Does Huygens’ principle apply to sound waves? To wate ;i:1afk zm0dyapskzi,3rr3 j4g+( car waves? Explain.

What is the evidence that light: m7t9 bqsr9hw iqb,(o is energy?

Why is light sometimes described as rays and som -39xdqz*s /va3tetnxh5lv 2vetimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet bothcs09 rd)j 5nkbjr1 0uj sound andj1drn00 9jjk) cr bu5s light are waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, -dk3 ;/(yby q 8ethben 8lrvsxthy228how would the fringe pattern be chany 283s2;xvb8h h8 tdkrt lbe/(- eynyqged?

Monochromatic red light is inciden;zv bb aa3 koy 094ip(z5ix)ktt on a double slit, and the interference pattern is viewed on a screzxaopbviz)95 k3(kyt0i 4a;b en some distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from tlmw: am5x 5znc:n7xusj)tf*,u b+8se he same source destructively interfere if their path lengths differ by j)fszl bat+uxem57:xs:nc* u ,85mwn how much?

Why was the observation of the double-slit interference pattern more convinci43 (grr 6sn +;kyhb*ehokia* fng evidence for the wave theory of light than the 43r ;*f*r6 (gsbhoeai+n hkykobservation of diffraction?

Compare a double-slit experiment for sound waves to that for lj q8tm5dimr( l5lq7 uo3a n6-cight waves. Discuss the similaritiesqqlcma7ru oj5 5 83tln( im-d6 and differences.

Why doesn’t the light from the two headlights of a distant car9y 0d :r9yx nkj53cuxc produce an interference 5yyd:xn993 jcu 0k xcrpattern?

Suppose white light falls on the two slits of e(e jl3ng6:i e2bzqj0Fig. 24–7, but one slit is covered by a red filter (700:glzq (3j ee06i2njeb nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of ce ** ozk g)yhx6s*1fqwindow glass, it is not broken down into6ygo cz)ks1h*fxq e** colors as it is by a prism. Explain.

For both converging and diverging lenses, discus,6t tmg9akmt2n( (ppep iz*-ss how the focal length for red light diff(kpg92im -* zam ts(pt e,nt6pers from that for violet light.

A ray of light is refracted through three different materials (h ;9o6k*ymc fjFig. 24–55). Rank the materials according to their index of refraction, least to great f* h6c9m;ykjoest.

Hold one hand close to your eye and focus on a distant light source ynbrzq9a-4hzn(avd )*4 hhb, through a narrow slit between two fingers. (Adjust your fingers to obtain the besb4hq4)9 *nahr z,nbz(-dhvay t pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a si4igd(*lyfgjg7v lfk rq z.en,1eg0, 3 ngle slit if the whole apparatus is immersed in (a) water, (b) a vacuum, insz *q3 ,kge(7leylr igd,4fvg.gfjn1 0tead of in air.

For diffraction by a single slit, what is theg/kznx +4(k5e(p awv a effect of increasing (a) the slit width, and (b) 4 zkx+kna5(va g/(wpethe wavelength?

What is the difference in the interf 73;4)8pz kdekfudhb eerence patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantagna7ubv)32wt ue of (a) many slits, (b) closely spub 3 wtu2v)n7aaced slits?

White light strikes (a) a diffraction grating, and (b) a prism.e8.sjte7:xn+wg p -js A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. Wwjspsj-7ex 8g+ et. n:hat is the color of the top of the rainbow in each case? Explain.

For light consisting of way g cw5x sazx*, k:2dv4),mskqvelengths between 400 nm and 700 nm, incident normally s: )m*,,kc d 4y5xakqvsgx2wz on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a soap bu l,+0 lxh2dptabble and not for a thidplx2t0 h,+lack piece of glass, say?

When a compact disk (CD) is held at an angle qs epb(2h)4db in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you )dq2bs4e(h bpexpect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther fro4 mvt5i-0..sdnhtb cy m the center?

Some coated lenses appear greenish yellow when seen by reflect x 87rnf by0:dc4 eadyf88*fkped light. What wavelengths do you suppose the coating is designed to transmit complete8f y 8r*4f8p7byc0fkx:ndeda ly?

