Does Huygens’ principle apply to so w ucxc g3iv (m((etx:u1)l4ovxn)7 sound waves? To water waves? Explain.

What is the evidence that lighty dcl1(1rjy) alrifii ; /)i,q(g;ozh is energy?

Why is light sometimes described as rays n ,ig95kiov9 vand sometimes as waves?

We can hear sounds around corners, but we cannot see around cornerum at(yz9)s3otxk7s4 s; yet both sound and light are waves. Explain the di3 osz4x79u (t)kaystmfference.

If Young’s double-slit experimduge mwm8r 7,;njxujo*ji41/ ent were submerged in water, how would the fringe pattern be ch1eu/mrjo7;dj ,nm* 8xuwjg4i anged?

Monochromatic red light is incident on audew(siz684x x:4x og double slit, and the interference pattern is viewed on a screen some distance away. Explain howsu(xd 6 xzix:o844e gw the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the s.*+9cays52t:i i v 8fa lzpr4 vruozl.ame source destructively interfere if their path lengths differ by how m+ulacif z .vyo5ts8rp i2z.49 rv:al*uch?

Why was the observation of t4 ig)7,nw) mklba 9skbhe double-slit interference pattern more convincing evidence for the wave theory of light than the observation of diff bb)nki974 ),wgsamlkraction?

Compare a double-slit experiment for sound waves to that for light waves uak mio 3/n0bzg-ura,::-ox e. Discuss the similaritiesu-ukob g 0e,:/xn3zaom-a: ir and differences.

Why doesn’t the light fro21w6lwom lyg/- og4d mm the two headlights of a distant car produce an interference6g w o4wydo2/m1l- mlg pattern?

Suppose white light falls on the two sli76kxedi lm3yt39igv vaq09 v( *xpqb5ts 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 on the scre6 b5a x09ql dv*vpex3m9v(gykqit7i 3en.

When white light passes through a +jjf8)a/4m2bk l s5 t en2baczflat piece of window glass, it is not broken do/)jtks lz4 28f2aa5+m ebncbjwn into colors as it is by a prism. Explain.

For both converging an nvc5f*zc*0 k 5wrct*md diverging lenses, discuss how the focal length for red light differs from thacw nftr5*z0cckm* * v5t for violet light.

A ray of light is refracted through tho9 jjje7 rb,f(ree different materials (Fig. 24–55). Rank the materials according to their index of refractjo7 f,eb jr9j(ion, least to greatest.

Hold one hand close to s a ybjrd)u/ )/(vx/ cyxy99akyour eye and focus on a distant light source through a narrow slit bejy /ay sr )dkcy9x(9/u ba/)vxtween two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole apparvb hxkc67mr x+.qn8:x atus is immersed in (a) water, (b) a vacuum, inqbcx:.7 xnv 68mrh+k xstead of in air.

For diffraction by a single sl ) ymerylhctee/5r1:.1l q7i iit, what is the effect of increasing (a) the slit width, and (b) the wav/:. yyrqele7 tmirl )cie15h1elength?

What is the difference in the interference patterns ks y6-p)tqcj ;3*qpbe formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what:fzlee d zns0r , 86vdbii21p/ is the advantage of (a) many slits, (b) closely spaced slitsz0p:fl dz /vi86seib1 2r dne,?

White light strikes (a) a diffraction grating, and (b) a prism. A rainbow appear*8l4etbw:5kbsuxux cmw;p1u9z+ zu ,s on a wall just below the direction of the horizontal incident beam in each case. What is tht*uwuz lpb c :mwxuz e58,9b+xus1k;4e color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, inik7 3dol3htq5ac n 2v 3kq/nr+cident normally on a d+73 3kv o tn/ihcqlan3kq52 rdiffraction 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 bub+11m3g wknel 9idj h:nble and not:i9wmn jkn 1h3l1gd+ e for a thick piece of glass, say?

When a compact disk (CD) cgf/ 72objg)jq): *wgzhe i3z is held at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. Whatzj)z)*oc q 7gg3e/:b f ghwji2 would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer togeth bs rr1y9sx x 11f-3ijkykp 1e03vpyd6er farther from the center?

