tk 6/8:mwudiyzless than the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the nature of lightu4;,4mh:duz7 ofhrvsutqj/9 ?

Explain the advantage of polarized sunglassexr5toakiw+b 5w+ g u*65d1hg fs over normal tinted sunglasses.

How can you tell if a pairpb5 w :h8pnh3j of sunglasses is polarizing or not?

Two polarized sheets rotated at xa h/,jmnx(61jpfr - dan angle 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 Eare ,b 7:xs2w3z7 * 0ph(n3fjxk tgkirigth had no atmosphere?

If the Earth’s atmosphe ost3ihjkj03 4:tgaw5*v/kwp r3clt3re were 50 times denser than it is, would sunlight still be white, or would it be some othetk 3tjs ij:c5g3wko3pv3wh 40*a/rt lr color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-orde7e)nnm4 x9kbekw)fk 7r fringewf ken4b9)mxn 7)7k ke at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed a 0o-1wosd v;yjt 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 nyx )5v uxj1*gn. u:gzharrow slits 0.048 mm apart. Successive fringes on a screen 55zhy u: xj1 *vug.gn)x.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nmhk-cz2 . dw+ty, falls on two very narrow slits 0.060 mm apart. How far apart are the fringet w-d+y2kc .zhs in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two sli/ ybb/kbr7 ty*kaa1b2 ts and produces an interference pattern in whbk2 a/yt/rbk b7*b1 ayich 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 lighglurq /; ;fgz4t passes through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelequ4r g;l ;fg/zngths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is fous k.cz ;wom3la l 3;roc+jc74t xhg4j*nd that blue light of wavelength 460 nm gives a 3c;j.ros3 lw4tc k g4zj;+hla*7moc xsecond-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 apartwvir:, k*9gr(1ei0gt z*cf cd pass through two openings 5.0 cm apart in a board. At a point 2.0 m bey9c0 ti*zgf v*w,krr :1d(egicond 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 plac siym2guio u6v.:6:tunpdl; *(s svr ;ed in front of the lower slit in Fig. 24–7 sv;:d:u2i; vy mls 6 suu.snot 6rig(*po that the two waves 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-ord)j lxs1f6hdje jd:88b er 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. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the s:fheblj dsd jx1j68)8econd-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illumi0*gk yn70yu 3sba:hmh nated by 544 nm light. Find the distan y buy007nm:*h3gshk ace between adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 , 4iarr ,wcn:dnm 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=1.6 df),0rqpy+-r uuvy;mjbo meb3l+:lo ;e39xz0) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastij9 0rqy: f+v+duubp)oo3 z x mr,el-ye3m;b;lc?    nm

  By what percent, approximately, does thec00vwjx x f,g, jsezr;ub b*53 speed of red light (700 nm) exceed that of violexv 05jgb*jr sxfe ,zwu0;cb, 3t light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikesnzh* ,: qo9gc7i:fdsw 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 coylb o0:.s d4q3lip6*g/cwo eontaining 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 sln y0.xq l .ci.evknt*169 wbiqit 0.0440 mm wide, what is the full angular width of the central diffracti e .xyqw1.nin6v*0ti9lckb q.on peak?    $^{\circ}\,$

  Monochromatic light f yv54-w d8gvx4li 5gxgalls on a slit that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength 520 nm falj y 8kg7k3h.)7mzr)54 efitr4 twyisrls 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 b.*qj5ru b :zahy 450-nm light. What is the width of the central maximum (in cm) in tr:j. bq 5a*zhuhe diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angle betw)z, yi1nri)rq)1zo zc een the first bright fringes on either side of the central maximum is 3nq ,)zyc1zioz r1))ri 2$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a scyq) 8lprsn5q- reen 2.30 m behind a 0.0348-mm-wide slit ilys- 8)qnl pqr5luminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slf.o0lbxaw :g )9fi+ ybyqfw12it, the first dark bands on eithfw2. obf:bg0yq 1xw+fa 9l)yier side of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm favsg 3)-hfymk3bi 11j qlls on a single slit, it creates a central diffraction peak that is 9.20bv1shqjy3m k) -1fi 3g cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum5 ;2uwb iszuepo:3,hz,vja/ k2j2 plc is 4.0 cm wide on a screen 1.50 m away, what will b ph 3zub vc ,2;5za,wkojuis/2epl: j2e the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengtr5cg.)pj2i j xrgss cbsw+/57h $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm lig p; 1ml l3zp:cfuv-m* ol-ki gv5tn8d7ht produce a second-order maximum when falling on a gtmd:uf3ivc pp gnz k- 8moll57;1* -vlrating whose slits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a grating have if the third-order ocut0 .x( xj5r2w:qj idccurs at an 0qr5ju.xcwj (id2 x: t18.0$^{\circ}\,$ 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 dt)rs la-go- *whb(i-eiffraction grating is observed atr(tibow--*ge a) h- sl 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 ns uot m*p54o8has $ 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 normallh4.p yl)*e *dglr,mj py 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 spect -w ja:fm19qog:l jr2;ueckl4ral order that can be seen if a grating with 6000 lines per cm is illuminated j: lgjclm wq:fe41ra u-;o2k9with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen ol2 cxiwd2hebk qe:/ -1n either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm f1d-w2qbl x/h :ke e2icor the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 4v)kx-/cqwi( : +fhtrk 10 nm to 750 nm falls on a grating withiv-rt(/ x:qfkck w)+h $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which prylv9.4j)1spdt1g ,c3rizrwb oduces monochromatic light 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 ; fev3p5x gp)fp p4+7ytu4aozare 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 ref 8;vd-f jin0vflected at the center of the outer surface when illumvd0;in 8f f-vjinated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are th 93rmsi2ieu 1ee dark fringes in Example 24–8 if the glass plates are each 26.5 cm long?e1i2i 9u3rm es    cm

