Does Huygens’ principle apply to sound wave mg3zk7mtn.kb ;i;5tu x9z(3pce o jl0s? To water waves? Explain.

What is the evidence that light i8 zmudlk7ssdgoqk6c2++ a 6+xs energy?

Why is light sometimes described as q2)f3v c1ljit- wq)bbrays and sometimes as waves?

We can hear sounds around corners, but we cannot si zt( gah3x;s3ee around corners; yet both sound and light are waves. Explain z3h3gsx ;tai( the difference.

If Young’s double-slit experiment were suhve9ow4,i .5sq7k9t xm4j sldxp.nf9bmerged in water, how would the fringe pattern .xfq9 hmp5xjwk. 79 l9nts, d4so 4evibe changed?

Monochromatic red light is incident on a double slit, and the interference no*r kla;+ mqhgjduw 8m8 2v2:pattern is viewed on a screeh+l g2a;wu do vjk:8r28 *mqmnn 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 the same source destructively interfere if the:0 vgnmr,2kud;l gn 8pir path lengths differ by how ;2 0ngrkl:mnd 8gpu v,much?

Why was the observation of the doubku806/o+alpytb2 .rh rel ks0le-slit interference pattern more convincing evidence fo6+ 82ulrr.bk0 ph eakys/lto0r the wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for light wa,ef rvr5tvacm w 4m+)+t qpm(-ves. Discuss the va ( m+p)vm+crrqf 54 mw-tt,esimilarities and differences.

Why doesn’t the light from the two headlights of a distant car produce axd-7 s w k:5g3of:pb;y,dwbcw n interfereb53wwfx ,op k:wc7 s-:;dbgd ynce pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is wibemzde2x3o ko-xzry 6+ ; w+9 m:4lpcovered by a red filter (700 n2;kxyz6-4+i +m m:we9dxzp l rwbooe3m) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glass, it isoyw 1x12fvs j6 not broken down into colors as it is by a prism. xfj1w1voys26 Explain.

For both converging and diverging lenses, djri*03mx sp7r3oq m4gwd )0r niscuss how the focal length for red light differs from that for violet light.ng0irm 7rj) 3*drsxqp3 m4o0w

A ray of light is refracted through three different matg3ous x0hdl01 erials (Fig. 24–55). Rank the materixsold ugh0103 als according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source through a noe)w6m05 8( vz 7y(rztmxdvjrarrow slit between two fingers. (Adjust your finge ye w7rm6zo(8xmv5r t dj(0zv)rs to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if+rt5kum 5;1 3cwuia ca the whole apparatus is immersed in (a) watekmr+ 5cutu; 5awa1c 3ir, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (almeh-8yr i. 3c) the slit width, and (b) the .8ir ym-ehc l3wavelength?

What is the difference in the interference patterns formed (a) by two slitk,q,ri- j z7kbbv/aa6vi c r/2s $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the a-z+ ,y5cf-rg/ kvq2pnyu(0o r4oytusdvantage of (a) many slits, (b) closely spaced slits?5vc/ rtfogqr2k+s 0 uy(yu,y-pn4oz -

White light strikes (a) a diffract*-e ;g0wamn tfion grating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the coaw0e- m; f*gtnlor of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 4kx0myu : tszm98(c 8dm00 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would the8xk9 s 0m:ct8m mzdu(yre be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only 9 y3sz 00tmvlb5zqz 5qfor a thin film like a soap bubble and not for a qbzm v y530q 9z0s5tlzthick piece of glass, say?

When a compact disk (nl,64 ,/:fe5fmzj rbi+ tyr bhCD) is 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 monochro64,5+r: jb/tizby,hf rfme lnmatic light was used?

Why are Newton’s rings (Fig. 24–31) clftbge-r2d(uyv )w:s7rxg4j a2o+ x9 loser together farther from the center?

Some coated lenses appear greenisxe p0.p3k )rub zldz u:0s 4/wyia:pi.h yellow when seen by reflected light. What wavelengths do you suurukxpy.:i ez:a.lpp / w) 04 03dibzsppose the coating is designed to transmit completely?

A drop of oil on a pond appears-ofji z(0 9uc8rnw fu( bright at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of refracti(nfj co8z -w i0ur9u(fon of the oil?