Some coated lenses appear greenish ye /9) c(dcgbqv(lv6ovillow when seen by reflected light. What wavelengths do you suppose the coating is designed to gc((q6c b d9)vilv/votransmit completely?

A drop of oil on a pond appears bright at its edges, where itsdc ysio*0oblj;5wf/)sq8 ol 4 thickness is much less than the wavelengths of visible light. What can you say about the index o/ljd b)c0wyqis s*of4o l;58of refraction of the oil?

What does polarization tell us about the hj sw7)gj0s3m: ub. lrnature of light?

Explain the advantage of polarized sunglasses over normal tinted sungln1 134o,cxf auqfpqq 9asses.

How can you tell if a paiw9xcnj 95*m wjr of sunglasses is polarizing or not?

Two polarized sheets rotated at an ank9n5o qi*lo:q-mga qs:+n bl5gle 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 atmosphere,s ch/m*, jfb hyw97kt?

If the Earth’s atmosphere were 50 times denser than it is, would sunlight still by0 xx/ a1su8esx:+ugx;nu1jbe white, or would it be u eu1xbgs01 u/ +s;a8xnj:xxysome other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-orderww ;3-7hkpu+9ve 5zwm)k x nzt f uhpe7k m kwnw-z); +v53wx9ztringe 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 observedrztcbhq7j;*:x lh 7 l1 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 apa:o+ 9 xne45)cj* vvufln g2upgrt. Successive fringes 4+voupnce2l ) uj5: f nv*gg9xon a screen 5.00 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 w9i+c7oryuz50fn 4 vb favelength 656 nm, falls on two very narrow sl rzcuivfbnf 549o0y+7 its 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 slit:nv+r:djk .ma mp 10ags and produces an interference pattern in which the fourth-order fp.jkm1g0mdarav: n+: ringe 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 light passes tbhj54g68mi o ehrough two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 m away? 65o8 ebm gi4hj   mm

  In a double-slit experiment, it is found that blue light of wavelengt; 80u+7 0nf7jkah qyq,7ukyztar.5pphq1wav h 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light wou,af.8h0yzpnrk7uq u p0tah7;k17+yqqj va5wld have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings 2z j*4 nbtvane fs cl;z861wdr,g;if8 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 wjn;r8d8, 2*ec; tivf zfzlwasg4b6n1 ould there be little or no wave action?

Suppose a thin piece of glass is placed in front3:r) r)tr ffse of the lower slit in Fig. 24–7 so that th)rftfe3 :r)sr e 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-order maximum for lightgl8vkf/qtq- hr z/x 69pn- p6g 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 tq/9l-kp g 66/ tfp-rzqvxh8nghe second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. Find the di1tx; r.wu dx9q9z;s/u fz lg7istance between adjacent bright fringes on a screen .;gu rz twxx9z9quld i;1 /f7s5.0 m from the slits.    mm

  Light of wavelength 48jw, qg60x3hb)tr8 cg b0 nm 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 (nb pra 4v25fvd +,rpqv6=1.60) 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 dar+6,r4qpb varvdfp5 2vk. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (i c5va,,e )0fjvkzuv 1700 nm) exceed that of violet light (400 nm) in silicate flint glauek vvv,5,0jza i c1)fss? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60.0gf5jc;vpb6). ev d) qk0$^{\circ}\,$ 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 8mlc 3tfu4g8nrtn da6 4 1t-ixtwo 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, whom5 kfmw :ki(om3l7her2xc ), at is the full angular width of the cent5mem f(, 3: whlkirx k7m2co)oral diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that 1,k6vuo0d v,iwohbt: 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 tt ;/f aavjpg.2h0-ojb hat 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 wio:y 3 *d:lu fgzr. hgo)wef9*dde is illuminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern z * :gdh9*ue o.or wldy:f3fg)on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slikxj3w41p8lmv* d hv0 2amh,ew3i;ck wt. If the angle between the first bright fringes onkx,4 klm e* am wh13di8; 0cj2wvpwv3h either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffj vu;f(67ri xaraction peak on a screen 2.30 m behind a 0.0348-mm-wide u i(jf7rv; a6xslit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a *cxq:1rao,xs single slit, the first dark bands on either side of center are separacrsxq,a:1 x *oted by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a qxj+(lu/ 9kwvh7 hs:r single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wi rvjkqh(xul/ sh9w7:+de is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction ma6- r 9jl+opb-zt/h qd9fmobn/v0 m8qkximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum +k6l/q/dnoz9- jomp9bh mvf0-bqr t 8 for light of wavelength 420 nm?    cm

