Does Huygens’ principle appls0.98qbr5b brhx2w kyy to sound waves? To water waves? Explain.

What is the evidence that light is energy dc45ncxxez3 ib6 ;9hc?

Why is light sometimes described as raysh5 heh9)1bswk2 mbj:j(rdt 2m and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet bo91ix9;.pngrbnijds 38nzs y . th sound and li8;zx.ns9.i sdr3njnbp 9i y1gght are waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, hbi/t7fvti4 )wow would the fringe pattern be)/ iitf b7tv4w changed?

Monochromatic red light is incidodxh4hcne 5om*; k u+8ent on a double slit, and the interference pattern is viewed on a screen some distance away. m 5cuodehn4*ok8;hx+ 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 their patw0 xfkg e 1 7q3:tljpe+ut:j6wh lengtxj1kpt u 0t:w7gfqe3+wl ej6:hs differ by how much?

Why was the observation of the double-slit interference pattern more ;6kopo3kjk,i( gt-m. p1qp3qjz s0tu convincing evidence for the ,q-( k;jq.jik0 gtkp1mpotz p63s u3 owave theory of light than the observation of diffraction?

Compare a double-slia/q: ;btwljio, o .ae6t experiment for sound waves to that for light waves. Discuss the similarities and differencesiqeal :,a/ jobtw6o .;.

Why doesn’t the light from the two headlights of a distant car p .t 6c(2u(yrz/) *emefe ebajproduce an interference pattern?f.((*t c/m6p eezer2e) jayub

Suppose white light falls on the two slits of Fig. 24–7, but one slit is:-5u6xo3fwcwgv dgnc -anp:/ covered by a red filter (700 nm) and the other by a blue fi 3:n/gx 6:an5upf--gd wccwovlter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of+m7es-fa.f:4s; )iild h yhpx window glass, it is not broken down into colors as it is by a prism. fm7: p xea4ihsfsyi)d -l.+;hExplain.

For both converging abag,a;-e er8and diverging lenses, discuss how the focal length for red light differs from that forr- ab8,ea ;age violet light.

A ray of light is refracted through three diffe7px6oth wsd s7cv 1)f4rent materials (Fig. 24–55). Rank the materials according to their index of refractios ohd1csxv 4 f67)7ptwn, least to greatest.

Hold one hand close to your eye and gy ygvm3w z33w:a/mt.focus on a distant light source through a narrow slit between two fingers. (Adjust your finger. 3mmww3:vzgy/tgy 3as to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if p +1d wu7 otui;aes,5bthe whole apparatus is immerse5ui,;dosa te uw+b 7p1d in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of inc.n, d+pup er6ereasing (a) the slit +u np e,ep6.rdwidth, and (b) the wavelength?

What is the difference in the interference patterns formed (kk55 +vx qq8hxa) by two 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 slits,;eiw;vdumu130b k .vm (b) closely spaced slitme1ud;30bw umiv; v.ks?

White light strikes (a) a diffraction grating, and (b)p7u s8v lufz39 a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow in each csz8lp f9 7v3uuase? Explain.

For light consisting om2k 6cla:z i6cbms0jc9a2-hyl : nyt;f wavelengths between 400 nm and 700 nm, incident normally on a diffraction grating, for what ojlm2 cn 6;0i kb2a:yms9ctc :hal6zy -rders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference frie,8neb 93)i drce)hc bnges noticeable only for a thin film like a soap bubble and not for a thick piece of glass, say ri3de8b)ce 9enb,c )h?

When a compact disk (CD) is held at an angle in white light+/ nmxbchl4z (, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monx+ l(4 nmz/hcbochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from thexj /(mdnl:y m-(kqzpsyym.w1 :zsy4 m0++c nv center?

Some coated lenses appear greenish yell w/3am+:(svsidaz+i8,jo x0y 8 z njbqow when seen by reflected light. What wavelengths do you suppose the coating is designed to transmit comi vq+a,zwjo8+:sjdy 0 ai3m8bn( /zs xpletely?

A drop of oil on a pond appears bright at its edges, where its thickness is much9zvyx4 yn oyu 1*:js2jm,vzdu /lq,.o less than the wavelengths of visible light. What can you say about the index of refractionuo*, 4. xjo us vyzql/:2,1m9jnvyzd y of the oil?

