Does Huygens’ principle apply to sound1pairz)u q+f bcjf7*, waves? To water waves? Explain.

What is the evidence that light;u-og7hzxgw6+ 7 f adob;6t ez is energy?

Why is light sometimes descj3j6 q5g5i o 8uee h2qb7srnm.v .yl9bcpe60jribed as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around cornwg o)kvs)pb;nt;56y ul )6hh aers; yet both sound and light are waves. Explain the differnakpth s )u) hb5l6);yg;6wvoence.

If Young’s double-slit experiment were submuz xkt vs+63 )j 60fk6atxjgm/mkx8. derged in water, how would the fringe pattern be ch36 x8+0kkdmaf m.g/ x)6j ztvuskxjt6anged?

Monochromatic red light is incident on a double slit, and the interferen+o fl9 qm: :).e:gfocwojdlq4 ce pattern is viewed on a screen some distance away. Explain how the fringe f:9gl4qjl+: :foe c)qowdo m .pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere ifnh k8nm-d;)l u their path lengths differ by how mund8 )n-lkm;h uch?

Why was the observation of the double-sliwso8t62h :y,ou)gizl t interference pattern more convincing evidence for the wave theoi)zo,2uswhtl8yg6o : ry of light than the observation of diffraction?

Compare a double-slit ex78y:wy7c/mranvy .(q w5ersz periment for sound waves to that for light waves. Discuss the simi.rser: aymzyc/7vqww58y(n 7larities and differences.

Why doesn’t the light from the two headlights of a distant car produce sm-s xt/cgb rj 96.sf9an interference pa ./gfbrj99 6txcssm s-ttern?

Suppose white light falllrx5.je ,r 0miuis-+ ss on the two slits of Fig. 24–7, but one slit is covered by a r 5m+ri lrsisex. 0j,-ued filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat 6/q5/oy-2-bokhw1i jw nfunf piece of window glass, it is not broken d -2jy/i 1ob6-f ouwnqhn5w/fkown into colors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length for f-su 3vl+9:u6.kst bqfd) m jqred light differs from that for viol -96)bd3.:f+ suqvu mqtlfjkset light.

A ray of light is refracte4twszh99 ssl4 d through three different materials (Fig. 24–55). Rank the masst49 z 4hslw9terials according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source ,. *roo( xpmcnhw1f1-erxk(d through a narrow slit between two fingers. (Adjust ,oc(*1mr efn1( dw.rxoxkhp-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 aps,/toxwo z/t7paratus is imt/7z/tooxw, smersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (vizda8 gf9p3k 9+*pzua) the slit w 8fpziz*a93 +pd9gkvu idth, and (b) the wavelength?

What is the difference in the interference patterns formed (a) by w8ho9ln 1:eo 9lsu*fytwo 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 sliter3 adc.8e;sk2kz l/7d jp0e( a+bxwcs, (b) closely spaced sl7/.leeed3 krp2szwaka8+j0xdb;cc ( its?

White light strikes (a) a dn5p e ,*r3m ;p4zm/ z2tqtxsjuk6+dsmiffraction grating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in eachkje5 s;2sr zqt/ud6+m4mtx*pm3 p,nz case. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incident ds7g5o ukze6w ux 4spy7 gi0c(ish6/)normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your an0 hz7i4gyus7esski wpgx)6 u d(/5c6o swer depend on the slit spacing?

Why are interference fringes noticeable only for 9nlebsr euofd;8 o/.4a thin film like a soap bubble and not for a th es8ol. ;4 unfe/o9brdick piece of glass, say?

When a compact disk (CD) iuea z.ww5j x8r-29,v2ch e4f7 bblpths 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 monochromatic cze2 b vup58et.7 4w,b2hawf9x-jrl h light was used?

Why are Newton’s rings (Fig. 24–31) closeru, 2e(,oupt(uui nqmqv 3 h**mafbr- 5 together farther from the center?

Some coated lenses appear greenish yellow when x9:;r */cq3ymgo/9ua v giqclseen by reflected light. What wavelengc9/av3g q/u*y;cgxi mrlo:q9 ths do you suppose the coating is designed to transmit completely?