  What is the smallest thickness of a soip(f q5w,w2nf ap 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 yellow (mxk-2iue.r; ooa n)q- $\lambda\;=\;570\;mm$ is strongest) when white light reflects from it. What minimum thickness of coating $(n=1.25)$ do you think is used on such a glass $(n=1.52)$ lens, and why? $t_{min}$    nm

  A total of 31 bright and 31 dark Newton’s rings (not counting the dark spot atb0d k)+u bg2yr)i kbmu8yc2/kc8 q4jl the center) are observed when 550-n08y/ q)rkudgmkk8icycb+jb lu 4b )22m 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 separates one end of two piecer g7k x(rw.ru)s of optically flat glass, as in Fig. 24–3x g wurr(.kr7)3. When light of wavelength 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) should the air layer be between two flat glass surfaces ifdhg nn7 tfx;s-4 3)08xs: 3zugya6gmy zzu(ff the glass is to app4fzftzxnzm -(a6g gu3:fy8hd 73)g0us s;n y xear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, nl1pec1u3o ky jheh-0ornzi,(+ me++suspected 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 alcohol 0ve2 im :6jecu$(n=1.36)$ 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 apparab o(5eg+ssd0dchtx*x6/jp0p ,p( q l ltus (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 refractiv((jt+x5so0,pl/sc pql b 6p*g0 hxdede index of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 bcr bzgco1aby)f,jk .6 hy:l 6+right fringes are counted whzky:chr1.6j)a fbo6y+gl,bc en the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an inte*93eygev0jj:dl mzf9rferometer. When the micrometer is tightened down on a thin metal foil, the net num j9d*zlefy0e9 j:v3gmber of bright fringes that 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 mirror 1kp 81gaz6( fsm g8:oykygc 0w91uwwz$M_1$ 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–+)w8t0 uz onix sd;m j:e9m3zyu)r2 cb59) 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 t8eo yj0wdz3):)cbur 2nxiut sm+ mz 9;hat the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientedmu fud:hb(uzn(* ejx*:*ou i6 at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–g *::+rmllc dqnlass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a 0 exnsef88 pac6)bc 30dd c(mhdiamond submerged in water if the light is hitting the diamondc 3ec86 8mhxnb)fcdae (sd00p $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them(i98rn9djb fmjd4 - ,vne+ron is a maximum. At what angle should one of them be placed so that the intensity is subsequently reducb4 ,9n jn9o(fr nvdji8r-e+md ed by half?    $^{\circ}\,$

  At what angle should th ;3eouw-gj ed/h3k0+unwj yu v(f0tm: e axes of two Polaroids be placed so as to reduce the intensity of the incident unuvd:e(+;0 jk-g w wu/uhno330et fjympolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are or s7xf7hu/ 9bmciented 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 at 387( fke*bya4(kriv./1nb gv cu .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 ree8:fe w;rb bobw,mpq8y* i:( bflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewsterebbb r ,:w*:qmpo8 (ewi byf;8’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 passesit- .(as -5s:wv:uf.6ggz sue-swvq n through five successive Polaroid sheets, each of whose axis makes a 4 egs-uvvan s(w gs5-: :u.ft.zq6 -siw5$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength teg6 x3qtm,;0thzqke8uj *es 1hc;/g$ 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 mountak2e 0q+pr r8pnpa,p6 dins or airplanes can interfere wid8+20e,pkapnrqr p6 pth the direct signal from the station.
(a) What kind of interference will occur when 75-MHz television signals arrive at a receiver directly from a distant station, and are reflected from a nearby airplane 118 m directly above the receiver? Assume $\frac{1}{2}\;\lambda$ change in phase of the signal upon reflection.  ----待选择----constructivedestructive 
(b) What kind of interference will occur if the plane is 22 m closer to the receiver?  ----待选择----constructivedestructive 