What does polarization tell us about the nature of light? - co*j -)4ma;xzthvhc

Explain the advantage of polarized sunglasses over normal tinted sun w nt+ xhyupwj4z*t+2,glasses.

How can you tell if a pair of sunglasses is polarizing or vik ok+tw;:,s : -ofx55xcunv not?

Two polarized sheets rotated tvi bky, 1hqwo9+y 5,w4 2yyprjiw27fat 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 shtp. ) cs5av3 ,* pki*zox*hjqky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 ti,szo8pivu h, 9mes denser than it is, would sunlight still be white, or w,9 hpv8so,i zuould it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart prol d-x9f jx+5* zxkhu ,gar*xo.duces the fifth-order fringe z,au*o g f-xrj.lk5+xdx*h9x 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 obc5wt.( u5 vsq1(kl nlijxpa++g,0axgserved 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. Successivebu7icp62r eo, fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Dp ,e27ou6b rcietermine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nm, falls on0mkb dg : kz5f;+p7dzb two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of the patk:f0p5gdkzm d7 +bz;b tern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls ox -cis4s e:sbe3hfuu-oeu 4o5+ 0//rtyh:o fqn two slits and produces an interference pattern in which the fourth-order fringe is uree oi u5h+s: fbshyc/o:eqx-4u 3tfo4-/s038 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 tuc+:0600 kzwehtgvm qhrough two slits 0.58 mm apart, how far apart are the second-order fring+0 wgh:qm u6e0ct0 vzkes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment,ji 3 qm0q0p)rx it is found that blue light of wavelength 460 nm gives aixjq3 m0)rp 0q 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 2.5 cm. mdft*7rmw 7b zl;fde/,j1tv 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-throulfr;f/71 j,vdtbd wm m.z*e7tgh” direction would there be little or no wave action?

Suppose a thin piece of glass is placed 45cc8d(hlurikj wgfh9p64 a 5vl ;lt;in front of the lower slit in Fig. 24–7 u;i9l8( d cphkctv ;hj5lwr 5af g44l6so that the two waves enter the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the w yh7k gp9l4u;.;nsomthird-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located? gk;; yhw9slp4 m7u.on    mm

  Two narrow slits separatez67(/yh riiu+ p7ttx rd by 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fr/ypt7 z6x+rtriu(hi7 inges on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on twou:n2ll 3 +myez slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a doum7+ak6s obtk7aj +zp(ble-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plasticjpbk(ot7 6 m+ akzas7+?    nm

  By what percent, approximatelf(b eo ui*:ix6y, does the speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glasu(fxo e6 ib*i:s? (See Fig. 24–14.)    %

  A light beam strikes a piec)cwvey7mt1 r2e of glass at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light con,jg:q*p cyxp 8qsj:4s taining 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, whascou lu0m 05b 7mq8s.wt is the full angular width of the central diffm78cslsq0wmu .0b o 5uraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that is *iek kr-jx7i5hxb5 .os6gm6b $ 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 fdy4-chtwt j g j ie;7/yq ,gv7l61f7gnalls 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 450-nm light. Whk7qub 5pp 0cez czo /cdh810- 4j26h8akob fheat is the width of the central maximum (in cm) in the diffra8cfu hdj 1a7602ohe/50zqcb-4ckebko z8ph p ction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a.d0o,bo7m+ yk8c.vqnc o tb.v9 e3 amj slit. If the angle between the first bright o ae9m. qb.+d8ocvvoc n.b jmk,7yt30fringes 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 a 0.03 o;3 znohww90u48-mm-whw0 w9onz;3 uoide slit illuminated by 589-nm light?    cm