What does polarization dp0q5l(r p 4oj869fy 0gsyzvjtell us about the nature of light?

Explain the advantage of polarized z9c6 lwe1xeds 6)l57t c7os vlsunglasses over normal tinted sunglasses.

How can you tell if a p7mhzmw. dv lp;c; e:6xair of sunglasses is polarizing or not?

Two polarized sheets rotated at an anff*: uieq:- tnxtdr e nb8t4 iv6yq8+)gle 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?qnyn .a5sq, tm8 scb,/

If the Earth’s atmosphere were 50 times denser than it is, would sunlight sj timk5z-tohr/4 h,l2till be white, or wht5z khj,/ tl4r2m-oi ould it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces hbjv 0l90r .j9d m8-6bfljucv (f(d xcthe fifth-order fringe b-vlj c cj 99.ddrj68hm(0vxfb0ufl(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 a7i ;csmx31ykm v+he,s t 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. Suxsvz cn(ou3 /1ccessive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequenzcuo/( 31svn xcy of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a een02wm;ujnyam.5d : tnb* r-wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in t d0eewju. ma2brt- n*n:y;mn5he center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and prokcn40p qx/-pe duces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a scr0xce/ -qnp 4pkeen 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, how far as)5 k1m q k+w5a.tphvepart are the second-ord5k5+h tq1e ) spmv.akwer fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nm gm y:7fki-sri vh v)0a)ives a second-order maximum at a certain location on the screen. What wavelength k70-vyfs)): mirihva of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pat/26 *ll +xwq jir3vvgss through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the x3ig+/ q tv l26w*vrljboard, at what 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 lower slit inpss* ab3-iygnwj1bi 8 s /(f;b Fig. 24–7 so that the tn(8bb *sbwj i;sf1 a-3isgpy /wo 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 expt/ qw ,mts5b bju9+y:*i:uuy5 lm2yq teriment, 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 ofb+/u25bl 5ti tmu uyq:st, yqy mj9:*w 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 ar+isz ;n 2180i fezy//fkgjeqz; +pjure illuminated by 544 nm light. Find the distance between adjacent bright fringes on a scre zyjnj8 0zi;f/1 p +zfke;rq+sigue2 /en 5.0 m from the slits.    mm

  Light of wavelength 480 nm i ynr-lgp1a;c+h7h 1ov n 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 (n=1.60) cov jl91c3 rno()i,h: c6l hmdpqgers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. q61: )rg,(3jpcldn 9mch loih What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, doe )mca- -:oj4euypw w6bs the speed of red light (700 nm) exceed that of violet light (400 pumw6y4jw-o:-c eab) nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60.0lh;- quk(agq10$^{\circ}\,$ 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 ligm+ tp* 5:quhaght 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 is the full anguss uv7u7ed0 2glar width of the central diffraction peakuge207vus ds7?    $^{\circ}\,$

  Monochromatic light falls 9w b7 h5)jgdoa.o1v fron a slit that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength 5; qnb4 uqx h/qb co19tsn*u;n420 nm falls 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 is illuminated by d sw;,),p3ghsn6w lzn450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a swgpn, sz,w s3 h6dn);lcreen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm fallb evp(infu+od(t(cq9vv aj/ b-25 w8x,rtr1 gs on a slit. If the angle between the 5qp(airn voev,(( /tr-g9 2 wbjvb+8fcu dt1 xfirst 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 2.30 m behind ev;wa ra2dn q2 971vzwa 0.0348-mm-wide slit illumina2awzqv7 ;2 9edrnwa v1ted by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first *4 (hpgain+qsid9- c7fb2ol 2zpklj, dark bands on either side,* q(ap +24c ijnosg7lz2-iklbh9 pd f 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 single slit9 3iom9/l* po.ob.ka m fli0fw, it creates a centrabom3ifl9.i*9 owfa0l mp/ ok.l diffraction peak that is 9.20 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 diffraction maximy* m sx0ei+x+4 kq+cn0jrqxw9 um is 4.0 cm wide on a screen 1.50 m away, what +j+xq*ns cxq+x0 rik9w 4e0mywill be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength b;81 bzgr.h6 yxk 6igd$\lambda$, 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 gv6 g4 bgs+ve11jax*i falling on a grating whose slitg6+ biasxj *14v1evg gs 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 centi4t0s 8tbmja7jah 84 w b8if1qimeter does a grating have if the third-order occurs at an 8i0 jwbs4tiqj8 baafh84tm7 118.0$^{\circ}\,$ 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 light falling on a dgau.tl+ 7y u )pc69ctbiffraction grating is observed atal+. gb cc6py9u)tt 7u 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 ptb3*hpc x/9tyh e/v7-mvvh.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 normally on a )3 /x9w mt5ek/adfyink h(nh1$9700-line/cm$ 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 t0u2cug spkiu(:r+*o can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assu 02*:ug(ui+ u otscrkpme normal incidence.   