A drop of oil on a pond gjuks;xr95. zappears bright at its edges, where its thickness is much less than the wavelengths of vijzu ks5.gx;9 rsible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the natury a3xhpb5q.f6i.3kk o e of light?

Explain the advantage of polarized sunglasses over y;j 8l3stuju/ normal tinted sunglasses.

How can you tell if a pair of sunglasses ilh*/0bgc:) fsf/ gysm s polarizing or not?

Two polarized sheets rotated at an angle of 9 bb x;w3 cla+z 4u:en-bdl2b2i0$^{\circ}\,$ 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 xd8m tfzu/44;vr/ch e the Earth had no atmosphere?

If the Earth’s atmosphere were 50 br ;c th;wq46rn dt8i6times denser than it is, would sunlight still be wh8;nt;4d wcir t rh6q6bite, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart prod 7(uyjor38ts.t0osmluces the fifth-order fringe at uyt(r3j7 .omss8o0tl 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 obse j y+hxh9tui,,rved 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 apakr /) 0(95 npiqnh xesxtpl(6jrt. Successive fringes on a screen 5.00 m away are 6.5 r(p e jl(9kx5qshp)/0n6tnxi 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, 1p wpxw.i4w* swith a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringsw px4. w*ip1wes 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 interfeuem(lh8p6n 4ivgmkd6rmxqok/+w*- / rence pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2./ n8m+(kk dwvrqox 4il66 g-emuph*/ m0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through ty /:xc)t gxqsh v7c+s2wo slits 0.58 mm apart, how far apart are the second-order fringes for these:q)s hs +c yv7tx2c/xg two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light bjich.1afl)j6k + z4irw )vc, of wavelength 460 nm gives a second-order maximum at a certain location ob.+icai64,)jjr fv zchk )w1 ln the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings5u3gx kv 0oq2; ;duezj(c9 uqe 5.0 cm apart in a board. At a point 2.0 m beyond the board, at whax0zuq 2 ou3dcqv; ; keug5j(9et angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lowernz85v h6b w. 31+k-sutzjdjt u ys13br slit in Fig. 24–7 so that the two wave.3sbuzwrvujtkz-bt3+j1n y s 816dh5s 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 ligh v2h8gm+gw hq8t 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 cen8 wv8h2+h qgmgtral bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 fr, d( jy z.e5s6;sobzmm are illuminated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the sbos 65;fze ,rzds.jy( lits.    mm

  Light of wavelength 480 nm in air falls ona5onhfz1o6 2w /y+kv g 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 z+p;neq6ow.u1u ev ql4 +x.zr.60) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the scze +w .+;n6z4uoqpv r1x lu.qereen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed*v+ .ovtoky7 n of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fig. 24–14.) v7+ot* .nvkyo   %

  A light beam strikes a piece0f; y as6f/cdl:*des s 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 lig 3w5 17h4) nialwtbiekxa5gu 6ht containing 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 t*6hkgqtwn .q , 9r-eyis the full angular width of the central diffraction pe 9., e *qt6gwyqkhtrn-ak?    $^{\circ}\,$