  When blue light of wave.7rtdjvo:d p 2length 440 nm falls on a single slit, the first dark bands on either side of cented prt2d7oj :v.r 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 slit, it creatm3-e d xl8oq:8b b-f1ov+q.f x5jz*b*rgfoywes a central diffraction peak that is 9.20 cm wide on abybbz81o--fgoo83q* mx+d *v5 j:qf.lewrxf screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that thrfqgo m;92hp 9i +oo/xe diffraction maximum is 4.0 cm wide on a screen gphx foo;moq2+9ir /91.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength2kx; 2jdrqquo2zoch- f3;kvx b* 5/t m $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 5607r ab1wsu6ba ;-nm light produce a second-order maximum when falling on a grating whose slits are as1bu; a rw6b7$1.45 \times10^{-3 }\;cm$ 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 cey1ii( z0njpk 9ntimeter does a grating have if the third-order occurs at any 0nkj9izi(p1 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-nm light (k5fo)o;pd8hr en j( ld7xt(h falling on a diffraction grating is observed(p d5 t((xnokh 7hr;)8ljodfe at 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 *d99xz/ wmg kg g ln3tpd/28t6sati7bhas $ 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 ozfi-r-xr )bh/ 6ybbky /(bz.hn 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 if a grati 0xgg3jyoekr3w;g;4hg8 lu (o ng with 6000 lines per cm is illuminated with 633-nm laser (0;3xgo wkg y8he 34ug;lgo jrlight? Assume normal incidence.   

  Two (and only two) full spectral ordengc8xk19 wb 7 iw.s/phrs can be seen on either side of the central maximum when white light is sent through xp89ng1ih sb/ w.ckw 7a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 7 3;v,8 haqwfuq )7csqx50 nm falls on a grating with,a xv;8h sq3)wcq7fqu $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monoch.6unt,h4yi e+n ry qqox5i21 vromatic 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 linep1k2m7 nbca31 uko c s7195 nzfmy3jbys are measured by a $9500-line/cm$ spectroscope at angles, on each side of center, of +26$^{\circ}\,$ 38$^\prime$,+41$^{\circ}\,$ 08$^\prime$ and -26$^{\circ}\,$48$^\prime$,-41$^{\circ}\,$ 19$^\prime$. What are the wavelengths?
$\lambda_{26.72^{\circ}}\;=\;$    nm
$\lambda_{41.23^{\circ}}\;=\;$    nm

  If a soap bubble is 120 n*o9 rswq6 uw1km thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by white lighs*w1 q9 6wkorut? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the gln6 rm7oll* lqcco4xaz7p,.w/ ass plates are each 26.5 wca7r6/oc,llp*4q. nol7 xm z cm long?    cm

  What is the smallest thickness of a soap(d +zjgfr +3dtefu +q. 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 yello k r/1v y c*xvpt27sfarky4vn f.b*:*nw ($\lambda\;=\;570\;mm$ 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 the dark spot at t8;8olgrxmvv + 1(eey9ck pp x-he center) are observed when 550-nm light falls normally on a planoco9-8y ( +;l8oxev1cxvpem kgpr nvex 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 )j qfb+f-om; 9elfxi76cg 6xrof two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, ;ol6 eib ffrqf9j6+m- g x7xc)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 glass surfaces if s*gmjlz.s/6ya(8se e the glass is to appear bright when 450-nm light is incident normally? *g 6aszel j(/sye8s m.   nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a st.wn6 tur,0 .xusd47y5 gmqzb+:npq-v0le i fm olen 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 alcohxltjizw tli-6: f 5/9vol $(n=1.36)$ 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 cd;jd+glwdm :kg w,m: n3:9 8-9rd0a urybsmg(Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refrrr3d8::mjlud,wg : dn9+wm ky a0m9csgb- gd ;active index of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 brigh piyzp2oxy g9yk2 +w(9 )tbondf 4z)*lt fringes are counted when 2z nyg)+ptxyzbw 49l2*f (9 opikyo)dthe movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mi(f(9 pby bzla+rror 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. Whlzafp +yb(9b (at is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror zgb58n7eq m5v $M_1$ 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 (Figeqa*bbt7ghq ,2c9rvo10hsn* . 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*sb*bn aqhq1hc2etv,7r 9o g 0 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 9+m41pxlh) g.f1 yif e oops5a65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–gmo9sx 2:+ pjnrlass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is hittt9/b*u3i: dxug/zs2bvb7wm qing s xu/ub*23:/g bwzmbtdv7iq9 the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing th6)ums f; yj/idrough them is a maximum. At what angle should one of them be placed so that the intensity is subsequently reduce6sd yf/m)ui;jd by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plac6qurcl2lu00ee em(wb)+5zr/s *b bnfed so as to reduce the intensity of the inubrmzle0 5u+ w)lb6 qf sr(/2be*n c0ecident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented3j-w . mj yctyx3pqq61 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 3/pg 5 .n*agrmez/kan;8.0$^{\circ}\,$ 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 surfj sm xpnbd+.3 i 0i7jsmia):m 6hnb3e+ace of water for light coming from beneath the surface? Compare to the angle for +6mjjex):7ini3banmibmphd+s 0 .s3 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 wh( 0h+d l(cowti1w ff3mose axw1itmdh fl3 ( wo(+0cfis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength pnd s5g(4jr-hwbzq0; 5kzq:h$ 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 mountaiz m5-7xdvwy3o x0x h(vns or airplanes can interfere with the direct signal from the sv03o-(w7vzx m xxd5yhtation.
(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 n36 7iepmsi y*np 9xchwj667w passes through a diffraction grating with ew66 * 6m hwyspcxn79iipn37j $ 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 passo rkp1u)*l;hees through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown waveleng*rkhu e;1lp )oth produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at da (m2fmx h0lqa9 ,u)no(m1ay102.1 MHz broadcasts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its mid9m1( amo0a , u)nd2f lmah(xyqpoint 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 wel,c*,* fovdn2q91bl,ga/l, yugv q7eh u ieh3wl back from an outside doorway 0.88 m wide, and blows a whistle of frequency 75,l,dgfvni13euq *ec ,hahwq92/, o* gub yv7l0 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 a7v e9z)uio. kbt a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lin4t* fum mo8kq 3).4mdktp4pmbes across them. When normalld4m44.kt3kpmoq t *)uf p m8bmy incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per c+hi xdncv.i)4 v .sm2kentimeter must a grating have if there is to be no second-order.i+vh x 4c nids2m.kv) spectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light prodz8iu 9xl6fd: n0x3+lnu)rygouced by a diffraction grating always overlap. What wavelengths ovgu 6n93x8:fzxil u)nldr0yo +erlap exactly?

