Does Huygens’ principle apply to sound waves? To yyxbmvy4,dg :6hf owq e; x0,0water waves? Explain.

What is the evidence that 45tqaq,uq:h a:kcvz . light is energy?

Why is light sometimes described as rays andtxf +dn/1(y*u 2z/a* v cvdw4xk;afzb sometimes as waves?

We can hear sounds around corners, but we c:dvjvo0vi9romj ::3kannot see around corners; yet both sound and light are wriv oj03: :o 9jkvvm:daves. Explain the difference.

If Young’s double-slwryu i)qcc ul1v/ hz tt145)p-it experiment were submerged in water, how would the fringe pattern be change1vuywqu-p4li )z1r/5)htcc td?

Monochromatic red light is incident on a double slit, and the interfeb/l y*lqk9*p( daa)nfrence pattern is viewed on a screen some distance away. Explain how the fringe pattern would change i aqb(l)9k*fyn*p/ladf the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if their v nn hs/ cgpsupc.m1umg0.9;5 path lengths g.h.0p /v 5 pmcsu;unmc1g9ns differ by how much?

Why was the observation of the double-slit interference pattern more convincq n7 r4bp, hf6lu9+/2olpc6 ( scnxdnxing 4rq( fp sn ndnc6pol/l 9 x,+7hu6cxb2evidence for the wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for light .(v xet* u)8lwufh(w llg4ar.waves. Discuss the similarities av x)8.4 (hl.u geur ltw*fl(awnd differences.

Why doesn’t the light from the two headlights of a distant car produce av2c *w((onoul o1mfs,n interfere ,s1umflon((wo vc2o*nce pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit ik:3qjxr6v ik3s covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screenjqi3 : 36kxrkv.

When white light passes through a flat piece of wino3qb:+c ducog8 k);q ndow glass, it is not broken down into colors as it is by a prism. Exp)8qdbc qk+3; on: gucolain.

For both converging and diverging lenses, discutysgkc1jt*z / d. aui01.c5e zss how the focal length for red light differs fz*iktz 1e .sa/ y dtuc.cj1g05rom that for violet light.

A ray of light is refracted through threqb6 g l9(g/phze different materials (Fig. 24–55). Rank the materials according to their index of refraction, least (hbg6 lgq/pz9to greatest.

Hold one hand close to your eye and focus on a distant lw(f(trl;g z,o0c :wemight source through a narrow slit between two fingers. (Adjust your fingerlgz: m( c;ww0rtoe( ,fs to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a sqs+x2rl0xax tti4- a + 5vggf p)qe:.gingle slit if the whole apparatus is immg +.-sat)l 2pgqa4ftie+x q x5g:r vx0ersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (a) t/a kg++8i0itvb)k 7u (ju ottphe slit width, and (bup +giot0 7 k k8uajb/+tti)(v) the wavelength?

What is the difference in the interference patterns formed (a) by t h/dem w+fq+u7ovbt 7.wo 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 sfekj1 j7fa+cq j9+2h 0u,u ucxlits, (b) closely u ,u7jujecjf+1q 9hck20 x+faspaced slits?

White light strikes (a) a diffractie.w,sjj z,r kvv0 aw0x xjlf09yr0/v31d v+hson grating, and (b) a prism. A rainbow appears on a 0slw.9 aj0s,ed +z3x,xj jyfv vv rkhv0w/ r01wall 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? Explain.

For light consistingkrp7ydk/) 6et of wavelengths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Doespr)/e6ktdy7k your answer depend on the slit spacing?

Why are interference fringes noticeable only for a 7:0sx so y5u.kc msln6thin film like a soap bubble .7 sslx u5y m:nk06oscand not for a thick piece of glass, say?

When a compact disk (CD) imwoti ;ip;z xx3-+ kg.s held at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monoch;pi+tkg; oixz 3-x.wmromatic light was used?

Why are Newton’s rings2marvqpoj9ep ,* mu-+ (Fig. 24–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected lig/f 1 epiar pebg np;(k+6d+g2iht. What wavelengths do you suppose the coating is designed to transmit6f2n1(bkag/ ;+pep+dii r gep completely?

A drop of oil on a pond appears bright at its edges, where its thickness is muc93m skses72jqr k.u1e6 -k dbvh less than the wavelengths of visible light. What can you say about the index of refraction of the e2 s3b 6kekv.u q1s-sm7r jd9koil?

