Does Huygens’ principle apply to sound waves?zz 57tednz0r ( To water waves? Explain.

What is the evidence that light is en qvv6g2+s p4pmwzt;bp;ijo 0; ergy?

Why is light sometimes described as rays and sometimes as xreg56f f)2k; wnx hsaoqu.1*waves?

We can hear sounds around corners, but we cannot see around rol66yas( m*mcorners; yet both sound and rao(y *mm6 s6llight are waves. Explain the difference.

If Young’s double-slit experiment were submergedidbpai;p ,w1/ )ew cpb/r 2ys)s:g3uk in water, how would the fringe pattern be cb;wyek )ci/a3ib/p1d:2r usg,ps)wp hanged?

Monochromatic red light is incident t -;rxjgyoda3 *g ;9d6ganl6x on a double slit, and the interference pattern is viewed on a screen some distance away. Explai d6g;*tna rxo9y;3ljdg -gx6 an 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 path len4jm6 ; mn1p zj5 h9qi1wmoot5ygths di; m6zom1nyi 5womq419hj5tpj ffer by how much?

Why was the observationrzjh pao)y-zfc y367 3 of the double-slit interference pattern more convincing evidence for the wave theory of light than the obz-ja )y33 rfo6hp7 yzcservation of diffraction?

Compare a double-slili3q 2smlj.,zwd8- gmt experiment for sound waves to that for light waves. Discuss thz8w3l-ql sd.mm,2 jgi e similarities and differences.

Why doesn’t the light from the two headlights of a distant car produce an i**dh:0 ;t tz,lb+eam l5 a*ut*r;p j:zri sdwjnterference pattern?t*dz5uj: i , htm0t lrd*e*jzp b+sa;*w:;lar

Suppose white light falls on the two sly l86ucp1v3jmf5odt2:4vt ;drooq1cits of Fig. 24–7, but one slit is covered by a red fi:v pl1j tqm1v8cr3cfd y2 o4 65otd;uolter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glass, it is not 8 39nr2 l 2o in((hjdrqh;yrehbroken d22o(l ei9r3yq8;rrh( nhhn jdown into colors as it is by a prism. Explain.

For both converging and diverg(wqnl g5 udu7c+ :*hogy5h 7fqing lenses, discuss how the focal length for red light differs from that for wu (ud go+7hn*lg hcq7yf55 q:violet light.

A ray of light is refracted through three different materials (l cg9boalr 7t/ fk.*. ocwyf59Fig. 24–55). Rank the materials according to their index of refraction, least to g/y.9 f *at wbk5clg 9fr.olo7createst.

Hold one hand close to your eye and focus on a distant light source throug p 5 wr9sjtp y;mx;-tml3d4g5gh a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.)pj5 4;g mw tgp9rl -ms;5y3xtd Describe the pattern that you see.

What happens to the diffraction pattern of a sin(x,6pz+xik b 5vmz; dugle slit if the whole apparatus is immersed in (a) waterz;kpudx5bmv +6(x,z i , (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effekpdctfmu28j qd1q w,-2b2h r/ct of increasing (a) the slit width, and (b) the waveleng,- bmp2h1 2rwkjddqt/qcu82f th?

What is the difference in the interfe w a1l hy vzs(x ukuy474g1g78yx+jfj8rence patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (a) many si(hz1 kv ,n: 1a(wrsqylits, (b) closely spaced s:(, 1 vnrzhik(s1w yqalits?

White light strikes (a) a diffraction grating, a8czm+9kd 8isut*6li4* grwva nd (b) 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 case? Explw9ri6cl8ugt4*a zd* 8ik m+svain.

For light consisting of wavelengths between 400 nm and 700 nm, inc/c2g 1obrp*p dident normally on a diffraction grating, for what orders (if any) p dbc/r2g1*opwould 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 like1:pnosziyz 4 g4+e+tmw(lu9b a soap bubble and not for a ygzm+piwszun e:9b14(4 l +tothick piece of glass, say?

When a compact disk (C,0rz *yn hj. udjth,dxn5 +b1wD) is held at an angle in white light, the reflected light is a full spectrum (Fiyj, d 5 b.u*thd,xr+z0jnw 1nhg. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings :kmup )forv(ugi;0-q (Fig. 24–31) closer together farther from the center?

Some coated lenses appear greenish yellow when + /g020y4,ywsx bd8gl geu ffeseen by reflected light. What wavelengths do you suppose tef0b,sug yyf /82le0g gw+xd4he coating is designed to transmit completely?

A drop of oil on a pond appears bright at its b4 dw;g0qm6v kedges, where its thickness is much less than the wavelengths of visi0mk g; dvb6q4wble light. What can you say about the index of refraction of the oil?

What does polarization tell us about the nature 55w*dq hnip(*n xpao*of light?

Explain the advantage of polarized sunglasses over normatsn:o sa sit,;(9qa+vl tinted sunglasses.

How can you tell if a pair of sunglasses is d8 vmwv903gf2/ -gwbhbq2iiepolarizing or not?

Two polarized sheets rotated at an angle of 90qxsdq-sn ,a/j6t k72r 0mjbm8$^{\circ}\,$ 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 atmosphedof 7rag 95qr;onf5c0 re?