A drop of oil on a pond appears bright at ih-n ty7gb6p0c: (ux tzts edges, where its thickness is much less than the wavelengths of visible light. g:p6t x0tb7 u-yh cnz(What can you say about the index of refraction of the oil?

What does polarization tell us about the nature of lighac6u8 i hehbrf0c72o4t?

Explain the advantage of polarized sunglasses over normal tinyid ,jev7 bi,)3gb:z:akida : ted sunglasses.

How can you tell if atniha r j k3k.t)7:,bg pair of sunglasses is polarizing or not?

Two polarized sheets ri8 aff nih4 nm)3jk)y,otated at an 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 mj v6so-w, u 30lg:q- :ewvf:p3ayarsEarth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is, woul)2b 3p) k8exo/dsdgsdm e*q b( i08qrnd sunlight still be white, or would it bqbxks)(/o3q m*dr ien) 8p2e 0dgd8sbe some other color?

  Monochromatic light og 2,g+39 l,gbj cvzwqfalling on two slits 0.016 mm apart produces the fifth-order+gcj lgvowg,b,9z2q 3 fringe at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm lal k .6.*qqec+wfx c;xa 7j2ytqaq.+dight 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. Successive frb q p:61g 8,81bjhpqzk o4vcbpinges on a screen 5.00 m away are 6.5 cm q1op z cj,bk6:bq 8gpb p1vh48apart 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 Hzp-czl+- p2fa5ncz 5 qka9 plaid4* j3e-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How zp p l3+*-f5nqia2ac4 k5p9az-c z jldfar 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 if6w9gxyw.t7xfa5q06ej x r*bnterference pattern in which the fourth-order fringe i* .f7bgy5rja96f 0xt6qexwx ws 38 mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, howjsnc xr:n6*va;+fh a2 i6rn)z far apart are the second-order fringes for these two wave;i+j6n rza6*x r 2 vn:nfsca)hlengths on a screen 1.0 m away?    mm

  In a double-slit experiment, 0s c zlkw:6hld 9s,z) 8)iaf 2y6nvjxuit is found that blue light of wavelength 460 nm gives)80jl9zlsnv ywhuc,f:k 6xia26)d z s a second-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 flzrk8l6:m4 dzlq0 c+z6 ip+s 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-thro4:6l0 68kc zi + lfspmzlqdzr+ugh” direction would there be little or no wave action?

Suppose a thin piece of glass is placebir;8jywox wt,b70m3tn vp2-d in front of the lower slit in Fig. 24–7 so that the two waves enter the sbom0x- 8j7ib,p t 3r;ynvt2wwlits 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 ona+t/5- 12wbgyeqxi x f wavelength 500 nm is located 12 mm from the central bright sp ab1/2eingxt5-q w +yxot 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 of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminatu6ev(nuo t ;u4m,x-v fed by 544 nm light. Find the distance between adjacen(uumnev, vtf -46u o;xt bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air0 o)dljy/mlhijct 22- 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 plastic65u r/ifv 5w+l pm;xdc (n=1.60) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen,vwu/x f+6irmc;5p 5dl instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red lj8;9j-fx +zaa6 /d v mjhsaob3ight (700 nm) exceed that of violet lizfo xaj- jh 3;9a6a d/jm+s8bvght (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece kkb1/6if sqg, ,w5ondof 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 cozf+8rvk chkpfdx 0z53ma 72qqu2 /ca /ntaining two wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm wide, what is the ff1bjc*r5 m7 msull angular width of the central diffrc7rbmf15j sm *action peak?    $^{\circ}\,$

  Monochromatic light falls on a slit tha itvtdw7(t /:tt 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 slit that1hkwowe 1 (/x i8vybzus.(-j q 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. Whath/,umswlpg 59 ys;c ss.rn35-0ufzkz is the width of the central maximum (in cm) in the diffraction pattern on a screen 9/ rgzs0 .; c-h35uszpl fsn,mys5 ukw5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If1 :f i-snoeo,f the angle between the first bright fringes on either side of the centrao oe1f,:-fin sl maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction p+ hlc9cmiw *t.eak on a screen 2.30 m behind a 0.0348-mm-wi9htcwim*lc .+de slit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dark band2* ow0- vbyxtbs yb0t2ov*x-wb on either 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 on a si;upf xhesl4 a5jp)5fp 3eo k:-ngle slit, it creates a central diffraction peak that is 9.20 cm wide on a spfl4 5pef-aek 3 us)h ;:x5ojpcreen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum ieb1a w(;vvklk lqi,4)s 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for lighl(; , lbieq4 kkv1v)wat of wavelength 420 nm?    cm