For a given wavelength pu:*ue t(st+;ypu,te $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm lcx 7equj0nlt*x*cs , h 4lm9g6ight produce a second-order maximum when falling on a gratixt**nx0 qm6,ljlc4h gcsue79 ng 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-:ux wk u6u7 0**dxyrymorder occurs at an w :7uxy*mu6kyrd 0*ux18.0$^{\circ}\,$ 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 lighti ozk1:q ap3w2ky g/a; falling on a diffraction grating is observed at a2 y: a;wzioqkp3/a1 kg 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratiny+gphgv zrr81 t5h8x0 q5qmz 2g 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 normalns ;46pdftj56 u7myxl ly 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 spectrajxgka4:r d)p-(v( tl al order that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal incidenxrv ltj)-:dg(4apk(a ce.   

  Two (and only two) full spectral orders can be seen on either side of the cen3hd;-s w8pbba tral maximum when white light is sent through a diffraction grating. What is the maximum number of lines pd -s;3abb8hp wer cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengthl+vbj,56urhb- zatciu 08 2eas from 410 nm to 750 nm falls on a grating witheu,+ 0ibb u2ar6z-ajt5 hv8l c $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whica97 zrpck *:dbh produces 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 are a:k2 c.i wvm+wmeasured 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 n; ov3kbf8: *uh gkj.btm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by.bt;8 :kk jbfuho*vg 3 white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the 5cu nqx);1gci(n o4zmglass plates are each 26.5 c; 5nnc1mg) xz(qi4oucm long?    cm

  What is the smallest thickness of a soapn9 t4jn5 l-hbb.hr ggg a-f+5z 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 yeljzb (uadr f58t:/toc;low ($\lambda\;=\;570\;mm$ 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 2c . 4suaz/k*)tdpas -m qih3s31 dark Newton’s rings (not counting the dark spot at the center) are obse/suzkh.c-sspa 4d* ) t ima32qrved 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 the edges?    $\mu m$

  A fine metal foil separates one end of two pieces oh+8 sn8j jt s; :ws7xrpar-z(kf optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark linesjpjr7rshwk(8x:tn sz;-a + 8 s are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two gn/*9e /rmj/ pqgt(wsflat glass surfaces if the glass is to appear bright when 450-nm wgt gjpsm(*/ q9/en/rlight is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a sd9 ; wgl dx0.fdbf3+xstolen diamond $(n=2.42)$ is submerged in oil of refractive index 1.43 and illuminated by unpolarized light. It is found that the reflected light is completely polarized at an angle of 59$^{\circ}\,$. Is it diamond? ----待选择----yesno 

  A thin film of alcoho)b dy nl)vsb.;l $(n=1.36)$ 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 immersed in a liquid, tj2h* ma/t .07iva aopehe diameter of tht ipmaj e*02aha 7o/.ve eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light enteu6ew9 z 6aizji.,feg;ring an interferometer if 644 bright fringes are counted when the movable mi 9uwz.6i;, f6 ejzeiagrror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirros6l ( 7brzzwz/a:m:dz r of an interferometer. When the micrometer is tightened down on a thin metal foilmzl:6:z 7 rzdwzbas (/, 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 is 589 nm.    $\mu m$

