Does Huygens’ principle apply to sound waves? To water waves? Expl(e8m ck90 +y8kr lffbk1j(js gain.

What is the evidence that light is enew-aho6du*+2 xvedbzn(w wx 40rgy?

Why is light sometimes described ayk 0o1sc0f 5trs rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yedz73) y xu ko*xypm45pt both sound and light are waves. Explain 5 7)dkoxyx p3pmzyu*4the difference.

If Young’s double-slit experiment were subm eu 1dfcd;;ieb, oj9m1rlx.m 8erged in water, how would the fringe pattern be chandx; eduf,9.jlbr;8mcmie1 o1 ged?

Monochromatic red light is incident on a double slit, and the interference rr05 *5fr0/aivtpl ovpattern is viewed on a screen somv5*ov0a0r it f5rp/ rle 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 destructivellv1-;x p+ uamspb *5gwtuk/co1xu4( sy interfere if their path lengths differ by how m-wsp 4oxl5u1a1psbgc/t( x vkum u+* ;uch?

Why was the observatiobp, nf3a nw b+ne* +vb3-e9xdgn of the double-slit interference pattern more convincing evidence for the wave theory of light b3n3b +dbp, e*9efvx+nng a-wthan the observation of diffraction?

Compare a double-slit experiment for sound wavewyx * ccnlw( d2)/n4whs to that for light waves. Discuss the similarities a cw w/hxn yl*)dcw(4n2nd differences.

Why doesn’t the light from the two headlightsze;dsq c qtm.o)-g7 e7 of a distant car produce an interferen; 7des zo7qm)tq cge.-ce pattern?

Suppose white light fzvp ()r;m i;1lbrtnbi*l z2d:alls on the two slits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern oml (*2;rvt;bi)bp rn:lzidz 1n the screen.

When white light passes through a flat piece of window glass, it ip2.cozw5n5v l4 cpv 0ns not broken down into colors as it is by a prism. Explainv. clzcwv4 5n02n opp5.

For both converging and divatl7/ n+0zifkd. /c7 ls*aimeerging lenses, discuss how the focal length for red light differs from t/ .t eima+nf/l7*di70sk aczlhat for violet light.

A ray of light is refracted t v7t1rp/( 1n3g ohzhtpfn9z l)hrough three different materials (Fig. 24–55). Rank the materials accozrt)nhnp3t97(p 1o/1 h fvlzgrding to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source through a4qp(irq ,56 d17 npcxi5amswc narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pa5cp rndc,ms xqiq 5a71iw( p64ttern that you see.

What happens to the diffraction pattern of a single slit if tat8:84qu1 n24 msn uggsql +hthe whole apparatus is immersed in (a) water, (b) u4q ql+8ts14ng2tmsh:n gu 8a a vacuum, instead of in air.

For diffraction by a(vofulh 0vx699 idd+r single slit, what is the effect of increasing (a) the slit width, and (b) the wavele r( x6fvd0dvho9lu9+ ingth?

What is the difference in the interference patterns formed (a) by two z )6 1h0frgvyxs9-mnpfz(cuhuz7;(v slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating1jj 4du.x qfq 9(m)oec, what is the advantage of (a) many slits, (b) closely spaced slujoe9j xd.mqcf)( 4 1qits?

White light strikes (a) a diffrwr6qp + .w3clxaction 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 thxqr3lp .c+ww 6e color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm / jv:trx1 g xxgij*s*1and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed specjir/x sjv**1:g1 t xxgtrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin filg gw09gyy9qv* yk.g7 izr1iu.m like a soap bubble and not for a thick*7qgvkg91iwr.iugyg y 9.zy 0 piece of glass, say?

When a compact disk (CD) is held 4o : uy7-vab/pkhg. slat an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see h7-.p savlk4 y:b o/ugif monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer togqxijt80:i3f k ep lj64ether farther from the center?

Some coated lenses appear greenish yel0dlk+h dwe3a t5n (,tf;*vrz blow when seen by reflected light. What wavelengths do you suppose the coating is designed to trakvz b dr,l 5dh;n3+(*tteaf0wnsmit completely?