For a given wavelength 4z6gldd( ozq+te 7, wf$\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-order maximum when falling on oceh;k(w6 z ar5h0;tua grz; 0thahuwr5o;e ( k6cating 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 thirl 452tu(ure gkd-order occurs at an 25greuk lu4t(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-no2fsc6- )voxymj iq4w7d,4o9byyvmn0da+ +v m light falling on a diffraction grating is observed at qv2fi abjoonoy474 + ,x ) 0d9d mscym-y+6vvwa 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating has1d jjcft3qt ;4 $ 6.0\times10^{ 5}\;lines/m$. Find the angular spread in the second-order spectrum between red light of wavelength $ 7.0\times10^{-7 }\;m$ and blue light of wavelength $ 4.5\times10^{-7 }\;m$.    $^{\circ}\,$

  Light falling normal,:ow03kpg cj/gwox ) mj3 hy,jly on a $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order that can b n( (t,tdlln.me seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal incidet (,mlnn tld(.nce.   

  Two (and only two) full spectralj/1 xwy6: :+ulsclxs dy..7gjliyc4w orders can be seen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm f:w/+xgl4wj jcilsd. y ysxu.1ly:6c7 or the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 o epgb+ y/kj)q3w ,hq1.fdm,j nm falls on a grating withp dqy,3/ fb )h,eq. m+jko1gjw $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromauf cf/lw;eu ev:7lo,ii 1is/4tic 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 line (8n(f);mf xjm9n+w:gi xs tbjs 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 u 4lp2duyw46 navp v4d*jh 0;y120 nm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by whit y;6dlu4dv w n2ah*yp0p4 juv4e light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if 2 p):djtoc y9 bsq+e6nthe glass plates are each 26.5 cm longy:o n2jde )9+tpb6s qc?    cm

  What is the smallest thickness of a soap five omk3prd *r( 5c8 ru69 (sg0:z 8jptlidgaw6lm $(n\;=\;1.42)$ 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 ye63+ l 6cr6v fx+o vrv lu85m+qgsvjne2rq b,6ellow ($\lambda\;=\;570\;mm$ 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;jy0 bkr: hjd9 the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is the center than 90:ryjj bk;hd the edges?    $\mu m$