If the Earth’s atmosphere were 50 til+qe( gqo 7xq411qo qri( +/ckbfbc1u mes denser than it is, would sunlight still be white, or would itxuqbb q(kfcqqr7/4 (geio1+lc1 o1+q be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fif5t(jn:t0gtxg)zzi b/ th-order fringe at z5(jz g :xt0/igt)tbn 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 at an,mmlw9( j9 rsu 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. Successivw2u ep9yf+)gdx) 4s zle fringes on a screen 5.00 m away are 6.5 cm apart near the center of the ppy9 l4dzg 2 uewf)sx+)attern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne lo71 o 66wsdqhnaser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringhds6wono7 q1 6es in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on 0sc4 gpa60wwckj)hmgf;) o -f two slits and produces an interference pattern in which the fourth-order fringe is 38 m c6kmo)gj fw0-a)ch;4 gp0fw sm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, how fadh :/ xs7qhy*g(/ceq;e(oyxkqf)s 6 hr apart are thq cks//xd(h *hx 6(:g q; fyhsyo7e)qee second-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue l 9ysggg t3;l4jight of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible lig3t4sg9l ;j gyght would have a minimum at the same location?    nm

Water waves having paralleqx ) w3yad0oo+5alzq6 9q :cevl crests 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “straight-through” direction woul) a0y5d:xcw6qevo+ 9zaq3 qol d there be little or no wave action?

Suppose a thin piece of glass is placed in front 2yyk*.mt;) f wrp4 w+f7 dwlmtof the lower slit in Fig. 24–7 so that the twom ;tklp.y)y 7w2ff+wr* w dt4m 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 light of wavelength 50 hxylh4 jw 6g9v;/6xz+oqhplu be09s+*q5 o zq0 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 t90ow9qhsv/ h jgbhq pz ;zoy4x*ulq+x le56 +6he second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are ilyya7qq: *ikh 3c6pz n,luminated by 544 nm light. Find the distance naihcz,6*y 3 7qk: pyqbetween adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nxct vm-s6or)lni) y izw;q 0sl)s+-u .m 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 (n=1.60) covers one slit of a d 3kvmk fb o969u.y+nhcouble-slit apparatus illuminated by 640-nm light. The center point on the+9.c no6bym3hku9vkf screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (3 (k)f,msfg og700 nm) exceed that of violet light (400 nm) in silicate fling)ofs3,fg k(mt glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of gls.;ge(u4 lqnbi(lah 8ass 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 co-,s8rvf3g3 9xk y jferb is:x9ntaining 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 nrr,vg2rb uh-0g w+kd6h* l.o 0.0440 mm wide, what is the full angular width of the central diffractionw*robkhl.vng u+,d-0r6 ghr2 peak?    $^{\circ}\,$

  Monochromatic light falls on a slit thik.-3e4qkehw ,ego /g at 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 that is l4 ghbm o.qk-*-6i.cl3lx ej y$ 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 v1w x6qq s*xvv2v0/xdy 52idi450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a screen 5.0 m away? xx wvi1/i ys*v0 d252 vdvqqx6   cm

  Monochromatic light of wavelength 653 nm falls on a)bu ok w9e+vm+ slit. If the angle between the fiv+) u+meob9 wkrst bright fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffrank8 .asm8 il40nq gi5jction peak on a screen 2.30 m behind a 0.0348-mm-wide sl m5i ngj 8n0l.iqk84sait illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first 1fyaodl,i 4 h ( 3fh43nxbp4btdark bands on either side of center are separated by phxyo,3( db lf134bnt4 iah4f55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavel7jqyckpdf8 vxh, b(pns t/6v; x85/nlength 415 nm falls on a single slit, it creates a centralj q ,xtnnvdppx(y /;b6/c sfvl8h78 5k 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 maximum is 4.0 cm wchhq.vu8m* o-s vulxp koj9012kn90 r ide on a screen 1.50 m away, what will be the 8u lrp*ov hk099sx.q c njv2-o1h0ukm width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt l nxrc*twr)2i)8hb.dh $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a secon96 / ast8qee mon,ux/9yp1niwd-order maximum when falling on a gratino pen9n9,et x1 m/wyq6 8is/aug 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 pm20a14ba41wn da kd,ini ;tgdoes a grating have if the third-order occurs at an 18.pin 0d4 d na;12ia41ab ,mgtkw0$^{\circ}\,$ 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 58l +iaq 5; e9;ax,im7 vn ,xnp0-kjjnpt9-nm light falling on a diffraction grating is observed at a 9 np-x aj0e7nqv;imn+ktp, l; a x,ij515.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating++eme4 (y3uz*sn* ozkjc zo. g 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 normally on a lk:f yp *6a8oa*dz-le $9700-line/cm$ 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 grating with 6000 lix5v4z9 t(hehc nes per cm is xch59( ze4thvilluminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can:ns: a ht+/nwt be seen on either side of the central s/ tnhatnw+::maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths 2gq 4pbaw.z/ tfrom 410 nm to 750 nm falls on a grating with /wag.2 4t qpbz$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light of a known wavelength qvcy f(2k.uc8 ;v -bvb$\lambda\;=\;6.328\times10^{-7 }\;m$ 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 spectr5.8dzo zb)o pqz lwa,,um lines 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 nm thick, wuue(ixf v, s(-hat wavelength is most strongly reflected at the center of the outer surface when illuminated normally(v- xueu(, fsi by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24– lxkc;fpk5q8+8 if the glass plates are each 26.5 cm ;x5 8cfkpq+ lklong?    cm