A drop of oil on a pond appears k5h8 uw+j-h39l rbou3v r-absbright at its edges, where its thickness is much less than th+loh9b -uwh5 33 k-rbjuar8vse wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarizationzzqz 0, sc./uzlnk0 g5 tell us about the nature of light?

Explain the advantage of +)) a r 3+hqa)mbeabjipolarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses 4eu n;vmty5:u is polarizing or not?

Two polarized sheets rotated at an angle of 90 vxcymh)12 5d ucw.v*h$^{\circ}\,$ 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 hx)0w-7kfkx6x74wkbyrt * cz tad no atmosphere?

If the Earth’s atmosphere were 50 ti8u q s3- s,cpeve xu2vxdg1gje6 jhu1x.z. .r9mes denser than it is, would sunlight still be white, or would it be so6re1gx.exq,p 32 s 8vudjj u-.9ehu1.vsgzcx me other color?

  Monochromatic light falling on two slits 0.016 mm apar i:06 nncugtqlew0+ /ed or 1nkp-uu52t produces the fifth-order fringe at+q5nu: e10w r-u dno/2e 0lncgui6pkt an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 cd)m3-jt4(x0w dsjody 9i k(e8w v, jfnm 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. Suo z /t+wp/u(e ebaj39hbvsi*-ccessive fringes on a screen 5.00 m away are 6.5 cm apart near te3wbziepohtb/j-+/ *9(svu a he center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from auh1 .o0hkg(*,rlpacanmm h ,. He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How farh,anrok(p.,hh 01cmga ul* .m 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 an interferbyr1u9i ;cd)u /j4c(,ygvs ,zlaiwe9ence pattern 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?i) ug4( brsylj;9/i9 d,vyea ,wcu1cz    mm

  If 720-nm and 660-nm ligh. g8qe 3),v av.sysy txp:x+cit passes through two slits 0.58 mm apart, how far apart are the second-order fringexp .3c ,+tv y:8vgiy saqex).ss for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is o/ *kku 25dkhxx6uq s/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 minimum at the same locat x *k//xho2u ku5kdsq6ion?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings (l iv 7;61qoytyq pv:q5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “straight-through” direction would there be littl1qpoiltq yy;q( 6v :v7e or no wave action?

Suppose a thin piece of glass is pe2wo:) l6i4p ;z ir.)htpxkhplaced in front of the lower slit in Fig. 24–7 so that the two waves enter thi 24kt )p h:. 6ex;poplwi)zrhe slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the third-order maximum for light of wa.c* h3wt:vzxgvelength 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 frwxz.t* :3g cvhom 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. -l*gq,(e vilda70u ck Find the distance between adjacent bright fringes ok d* 0ue v7,l-(cglqian a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls or,o r7 ckj u;eznp2;s/n 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)yi2h djb -ub)f fz.c,2 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 (u2. zh)yif2 -d,fc bbjminimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exced -np+ dojr5.do9ac2b ed that of violet light (400 nm) in si+2opad 9r5jdoc db.-nlicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a pi y) 2v)cmw- pooly+nh.o/gcnq 19a8ckece 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 cont0lxtqp+vb,dxsf(-s3 z 7i+f vaining 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 io,) wuntx,8et1px+itx0ksp440 ww1 h ecrnv;s the full angular width of the centr81s,ehn)vp, kxw w4; nt tpotu+104 exicwr0xal diffraction peak?    $^{\circ}\,$

  Monochromatic light falls onfwz (gk-1wfy0 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 falls on ag4*jz+og h3, o uvyy i):;kmvr slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide is illuminated by 450-nm light. What is the widtmdj /wkv/nd;74ex tl4 h of the central maximum (in cm) in the diffraction pattern on a screen 5. l7jdem/d/;4nktwx 4v0 m away?    cm

  Monochromatic light of wavelength 653 nm b6rp-k1x eld:falls on a slit. If the angle between the first bright fringes on :1k6 bpx-dr leeither side of 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 b1 jtlhr6yk5 0n8gu lasvw:h76 ehind a 0.0348-mm-wide slit illuminated by 589-nmy tnhwa67ulg6l0j :8kv hrs1 5 light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dark ba7qsppeo./, p7p mm pq8nds on either side of center are separated by me 8.mpqqo p7p, p7s/p55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single slit, it creates a cen-6 8h hwx:mhoatral diffraction peak that is 9.20 cm wide on a screen86o h :-xwmahh that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum aqqnbtb(v.h63e eh:f6,( n4fncmk 1o is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for fm.boc , nte(f:(nvb46hqhaqne 136k light of wavelength 420 nm?    cm