  Two (and only two) full spectral orders can be seen on either 83j2)3fui(tllhy9 to o a3qgr side of the central maximum when white light is sent through a dqoijru 9g 3 t(hll8o 32)tyaf3iffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavele) /ysr0w .3pjqib/* mzrnr1xyngths from 410 nm to 750 nm falls on a grating with r*/3rzp)jsn.rq /xbwy m01iy$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whichz 5h)wktz,f /83ejou e 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 measureq jzf(x9 56tftd 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 t. b r16wzci;pghick, what wavelength is most strongly reflected at the center of the outer surface when illuminated n1.pbr;6cz wigormally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fk .1agdc n2bgychr-bq,xd 5. i+w-+sgringes in Example 24–8 if the glass plates are each 26.5 cm long? k bshw.ccq--dg g, 5 1.ag+yr+xdin2b   cm

  What is the smallest thickness of a soap film xl sv5fmrb6+8$(n\;=\;1.42)$ 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 yellow (us mo9; y9()1g oftsex;i+kt x$\lambda\;=\;570\;mm$ 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 dark3.u/)v sfkalh Newton’s rings (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 surfacf.ha/vu)l3sk e (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically flat glass, ;mvm y0gk8 2: 7na bfx 4vxxlku6na88yas in Figkkna:6 vx gby8nl;mx4av 028fu xym87. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat gc p2e,ca9n y.rlass surfaces if the glass is to appear2, a.cncyper9 bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, q 0gy p c2q(w r0qy2yjif5agx7/3g:pfsuspected 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 alcoholizb9 e9a oxucw0j 4f1: $(n=1.36)$ 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, the diameteqrm:0kot, p eu ;a2*ynr of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index ofn m k2yo,r:a e;u*tpq0 the liquid?   

  What is the wavelength of the light entering an interferometeru lvjo cr,t-dg:0oc/ 5 if 644 bright fringes are counted when the movable mirror moves 0.225,t cj-:dlgr/o0 ocvu 5 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. When the r-1i kke3xeqf 6x-4b ja+*iu1ti sz)p micrometer is tightened down on a thin metal foil, the ne43u t)a +6xpzxirqii1*b fk-eje-s 1kt 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 mirukez 4a3jra9 m0) /flbn* :exjror $M_1$ 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 )xp ufte9o/j8+(fd*q bv)hg t. 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 tdupg9b* j8)f) ottqh f(/+vexhe gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at e 02r8d1 l6ej1poem b/trc,km65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anh83vdvp*rr 1ylu. n;(yo x* czgle for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a dij80z:51ah7 l gzpg)eqgcipl j 2,vwz; amond submerged in water if the light is hitting thez0hggz2) wjlv 57;pap1cig,8ej: zl q 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 maximum7dn)n ;i6iyce56race. At what angle should one of them be placed so that the intensity is subsequently red6 7n;ier65ced)naicyuced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids b(mv/t1sfs,tyvmf x(6 e placed so as to reduce the intensiys/(vf6s,t1 tmf( xmvty of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented k,pgn5. lg7d*dioj2 b1:* ay;-a bn*jwa iazkat 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 amxu et5-86vw .uj+haet 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 anglevlmpv mnyn/e57p 8x;( be for reflections off the surface of water for light coming from beneath the surface? Compare to8n/xple py7m 5vv;nm( 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,;x*xqa e/k :pp each of whose a ;ppxaqxe/:*kxis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength dsb -72f : f6dwa:wjuz1sf4p g$ 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 rzcefeouw4 srq5m ),) 7eflecting from mountains or airplanes can interfere with the qzwe me)ocfs ,ur75) 4direct 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 sourcsk ,j*rabcif 8mab,-t-8aw (qes passes through a diffraction grating with j8 -i f-ma,bba swkq* atcr,(8$ 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 throuls.s,ir v0 xo:gh 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 thxrs0li.o s ,:ve 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 idex+-e4yn ltv-ik/o;b t rr ql/+ntical antennae at the same elevation but separated by an 8.0-m horizon et+nbxolkrlv-/ /;t 4q+r-iytal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back from an outside doorway d/e uzfi7 tqly7- 6h2:w9o eve0.88 m wide, and blows a whistle of frequ7t2lozv dq e/he6ywfe9:7 -u iency 750 Hz. Ignoring 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 slit of width D at a 30.q-ublt xzol0zy 9 (a0$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain bee21; spwvs5ve ltle have a series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, thv21l5;pswv ese 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 nobchv)5tkom8mmv e :p6p :di89 second-order spectrum 6ihp 89:bm)5v tdvk cpe8omm: for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white e.5yhb72 rk/q f2cuvd7lu.ikt93gl zlight produced by a diffraction grating always overlap. What wavelengths overlap exactl lhqek3y2/.rdg9t.vu5fk72 cu iz 7lby?