  Red light from three separate source3ehje lj(dd/m+be2 c 5s passes through a diffraction grating with 2e/(cjl +dbm 5eed 3jh$ 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 passi vxq/- -aou7r o,et,mh2horad8*)o pes through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second,i,em* /v 7ad--at )xroqo8oh2u ro hp source of unknown wavelength 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 from wjwrh.k2 ymw .skyh1)c;a ) l86 cv.yvtwo 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, perpendiculyh)1m )l.hy v 8.kwc2wv;j6.krca s ywar 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 ou 3r1e,5ye2y w9y17c x*zmlf; xfhdhumtside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estim cye x5xlfmhh u37, yew9z* r1md1y2f;ate 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 D at a 30sgck42ft ;o-b nn 06kzpe1h*t$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across thf;t 6qujw /qppx 8h86i: jjmz3em. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an angle jji3 8p6 hz fqt /u;8m:pwjqx6of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per cebzoibeu1 dxx 1c*6z+.hq u/;hf p)-yd ntimeter must a grating have if there is to be no second-order spectrum fobq.;dzu1x*1hhf zy/i -6b cp +ou edx)r any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by a diffrn97mu6 -adqfp win .7hz nn3k9action grati .qi9nfn m 7963ah7np- dkzwnung always overlap. What wavelengths overlap exactly?

  When yellow sodium light, ,6,hlw muhmtp)u k5:+6 tcble $\lambda\;=\;$ 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 dif5y, 2kftbol8c fraction grating with and the pattern is viewed on a screen 2.5 m from the grating.5lf8,ty k2c bo 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 material if a m88p qlq r40fn,jczh.4h gh8ryh-8 t kgzx:)psinimum of 150 nm thickness of it, when laid on gl,8 nghxzs4qkpzgf)pc. -8:r 0lthy8h 4 h8jqrass, 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?

  Monochromatic light of variable wavelength i*tbvk06 *1n2kh2 s+:wdzr ,bpof nspus incident normally on a thin sheet of plastich k p+w,b2k1dsu06pnt f2zon*r:v*bs film 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 needed for an anti-reflectiv.m i;3zbrru *la g5,r(qq )p+oksi5cde 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 two flat glasjl (uxhg7f g7l3 c*v.ts surfaces if the glass is to app*vgxlj3u (c h.ltgf 77ear 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 thin film layered ovr y(u0 n1,hkon a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for(r, hnk0uo1v y 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 aex5hq cfxe 6i5(l -qa4(q;iuq smooth lake is ql4-euxcxqqi5q6a h;e5f (i( polarized most strongly?    $^{\circ}\,$

  At what angle should the axes owimyr+5 ds lj oleb3(mb5o1(/f two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the firsto ib+ /(5dsm3eb ymo5wl(jlr 1 Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whosv .:pkl3c3v;b2uj we;4y mmvp e transmission axes are at right angles. A third polarizer is placed between the first tvevm34;k c3;wpj :y2uv lmb. pwo 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 successioc65m w0+qogk.58f m gulnv wd8:g2dqgn 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 ip3sa 1517*k2n wl5boeeekiqw s pointed at 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 He-Ne laser). lpo 7e w siw1*5ban25qk1ee3k Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each p ok bqp-:/c nguem,vh+9hg* ,tlaced 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 :w w ya6n1pgke5c:ff-$(n=1.34)$ 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.p se7(-c81kwck)x amk They ac aw)x p-8mk(7ckk1es re located at points $S_1$ and $S_2$, separated by a distance $d\;=\;175m$, Fig. 24–61. What are the first three points on the y axis where there will be destructive interference? (Destructive interference in this case means that a radio receiver placed at that point would pick up no signal).    m    m    m

  A parallel beam of light containing two wavelengths, 420 nm ann q9o:zlw6 uqn-4s )atd 650 nm, enters a silicatn4qqzn:u9)ts-lw 6 oae flint glass equilateral prism (Fig. 24–58).
(a) What is the angle between the two beams leaving the prism?    $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with    $^{\circ}\,$

  A Lucite planoconvex lens has o qi,;gs m4wa9p u);olune 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