For a given wavelength cn oql,r9/;sm3y4x gu $\lambda$, 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 :2 kuq1 7plmx89atag)p:pxbhwhen falling on a grating whose s tpx:h:u98xg)2pk b1 pma q7lalits 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 n a.+iaw84f mygrating have if the third-order occurs at an4a yn.a+wif8m 18.0$^{\circ}\,$ 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 lct x(* sqj 8pd6lg:m;om5h d:yight falling on a diffraction grating is observed at a 6(j*hmqo:gpyd 5;8 mls :xtcd15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating xs)3bdl,b mfkenv6q l)i3a2-has $ 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 on a ;n)a/1*qgm0lo.0 t mi*mz.kzx , eia g 0pasby$9700-line/cm$ 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 spectr3ob7j;td n1t xzt/)rfal order that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assumen;ttor/j1z)xd 3t7 bf normal incidence.   

  Two (and only two) full spectral u:1*duzy*d6zx on g/c- lee3fveaj45orders can be seen on either side of the central maximum when e l/ uvcd-g*dn15ef36y zo:ux ja z*e4white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 9)xzwskozye*0 yy n4: 750 nm falls on a grating withy:ykw ezsn 0* z)x94oy $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochro a/xp e(mfkdd(bp.,p xplf.42n9dpv 1 5-kir ematic 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 are me/ ohe15e wvx/zasured 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 wavelen5(gg rsrtg4a 20h7zfbc/ 2 n 4yce1fnigth is most strongly reflected at the center of the outer surface when illuminated normally by white light? Assume tha047n f/ezft4rc5h gr(ncgbiy1gas2 2 t $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 246yjk6k+ohb/)esq q, 44 1 t/ xhmcsfbx–8 if the glass plates are each 26.5 cm long?k4/bsj/6 k4s x) thfchym1bqo6+,q ex    cm

  What is the smallest thickneqnv jz0v-*lv 6hx2bd (ss 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 greeniwn6agq oyj urkx -o24x;h 42g0sh 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 31 dark Newton’s rings (not couacf+vv yl4(fafxi56bk+ 0(sc v 7nyf.nting 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 cen+(+ffa4 f.cxvsnf(v5bcy7ai ky0 6 lvter than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically flat glass, ain+8u 30jkb al+ 8gbu .9uwjrks in Fig. 24–33. When83+8.jru bklu 9bjn0 iukwa+g 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 glauz 0cftl8h9g ,ss surfaces if the glass is to appear bright when 450-nm light is incident normally? 8gc0u, lz9fth   nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a 6+v+nttvg yo0q1g3m, dkc; qh 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 alcohwk kkit(f0nu0 c.k0* dol $(n=1.36)$ 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 zczr-bt;*l2wx qof6( (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2. fr;( zwb2czl6oxq-t*48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an in8gnqj .km6i (i v5+kdu2x rzg-terferometer if 644 bright fringes are counted w+n-u d2 gr(z xkgqki .m6j5iv8hen the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. Whenc1 etaoq4 eczcb 7)*,y 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? T1 oetc4*caq, zcey7)bhe wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror w-jai ,9f+mg/ kw/ dqqg//yba$M_1$ 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 interfero:kqawg; kn. p,5 g5+ykwsu -acmeter (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 totkqnc-k.awpykgsw,a+u ; 55: gal 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 interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented lb s09 pw)g:)w1irj; 3lwmrih at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anglektz ma7g0w,-z for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diam:b6.+ ipdi z,*4cpiuga v /0qbqm/wqaond submerged in water if the light is hittinb4cmi pdq biga+6:iavq*/q0wp. zu,/g the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through oqe49f 8x,xninys5bn8r 3ui. them is a maximum. At what angle should one of them be placed so that the intensityxiren5y n nq38ox4bsiu,9 f.8 is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroid 1nxk7 m5y.amgozfu5lx8 .-qms be placed so as to reduce the intensity of the incident unpolarized1knzf.xxm- a m5y.l58gu 7mqo light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented ahm: 2b28 lqnmbt 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 38a x1way95+ edf1 /zj2smz) ,gx/x6rn:qv ixzg.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 reflmfh5.lscjm( rh8 .r,c( ) bqiqections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle mrh(q.bcs ij h5f.mc,lr8 )(qfrom 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 thron) pm8t: 1tgpough five successive Polaroid sheets, each of whose axis makes a 4 ttog m:p)8pn15$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength luy.l ;)kx8 gj$ 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 airlq/*d)v 7kzp zplanes can interfere withk /lzv )*qpdz7 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 sources passes through a diffraction grating wit-x u( r bitg1:s0giw9/kmwp/gh iis:gpu 0bt/w/9rm1kwxg-(g $ 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 passexq.+nn /zkc t,s through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second soun .n+t xkcq,/zrce 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 two identica :br 43iwjj3jbl antennae at the same elevation but separj:ijwb 34r3 jbated 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 agtbjy, il: p7ap4-7p- ffiod:n outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimalp7 oi -d:p:pab4g jff-y 7i,tte 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 wek. .1gkm 4hm;j 0iwbmidth 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. Wh)8zs/,h qjw 7dzr/h nven normally iwh/,zz7ds)nvr / 8jq hncident 460-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 centim gfpfv*95w2jb/m d.ujeter must a grating have if there is to be no second-order spectrum for any visible waveu*w5f b g2jd p./j9fmvlength?   $ lines/cm$