  When yellow sodium li8juj5 f0fui.6 xntd,wght, $\lambda\;=\;$ 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 2-*.zv-h vc mermfk :ml+wig* is viewed on a screen 2.5 m from the grating. The incident light beam consw.k2i hf- re zl*mm+:gvcvm*- ists 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 a38m66cz oevts minimum of 150 nm thickness of it, when laidstcz38vo6 me 6 on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelengthi-imy7tmh* qs k8iywipk *059 is incident normally on a thin sheet of plastic film imik0 p*mh798k iw*s qiy-5tyin 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 fybspk2 8 xi4cs+ *omk9/*gdpaor an 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) thickness for the air layer betwfbli-/ 0g: z:k)jw-0eoegr raeen two flat glass surfaces if the glass is to appear dark when 640-nm light is incident normally?e) :zk i0e-0-/ljgrw:rfo agb    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted thro (m64j0vghd3 ry)dnskugh a thin film layered on a flat piece of glass. Draw a diagram, similar to rjy)0 4kv3 dhsmg(6 dnFig. 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 theq +ddyv 3nq.-;.txs wv horizon is the Sun when light reflecting off a smooth lake is po qd- vvnw.d3s+qx.;ytlarized most strongly?    $^{\circ}\,$

  At what angle should the axes oft95h;3 mcwlxpuj j. *ojb5q 5f two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in h3jx9 t*5bhfjcou5l 5;qw.mj palf) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on t:- je,9lraunpyu +/ grwo polarizer sheets whose transmission axes are at right angles. A third polarizer is placed betweenrug,e:lr puj /a+y9n- 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 in succession with their axe6vair6,a mv )is 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 point8y+g 8nm wl6uyrng4- msi0z1ted at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wav8zsunwl- 6ym r84mggy +0ni1 telength 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 placed at a 10knma3 sqsl n+,*,jpl o3yk3m)$^{\circ}\,$ 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 i:a : dcyrl2s+ m 2ap(:rsf2)3zaiogs $(n=1.34)$ 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 radio1qpo:ufo0zuw5 cf/p6 waves in phase with each other. They are located atq:p u165opu0c wffzo / 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 coqsu*3 qb5e kb0k 9+rlbntaining two wavelengths, 420 nm and 650 nm, enters a silicau035l be9bsrk*qbk+q te 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 e,rb st4gg/r4 2aicl, has one flat surface and one with $R\;=\;18.4\,cm$ It is used to view an object, located 66.0 cm away from the lens, which is a mixture of red and yellow. The index of refraction of the Lucite is 1.5106 for red light and 1.5226 for yellow light. What are the locations of the red and yellow images formed by the lens? [Hint: See Section 23–10.]
$d_{i-red}$    cm
$d_{i-yellow}$    cm