  How far must the mirrorpxo39)1rn ql o $M_1$ 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.xhe pl :nixq64e*.:no 24–59) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm.x.xnelehn :pq:6* 4io Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientj26uf+bok7 m7w9kxpi*h.;u z z1pnqq ed 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–gla yuosk71dqnfi6 30o(y ss $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in wate*x;/ff6s 9o(r i rcjlhr if the light is hitting theo*c/ j;9hxs(lrrffi 6 diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximus2zjomng6m2 v9 y/ (ru7)nk wem. At what angle should o(2 wyrumjvz/n7gm96ekn ) 2 osne of them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to redus mi)vs(fw*x4 6zw :8h0tun7.cxpyxhce the intensity of the incident unpolar0c i :yw*zssfvx.)6xnh4ht m 8x(upw7ized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orienta d4ol usl*xpk5lsz0)g,q z/9 z69e sved 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 aiu 4(b3vmlp8x t 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 refd d plq4px;*va4m +0ynlections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewsteqnd+0p4d avmyp *4x;lr’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 fiv)p-.rmmt( sbnuia 66j e successive Polaroid sheets, each of whose axis make-m.) ni stumr ba(p66js a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 2z/e ainl5k .b$ 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 reflectifc.shlz8x *dg -h0xnn.r/ (os ng from mountains or airplanes can interfere with the direct signal from the stazs x/xhgd..0cnrh n*f( ls8 o-tion.
(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 separt0z c -*dhq,gn* cgn)fate sources passes through a diffraction grating with gqghfz) n- t **d0n,cc$ 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 tm+y*px dgp vjqx dx0((49ttu; hrough 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 closer to the central maximum than the 590-nm light. What 9v xp(jpq 4+(gu ;yx* x0tdtmdis the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two identical antennae asesr;z of/3-uler7 s95 no31a b7cyl jt the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is jr7y ere9s s-f3 1;bzl3l5u/nc sao 7otaken 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 wello wm-awqs72ltsq3g*s gol15, back from an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the sq o,ws5l31*7twqmgo -s2lagplayground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls r:h2 t6rwp* me*qr:lhnjq l-ih8)7rs on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetlecv.s2ku o hq/j w3eb;.pcwa:x /f3*bsacxb1/ have a series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the bhwjcs:baw;b/ qk. xo/.3ps 2f31a/ *cvcux e 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 have if there is to be no second-oric3k7h (nt/p rder spectrum for any vir ncp/t(37kh isible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light pro1gf( 5gb6k vtoduced by a diffraction grating always ove v5kftgb6go (1rlap. What wavelengths overlap exactly?

  When yellow sodium ligw q8z , sggz(p7lhra*6ht, $\lambda\;=\;$ 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 vo l47 uqu+sf2*tq1w ugiewed on a screen 2.5 m from ths2gtqwf u7ol *1 q+uu4e grating. The incident light beam consists of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clear material if a minimum of 150 nm thmj3q9. i9)fvd /jen:plf-zrm ickness of it, when laid on glass, is needed to reduce reflection to nearly zero when lizi-mjr:3 nmf/9dfjl) ev 9q. pght 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 thinz9fhs4q 4py)v+s4;sq g) vw ju sheet of plassq)zu;j q)gswv449f 4+p yvshtic 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-reflective coatilgla: japqi7 yp uvi.kay5) n28:7k5xng $(n=1.38)$ 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) ov7:v .+ucyol z wx4h-thickness for the air layer between two flat glass surfaclv7 owh-4.+ zoy u:vxces 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 transmitted through ao1fiu +ky/b*d v2odw1 thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and descriv k1+fwi d yodb/*1u2obe 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 f ; 6jrmw* i(q31vej xzf*y1itoff a smooth lak1fem ; 3tzf*1jq yjix*r(ivw6e is polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two wel,fjs7bq5 8 Polaroids be placed so as to reduce the intensity of 7f wqbejs8,5l the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axeswjngr p54 n1q; are at right angles. A third polarizer is placed between the first two so that its axi ;nwjqp 54gnr1s 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 wite 80s;j,o u8;cti5dyvhg rh w8h 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 oduat b:xr s t,31) b6e)a+nlxqf width 1.0 cm and is 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 bld),rbtqa)16 x ns e3x +uta:He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers arxw)p 7sj oy3j(2oimm)tlq /4x e 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 1kkxn q z9t,9z$(n=1.34)$ 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 phasegq ,-r f13zsiajv w79n with each other. They are,-1jq9 asfzn37r gviw 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 s+m r:,eam zn9t x8tpaip 0r3:wavelengths, 420 nm and 650 nm, enters a silicate flint glass eq9s,pmxa:t0nrp:r i8a3et +z muilateral 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 onko3g f 7ed6ojfq q6hwd:d0 +ri6/sutg0y c+x;e 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