  A fine metal foil separat b;o b-6 swsip0rmi*9ac go-/ifjf36res one end of two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 darsma sjifobr0-6cwoibrf6i9-*g /;3 p k 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 surtha 53fce 81scfaces if the glass is to appear bright when 450-nm light 3f 58stc1ace his incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, sus uw kok7 1x9g(n1eravvsy76x,pected 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 alcoho9nx )6yt3 +vx4; zqdpqjhs7wnod,,o ql $(n=1.36)$ 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 immerb2 3ldq-zkqff /d*)xw sed in a liquid, the diameter of the eighth dark ring decreases from 2.92bk/fx3qd )- fw*ql2d z cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an inteb :kjv +6)8kl.b6u uafdkgo z:rferometer if 644 bright fringes are counted when the movable mirror move6)f. k6du bj:ulza+ :kbo8gv ks 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an )-1 ,5- fxmb vorujqdqinterferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, x ,5vjd rf-oq1 b)m-uqcompared 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 mir6dgdf pked rxk z,*bz3u :q,t2h+jl(4ror $M_1$ 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 interferomezi, uf*tm7i 4aeyqkbz )*7p)mter (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 cont,ez)u47*iq*mb t)k i pmyz7faainer, 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 oriented at 65i.ykbh6e 4z)z$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–glaq 9 :7nuveg7fass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water ifdde)b u9e34ni the light is hitting tindd3)9eeb4 uhe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the ligoj;l vm/ sn2sidqry/jrx,:,djq 8(y.ht passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequently rx,/smsd l,j:djq8yr;vry (i.onqj2 / educed by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as/vksy3 f x9bmuu40,u w to reduce the intensity of the/u4fwy ku3s9u0 , mbxv incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at gp f8*4un/fec40$^{\circ}\,$ 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 atbzvh*;d1t sx 31 yia7t 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off8akwizt *h8a/xi5hz 5 the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above thahi/ at58z8kh5wx* ize 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 Polaroid sheets, eawmf(z wa1s/v-swci;bywm 017 ch of whose axis m1 vb m wyz;0 -s1(/cwa7mwiwfsakes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength y -*rdg tmkn9xjbpk pk.)h337 $ 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 refle:rro(gle u(h7 rbk8) 6yt soq6cting from mountains or airplanes can interfere rr slo(oe gurbth86 y67)(:qkwith 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 throubn:1-ciq9*f 1 ljulqugh a diffraction grating with :j1uulf lb-c1 * niqq9$ 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 innw y- m87w j+bocr9-nm passes through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm cljc -rwy- nn+m7wo8 9bioser 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 identicalr6vma 59wrh8g 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, perpendicular to d at its midpoint and extending horih r8m5 v9wg6arzontally 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 .ql+6ellkof+ p n-24bd5c(st0gcxc edoorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflelk c+x.5olfbl2 pe(e+gqsc4cdt-0 n6ctions, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of width Da+0tl59+c fch h)pmz0idse;h at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of paralvk48q 1u rcr 3,f)ghralel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at h r,q)3 r14 ukv8gcrafan angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter066ba+l t,p -3r/0ddvnd8jail gw ter must a grating have if there is to be no second-order spectrum for any 0i,ad8 b66jp/ l0 -ld3+dtatrwnvrgevisible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produc kh-idm3c e3-ced by a diffraction grating always ovk d-cim-33h ecerlap. What wavelengths overlap exactly?

  When yellow sodium ligw e78:qih)zop g/o- :iq8azlp ht, $\lambda\;=\;$ 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 ak *v r9xi0h3cb diffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of two wavelengthchr 3k9*0vibxs, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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/+p3v v-+ncmqb sovhvvpt7 ,5 refraction of a clear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you p/-vvnb+vv,c37qto5h+ pvm shave a choice for an answer?

  Monochromatic light of variable wavelength is incident normally on e4uc jb:8d4lnk 10ois+a ;rhl a thin sheet of plastic film in air. The reflected light i sld+k4ia 1;8cu :ljh 0ornbe4s 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 x x3fl04d ji-mmfxy.0-reflective 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 fo+ pbo6x 0)k)sl2kcm ugr the air layer between two flat glass surfaces if the glass is to appex m)k2obk)ul0 c ps6g+ar dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the lighxrx7 bjga cy 5;y5oy90t transmitted through a thin film layered on a flat p5g x;ayojyc9y7b x0 5riece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflecting off a4qp8r fu 1j6ji smooth lakjpi 6jrq1f8 4ue is polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Poelq.;r5 dbb.q laroids be placed so as to reduce the intensity of the incident unpolarized light by an addd q5ebqbl. r;.itional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmissiyo*32,/ fd. awgahnty on axes are at right angles. A third polarizer is placed between the fg.3 f2tya,y hna*dw/oirst 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 succe /hrtbym 8row dy3b4ha s .jvl6:iw-4/ssion 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 6xk* hp:vy+e8q 3r /z :vlop yf;s3cgjcm and is pointed at the Moon, which is approxir jph;3k6q xvg3f: o 8:+zly s*yevc/pmately 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 i f h( yu5oiv09sqr7t)are each placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap ifip9j +t y s)d-j.h2*s rsm)o$(n=1.34)$ 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 n92f -v no8pmtrnw. .ua1q3b:qy)dl9m 1qabcin phase with each other. They are located at points) cqw3 2n:o1ad9m1m8n9tuvfa.by qr-nql p b. $S_1$ 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, ent o7jdtzb-um8lm( qqrafb3-/1ers a silicatetjro/ b(ba -1 zl3qu8m f-7dqm 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 one flj4mn 7g-ri um+f5a(*ycd j b6zat 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