Show that the second- and third-orde s ,hxiiq*tg 7ast;8v-r spectra of white light produced by a diffraction grating always ,s;ha*gsqt- 7i tx i8voverlap. What wavelengths overlap exactly?

  When yellow sodium lightsfdp1 q+iz:p /, $\lambda\;=\;$ 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 is viewedcv9n trrd3i9 ls-nv43 on a screen 2.5 m from the grating. The incident lig9-t9ir3rnldnc v v s34ht 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 mate6 6v7;k ty ge43tclizerial if a minimum of 150 nm thickness of it, when laid on glass6z 64;l3ci ygevk7 tet, 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 is incident normally on a thin scu r * pw8cm7 flt. mlfe;560hk4k/ggcheet of plastic film in air. The reflected light is a minimum onlyck0fmh6 lcf. ;lg8egt *c5 p/4m rwu7k 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-reflectpf,p cx 13pp;pi/)w)z milt( dive 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) thim87/;e(sgw.62 qofe p kilofxckness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm light is incident wg2k .mqs lxf8e6if7(;epoo/ normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layered on 8h 4hiwn2d+ w*ba* ddla flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 2 8*ahd4+blwdwd2i hn*4–36, and describe the conditions required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light r3*z4d5lv uf jfk2 k 4-zz1dcvieflecting off a smooth lake is pozf-41vd k3z 2 clij* 45zuvkfdlarized most strongly?    $^{\circ}\,$

  At what angle should t 2 k(ou2dhiqniaqxce 1e(-28ahe axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light qqie co 1-8h(e(ai2dxu2k2na 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 polarize 0w 6 c62u+hrk4zyvjdoy j8(zer sheets whose transmission axes are at right angles. A (+rocjh yv u620y6zekwj8dz4 third polarizer is placed 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 8d.(.qu okf,r 1wff r 2/yywcpin 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 througtashf -:wmj20 n.oi 4hh a slit of width 1.0 cm and is pointed at the Moon, which is approximately 380,h2.-:tnswa 4 fjmohi 0000 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 polarizers arehjspcv 7f.r *sb9.3vx 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 vi)szw6t +;lfsv/q o2$(n=1.34)$ 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 pha87qo0hosc t:w se with each other. They are located at points 0h 8ctq7 owo:s$S_1$ 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 j,2-ybp sf,p4gdq3q:nx kdn a:s/m;qcontaining two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism ( 2b,nyqkq;gps : dfpaq/ds 4mn-,j x3: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 du1n0i x )pu6 eflqmg/1 sj/c)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