What does polarization tell us about the nature of light-,h/hp(fvjou ?

Explain the advantage of polarized sunglassesvl00rcnp f48 3e +nszi over normal tinted sunglasses.

How can you tell if a pair of - h cqa(4q:jzosunglasses is polarizing or not?

Two polarized sheets rotated at an anglewv-q j 4f )hf1m8ehscen/e6-j 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 Earth had no atmdge ,53-lzlsc osphere?

If the Earth’s atmosphere were 50 times denser than it is, would s(mgl u6yro 1e1b:lf61ug wws/ unlight still be white, or would it be1 mu1/flwsylg rewu 6o:(bg1 6 some other color?

  Monochromatic light falling 9nn0w.ffu yo9on two slits 0.016 mm apart produces the fifth-order fring9uon09 .fywfn e 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 at j0q,mtdx*oi l/qx*8f w2pk0u 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 0.0a -9lla,q:oqj2 t,-l qcpb)cu48 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of u q,q2,pc9lb)ct- laajql :o- the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of lc2hfg+dvof( + ye )*nkight from a He-Ne laser, with a wavelength 656 nm, falls on two vef +hy n*g(c2fo ek)+dvry narrow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and proky9q9 2sm*n)smg4 fe qduces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is thn4yk9qqs*gms) m f9e2e separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, how far an-/x- pyfr 1hmpart are the second-order fringes for these two wavelenn- mhxrf- /py1gths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nmforq f s 9k8p+()nnbua0 h79th gives a second-order maximum at a certain location on the screen. What wavelength of visible light woul(f 9phsr 07nfa9)hb n+kutq8od have a minimum at the same location?    nm

Water waves having parallsi ;i i:yv5r1jel crests 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “straight-through” direction would s;r1 viji5y: ithere be little or no wave action?

Suppose a thin piece of glass is placed in fron/i+dvo5 ptu -mmd/9 hkt of the lower slit in Fig. 24–7 so that/o5 mpdkt/m h v-+i9ud 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 experime8i.vmjo,-gg0w3:*dk l kvzkynt, 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. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum .3mldizvokyv:8w gg-j0k, k* of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. Find the +r8k+-oaiqb .k3jzzx distance between adjacent bright f83x+ .jzazrkiokqb+- ringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls onw .v.kfycgod6,q93 vc 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) covers one slit c) atv(b g806 rw7khgsof a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is k stga )wr8bc7v0 6hg(the (minimum) thickness of the plastic?    nm

  By what percent, appr 7sxifd8//m, uof:2ml-q eb sioximately, does the speed of red light (700 nm) exceed that of violet light (400 nm) in silicasiou x l 8dffe7: ms/qi/2bm,-te flint glass? (See Fig. 24–14.)    %

  A light beam strikes kz8kh;1 q bep;46qmvl 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 containing twoq . hu1hk3:gcs 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 pt x3cc,g-gpj fb l/43wide, what is the full angular width of the c jtf3g-x l,4ppg /c3bcentral diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on yc3tu ul:5k)lx x*6wca 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 a sli0pkms x w9 6qmadh 0135d n-xpf22wqczt 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 iljkp7rr3un.evw./y*x fq9 0r5 2dokq.)m jg ri luminated by 450-nm light. What is the width of the centrmku902 iq xny.vwp5qr3/fo gj..*r)r d kerj7al maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wave e4 ./zh)sjj jboyiz di,15c8glength 653 nm falls on a slit. If the angle between the first bright fringes on eios) j/1d ecij.j,h5y8zbiz4gther side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen ;c* mqqej/op rl-y03w,l(lmx2.30 m behind a 0.0348-mm-wide slijq, pcl3*mlo/l r0;q(e m yw-xt illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a sin9ck gqh8ir8 a6zh6g .st5hil(gle slit, the first dark bands on eit9ari6hhgtk zhqs .(85i6lgc8her 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 falls ld b(dfz*b+ 5son a single slit, it creates a central diffraction peak that is 9.20 cm w d+bl5s*( fdzbide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light zi:8*l cu;ua 1hnkeh 5so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm18*ehun;uh: azl ci k5?    cm