  Monochromatic light falls on a slit tv )+o ;qvp2ptmhat 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 hb..o xw9,c kpa9 )fizfalls on a slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide isff.5*)3sndrgi xm5 goi y7ia6 illuminated by 450-nm light. What is the width of the centr ay i3xnim)5df*if5s7g 6.ogral maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on v gw+.+uyfsy.a slit. If the angle between the first yvufg ws+..y+ bright fringes on either 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.y+sm7d g:wmgi ok7g-kmhc49a( 4j+ qt30 m behind a 0.0348-mm-wide slit illumi9(+ a7k7+g 4k-dgih4 cto:sw m myjgqmnated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the firstrys.e airaey9-m ;y;1 dark bands on either side- 1eyi.ar ms;;aryy9e of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm fujbnfn5* g)i,p1 +n laalls on a single slit, it creates a central diffraction peak that is 9. jnnplfi, + )*au5bng120 cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the / 8m1sfb 6.veifww)tediffraction maximum is 4.0 cm wide on a screen 1.50 m away, wb /v mfwe1)6.siwtfe8hat will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengc 0wciaph ,l6)th $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light promciz/jcv4pda .p8 e f4n)08esduce a second-order maximum when falling on a grating whose slits are 40jfa .8pv /zpce nesdic)m84 $1.45 \times10^{-3 }\;cm$ 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 b9u 1my i,cvs4g bxa5omwf,;3grating have if the third-order occurs at an 18.0usfa3 ymbx omv5w,b; ,1i94gc$^{\circ}\,$ 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 diff( zdobq0o,ld7y oej: /raction grating is observed at a 15.5 djl/z:oq b o0,e7dy(o$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating h/dprtkgb /4qlaw3 quc1 o./ u:as $ 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 normaly,h hm(7qbj/dly 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 be seen ifj m/d.cvz(s/ec8 d *ps a grating with 6000 lines per cm is illumi * /dszcp/semc8v jd.(nated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either sul,xfjd,33;eg s xr w2ide of the central maximum when white light is sent through a diffraction grati ur3sdejxl3f,gw x 2;,ng. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavel4,-zh fzj 6/glcff9 zu:p n ax+4kp4dwengths from 410 nm to 750 nm falls on a grating with -zd69ff + w fgz4l:p4n kpx/z4acuhj,$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic lgmo4 w+;+sdebight 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 measuredf2,5wyjkc h 9pfz 9 h(zni:l/n 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;g naz;gjz.* i wavelength is most strongly reflected at the center of the outer surface when illuminatgin ;;z.zagj*ed normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dard spmh-1 xxk(2,hzn s ku5zp,odvk)5(k fringes in Example 24–8 if the glass plates are each 26.5 c,hozn1m kkh5) xz(,u5-dd sp(x sv2kpm long?    cm

  What is the smallest thickness of a soap fjp1 b py8jb.0kjp3r25kp jlpm/xmi(.*.h vsi ilm $(n\;=\;1.42)$ 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 l*bf(byfc;s*m : yk5cllow ($\lambda\;=\;570\;mm$ 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 comsdv0l 7 c6rw8)-tbwzw w3 a)eunting the dark spot at the center) are observed when68m sbw- cwew37zal)vtdr0 )w 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 sep4dx-: bl kaatf,/,cg m2kvla 8arates one end 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 observ8g kl t,c2fkal-,a4 b/x vm:aded (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two f m 1m1s(h-qk6:o*nwprg1bs0(lmd uu f c d4si:lat glass surfaces if the glass is to appear bright wun -m6*u4p c(bq:slf wdhsm( si1omr 0:1d k1ghen 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 diamondxk :p kg,zr 1./ohxxtfjw (2,zr4r6wl $(n=2.42)$ 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 2f*o:jbax,raol $(n=1.36)$ 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 liqkb l 17na70mkhuid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the rn1l kh77 mab0kefractive index of the liquid?   

  What is the wavelength of theu)m5u5x 7,basr (ubtq lb(sh( light entering an interferometer if 644 bright fringes are counted when the movable mirror moves x(uushab q(b5lt um()7sr ,b50.225 mm?    nm

  A micrometer is connected to t:ca*h5emfonpf8 (a+t he movable mirror of an interferometer. When 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 ligh:e58hnco aa m( ffpt+*t used is 589 nm.    $\mu m$

  How far must the mirror4je;g+9urg kh vl9 qj:)9iyc r $M_1$ 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 r :i;9nndq:y v2meip3meter (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 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 tmpie3 rq9dnvy;n2 :i :he interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orin 2mavk/6/v)kwd u- 4w)jtnxvented 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–gl6ipgtk0*0 v)k wg1xz iass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angledfn7bxwb92u+q8z q :z for a diamond submerged in water if the light is hitting the diamo:b+xzbwnf q 2qu7 z98dnd $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that thv m0 wl2mvay9q9;rp k : e:hzy8vsxu1:e light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequently reduced q 91mye2ky9; hxpl8rv0: v:u avws:zm by half?    $^{\circ}\,$

  At what angle should th-jyfnh9.+im p ) j5yyoe )z;iee axes of two Polaroids be placed so as to reduce the intjeoz.hyy ) p;9jmf 5ii +n-)yeensity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented4) r te9iw.fp+g4zlup at 40$^{\circ}\,$ to each other and plane-polarized light is incident on them. If only 15% of the light gets through both of them, what was the initial polarization direction of the incident light?    $^{\circ}\,$