  When yellow sodium light,5. y/au a3gfcjn45ggr $\lambda\;=\;$ 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 wi u qd.pz w15nv;a5vv8eth and the pattern is viewed on a screen 2.5 m from the gratingq 8 vuz. d5;w51vpeanv. 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 qsx0i )jpd 0xw ze49n;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 have aqxs0 9d40zjpi xe w;n) choice for an answer?

  Monochromatic light of variable wavelength is incident norman)l9k: uggc( elly on a thin sheet of plastic film in air. The ref gg e:ncluk(9)lected 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 coatiz(uy +6ktc 8hing $(n=1.38)$ 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 between two flat gl1 39kjl mmxdp8nf; )zfas 3kzjmm; )fdfl98 x1pns surfaces 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 a t rpk70 w2qesw81iz r-lu,mqu9zjd +5 ihin film layered on a flat piece 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 el z rsd,jz+iqmr 5q9uwp82-w7k 01uisize of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun 0 u;;5gvzez3 jw;ktyfwhen light reflecting off a smooth lake is polarized most stro5u3 ;j;wfgv ezztky;0ngly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reducii0 e63s 8hf, u,swoval:r-dae the intensity of the incid v3a,wa0i rh:u -l esd6f,s8oient 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 sheetx y3n9 fqx93ixs whose transmission axes are at ri3x3fqxy 99 xnight angles. A 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 in succession with theiqz fa849 o fwkq e2p4om2vw;7ir 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 m y8p rcvi.f *bfmz+5/ f3r*oda slit of 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 He-Ne laser). Estimate the width of the beam when i*r8fz+f 5fpo rb m*.i3cm dyv/t reaches the Moon.    km

  A series of polarizers ak5ch2 xt-ou pn;is)n 0re 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 /kibn6ya w(eto6t dn (2.n-xo$(n=1.34)$ 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 ra1ueco8t w:o o70yft 5ldio waves in phase with each other. They are located at points te81ootl5 7fyw:u o0c$S_1$ 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 lighy609ju yi2 5w/dg cecit containing two wavelengths, 420 nm and 650 nm, enters a sily 2cwiy uc g96e/jd05iicate 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 onqbkfj /1w,n oz,i 0k7me 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