For a given wavelength dfl5d-z5o8 ib $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a lw ,x/d ;l/6qwo+ amhcsecond-order maximum when falling on a grating whosh,l+ax6c/mlod/ ;ww qe 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 ir1z):l:wml-k0upz v mf the third-order occurs at an 18.lr : v1k)pmzzmw:l 0-u0$^{\circ}\,$ 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 diffraction grating ioyft/ye25j-;mfg 4 (lhl,q5 mtstk l- s observed at 4otj-tkg mllhffmsq/ ,t(e2 5y-5ly ;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 h wkgcn 124rzhd/ls;+k.v j 6foas $ 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 a2q0/ a/ *pldxokfp;np $9700-line/cm$ 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 gr6 gilrp;ydwv;e1sc9o++5.qg aovo7 x ating with 6000 lines per cm is illuminated with 633-nm laser light? rggw +dsxpvoe65qaoo7; .;v19+cly i Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of the c3fc4 rn(:nuc )47axxjl ckd1 jvkz9* n 7a.nwcentral maximum when white light is sent through a diffraction grating. What is the maximum number of linescnwnj*au4xfxn (3l: .a1 7cj nc49kk d)z7 rcv per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a graeqi3tf4 eb* s(8hqag 0ting with0qit(b*es8eh gaf3q4 $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic lige0 d00 mwh3xqjk6gu(5nr1a x fht 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 spectruxfmx fz+ / g lj01dg ts-1nbd*oi,j0r7m lines are 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 tq7;t;p; muu rxhick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by white lighu ;rp;m;q7 txut? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8yl /0,r xe;4je6ce zvml;u(c6 xepbl6 if the glass plates are each 26eb0r ey(e m z/ ,;;6vxul6c4 le6xclpj.5 cm long?    cm

  What is the smallest thickae/b he: w6c/qrta7a 4po ,;f:*xzugrness of a soap film $(n\;=\;1.42)$ that would appear black if illuminated with 480-nm light? Assume there is air on both sides of the soap film. $t_min$    nm

  A lens appears greenish ye/8frxi-9 l8z hg6 kcuellow ($\lambda\;=\;570\;mm$ 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 ringdcm( yo1av/xiol00 , as (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 , 0a1alo (dm/ixc0oyvcenter than the edges?    $\mu m$

  A fine metal foil separates one en),v5g1 nyagz9u7 urjee k(e3 yd 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 each ee 3ur,ejeznyg)uyg k(5 1av97 nd). How thick is the foil?    $\mu m$

  How thick (minimum) sl/wy c/xmsb,lzi 7k 7:hould the air layer be between two flat glass surfaces if the glass is t lml,ik7w/b:c/xz 7y so 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 stolen cx 0kn:7da qziiw84y+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 alcoh g,nhsk.(++3v lgmja* 1czwij y*dz*gol $(n=1.36)$ 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 im8i d sjn 4c-q6n*nl-uumersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to ndj i6q 4snl8-uc u-*n2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometeiu, 7z)m:r olnr if 644 bright fringes are counted when the movable mi,m :izrol)nu7rror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. gs;r2a,g +9)t b8toxjntljb 2When 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? The wavelength of light used ig9gn22b oltt; rbtj a,8xs+)j s 589 nm.    $\mu m$