  Two polarizers are oriented at vev iv8y ynn1e9s7-n ac./h7n38.0$^{\circ}\,$ 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 off the surface of wat ci hsu+xx 9,rl(-s0xker for light coming from beneath +ls0h, k-9 x xc(suixrthe surface? Compare to the angle for total internal reflection, 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 Polaroid sheets, each of whouu vhe8wr3t 3x q9jb/4)zj w-yse axis makes 334 ujbyure/9 )hwtz - q8wvjxa 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 7,k tfcpz) ot1,nznb+$ 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 airplanes cwtcr iil)- -a)azmh7/ an interfere with the direct signal from thmc-tha)w)-lra 7/zii e 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 sepakixy 6643;( soyl u/h-dryoe zrate sources passes through a diffraction grating with yz(/slyeo3o; y6 u4dih 6r-xk$ 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 fzg;su7ln4 a.ybxg *9 through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-ordef*7;zgxl y san.4ub9gr 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 broadcc5 a0r9y jtz*fi( zzq46k.s hqasts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A mah*f iz.tq ka5 r90ysjcz64 z(qximum 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 nat ic 4,hp/x7an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Igno/ha n,c7tp 4xiring reflections, 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 slit0stb: oy4zce m--f9zc of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series ofr/krw 75+pkk( z4dyu y parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at75pd ukrr+4zw/y ky (k an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have i2zv03 ti/v9ine) j iinf there is to be no second-order spv2tiivi )/j i3e09n nzectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spec5 +k/pm*uwsy4i ;dcs btra of white light produced by a diffraction grating always overlap. What k mdcuws5;p bs*y+/i4wavelengths overlap exactly?

  When yellow sodium light,z)gxt1lm,(cs azk+:ta 5dk 3v $\lambda\;=\;$ 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 patte0iew 9ria* f:zrn is viewed on a screen 2.5 m from the grating. The incident light beam consists of two wavelength ewf ri0*zia9:s, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 uy,dq;b veye 8-f+cc0if a minimum of 150 nm thickness of it, when laid on glass, is needed tqde uyc8b,f-eycv+0 ;o 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 normallvnreugf +2a 50m47 icjy on a thin sheet of plastic film in air. The reflected li520jucg manv7e4fr+i ght 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 a-kfqc qsso*x nk6+wo/z+td-6 n anti-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) thicknjp ;+ntu,r u kex:z2b5 sdp(f7ess for the air layer between two flat glass surfaces if the glass is to appear dark when 6407 be2nt xzurs;fjp,5dk( :up+-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted throun5l .d-hbx6a ugh a thin film layered on a flat piece of glass. Draw a d5x. an6-ulh bdiagram, 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 a (.e9yxl huzw4mdjw /1 smooth lake is polarized most strong jzuw4y h1ex(9 m./wldly?    $^{\circ}\,$

  At what angle should the axes of two Polaosd: + 2qifil8roids be placed so as to reduce the intensity of the incident uod2f+ ii q:8lsnpolarized 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 ohusd/r6l i.8 0r 38pagp kp)gkn two polarizer sheets whose transmission axes are at right angles. hk dp8 )r3srglp.k0u ga p6/i8A 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 k)-sh *s0zzoado/u; cin 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 through a slit of width 1.0 cm and is pointed at the M5mf0j cn -sav3oon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the bea a0 53smv-cfjnm when it reaches the Moon.    km

  A series of polarizers are each placed at me r x),ot2pm5ss(my; 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 ,g b(d q (dml24d+rksr$(n=1.34)$ 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 6.00u-tyof+m+ 6 t5v ppch-MHz radio waves in phase with each other. They aretu v0fy hp+-po5+6ctm 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 lighm3dvgvooaq ,23ft v4gw1ry ds 6):ik 5t containing two wavelengths, 420 nm and 650 nm, enters a silicate flint gla65s)4avoyv t13 dfkvg 3 r,qd woigm2:ss 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 flat su; i4z/o9 hhpvwz(bxj9rface 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