  How far must the mirr adpmi *g:/c.aebr *w(or $M_1$ 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 e 9v bitvia1ds;o:(8uz3 b e)o(Fig. 24–59) passes through a small glass container containing a cavity 1.30 cm deep. Whe(9siadv z 8e3beo1uib t;)o v:n a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orienma 0: dpe-8;kt 1xlqnrted 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–glass.qnp)(y3j a9vejlih 0 $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if a ;a1t ,zqy4y lj9dep:the light is hittinj;1 dzyte q,9aap4:lyg the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so thatn obtwa 1-j26t4aan//7s-;m jt8kc,ece udpd the light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequene;7ote uas1m2cnb -/dj8n/-dkcp64w , att ajtly reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polarom 6ckkys +*r-l/u .piqids be placed so as to reduce the intensity of the incidentiqlr /cmk-u+6 .py*ks unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orientezk fhk*4:)w red 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 orientedb1;, lafg,2 tefo0 lxd 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 arlv4o *f) wd)hngle be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflectionr )df ov)4lw*h, 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 Polaroidc/bvwl v;:-,y cyafezpb5+ wr6/e w x- sheets, each of whose axis makpcbf6z:we +v-xb y w-/,/v;a yr el5wces a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 9 6dlxl7p;udzbh r3d:doy)und1 b;: a$ 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 way3d x;aqld,g/d 8mp k4ves reflecting from mountains or airplanes can interfere with the direct sign4m,8 dpydd3xk;q/ l gaal 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 wnr) *t0biow8 mh2n rsiji99yrs;-t*sources passes through a diffraction grating with * s-;rr9nw*i njytm8t)h o0w9brii2s $ 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 apart. Thpr2c8jqzkh)w39m fh 2e screen is 1.70 m away. A second source of unknown wavelength produces itrh )2j8h2f3p kwczqm 9s 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 beuh0hos 5 7t70e;kbv sdc54 qtroadcasts from two 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, perpendiculac e0t7u7se5hvd 0skoq5;4 bhtr 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, and blfwtsdf5d 3/* c(kui(d5f, abyows a whistle of frequency 750 Hz. Ignoring reflections, eu3yki /bd f,(fwc*s55dtdf a(stimate 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 muvnnjyie. d)18wq+vro+f6 8single 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 l ll.d0 )7pr:njkpklh )ines across them. When normallyl rlpn)7kd) kj .lp0:h incident 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 centimeter must a grating yexpe1x8:edv xoa2vbgs86 2 : have if there is to be no second-order spectrum for any visible2a eysvp vg612:ex:bxo8 8e dx wavelength?   $ lines/cm$

Show that the second- and third-order spectra of whiteqwacuz0 8 4/z xt5:83ju,fgnbfy8wt i light produced by a diffraction grating always overlap. What wavelengths overlap ex,wtb0ty:az/8fu48nz 5f uqiwxc3g8j actly?

  When yellow sodium l81)fz 5/hml i7eg du- vy axriob2-j+vight, $\lambda\;=\;$ 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 digwzq0 ;fid6i2j3n4fx ffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam cofq 40nfwd6 ixig23;zjnsists 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 mateoznr -7a .l ch:kr1ev+fa/v(lrial 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 f v7kaer.zl+n /(:a1hovl rc-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 shx-9 muj-ql00 g r e67zhvx4uary5n.yaeet ofq6zxxj- u 7 ag5.lrur- ane0yy9 v0m4h plastic 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-refe92;i qopotx7qe1:u//aqf vslective 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) thickh v8 (0-lvvob41r3 joe 7pamowness for the air layer between two flat glass surfov1 a (pvhovj43 l-owb rem780aces if the glass is to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitb ,z: :n ,goue6xbg*wpj5ql/)i ; aqiuted through a thin film layered on a flat piece of glass. Draw a diagra: /a5g,l:ngx qu6, eubwi o;jp bz)*qim, 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 Sun when light reflecting off ad/t b7lk30efqp -9iei smooth lake is polarized most strongl7pek -b9ift/ ldq0e3iy?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so u, 2t;rx u2zred: w/x1a o5exfas to reduce the intensity of the incident unpolarized light by an additional factor (after the firstdzx uxoe25a1:;t,wr exr2 f/u Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polariqkpw ,56 0l:wi:fx)1yoccg sze;s.u vzer sheets whose transmission axes are at right angles. A third polarizer is placed between the fir;z6uk1cp 5fy w egw:,q)ssvixcl:0 .ost 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 vrke, gxy;f0u e h 8sb0p8lqd;hyg)6q 3ertical, 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 s,5muxzf.k/p) n3 wajslit of width 1.0 cm and is pointed at the Moon, wj/35m ,fx s)kzapw nu.hich 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 polarizers are each placedm3i-l 75ttvc kzz5g8ooe. d7q 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 eza8e m9rda 7g;oyt1pb1hc+, $(n=1.34)$ 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 p,r 8vovkwvrr., hb 4jwl/hiv9lk0a; 5hase with each other. They ar .0il9rb8/, oawr ,vkhh;l5jvv4wk vr e 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 and 650 nm, enters ajwq04uc6( i oa silicate flint glass equilateral prism (Fig. 24–58)q iw6ujc(ao04.
(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 ha)ciw3nve8a9p s 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