  What is the smallest thickness of a soawtu +f9qd8zw +p 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 yz(-z3 hy/fi mznvv/ f)ellow ($\lambda\;=\;570\;mm$ 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 rinp.jd o:-.mhrjw* +y lkgs (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 surface (Figp- mh:.l+.jrjko *d yw. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separate)d7,k7zn1rfknnx iq ,n0b0 y js one end of two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nmr 7q,k1n7 nnbf,j 00)dynkx iz 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 qp8w: (e ln),znz+hyc between two flat glass surfaces if the glassz:hp8( w cqn,)lyez+n is to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of bei l;mq2lpy c.z8ng 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 alcoh3q9ua63ib . pptqxw juuf3e8ee6j3a8ol $(n=1.36)$ 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 d*efu il (.qzrk53ehfdj840 qa liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the l4ff l ehej.id3*0dz8 q5rkuq (iquid?   

  What is the wavelength of the light e)my2 d89x*eysqix2gzo+i tb 5ntering an interferometer if 644 bright fringes are counted when the movable mirror moves 0.225 )5itz im8 +22sbeq g9xdoyyx* mm?    nm

  A micrometer is connected to the fgou+e+v ;yk-*zws j 2m-xa 4lmovable 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 thicknes+u4em xf2*-j+okywg z lvas;-s of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirj*ghx b 7+vjs-ror $M_1$ 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. 24–59) passes througx 0g5er+gf/lj, u au*kh 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 referee/,0r*a5jlkg+ xug funce line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 65t2wi5sf:qm 4j$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s an+5ysriy mvd65 ()c rzms)/o :jauf3ycgle for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond sub t:h*dgs/u om ei9 c*ed(:.dp eaf4hfqgc*h-0merged in water if the light is hitting the diamondeae*f4 s gh: (phto d*-hmig:ducq f0* dc./e9 $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing thr,e202qp3mav iqij h 7oough them is a maximum. At what angle should one of them be placed so that the intensity is subsequentlmq j7,hpio2ae 3i0q2vy reduced by half?    $^{\circ}\,$

  At what angle should tsrn/vd 0ygsz+ )j75m nhe axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized s+/n5zv7 nyr0gj ds)mlight to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented 6hy*yd4i h/qrqv i:*tat 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 xl1 -s95cenla at 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 reflectioniika p 0a8yql6)c,m2h rm7r)a ls1 /gns off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and /ah0il) py1r8gqm2 ,km 7n)slaaric 6 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 whose 6 rwj,z ;y31woz8jzj.ydav:gz x+ 8snaxis makes a 4x 6s1 z8 jr j+vgy;yzow.:j83wand,zz 5$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength qf +xjfb3b7 g0$ 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 wrkefra1n )33b aves reflecting from mountains or airplanes can interfere with the direct signar f)k3 nra1eb3l from the station.
(a) What kind of interference will occur when 75-MHz television signals arrive at a receiver directly from a distant station, and are reflected from a nearby airplane 118 m directly above the receiver? Assume $\frac{1}{2}\;\lambda$ change in phase of the signal upon reflection.  ----待选择----constructivedestructive 
(b) What kind of interference will occur if the plane is 22 m closer to the receiver?  ----待选择----constructivedestructive 

  Red light from three separate sources passes through a diffra93owo/;+l) /wqg yj5x vl movyction grating with g oyow3 +l yv wj/lm9)v5xq/;o$ 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 through two narrow slits 0.60 mm qkk+bny82w ;ien*, hj*/ mthaapart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer t+neqw 2tk kjyn*8m*a/;ihbh , o the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two identi+ b(y+x,6vufl7sabu) 5ezwil cal antennae at ey)ubv (a ,i5 +wbllfsz 7+ux6the 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 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 ouk*teksm61 b 7etside 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 whis1s6 e*mtbkke7 tle 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 3s+k y +le q8n2g-pn9ciaf8n+g0$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across thedwq,f t 5n *khu0onnkz645 fb)m. When normally incid)0fbd z5 w6ot *5qu4nnkkhf,nent 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 centimeter must a grating have if there is to be no seyi4la /rwz+anp7bhek*, +.nfz9qk ,i cond-order spectrum for any7*lib,+k apz ,ekw4n/rzaif9hn. y q + visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of k7/u+z a q s y1q0w,dk0zd)uozwhite light produced by a diffraction grating always dyqdk,zus au) w17+00/qk zzooverlap. What wavelengths overlap exactly?

  When yellow sodium lighg r ntp,jzh9*262zvazt, $\lambda\;=\;$ 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 diffrsjuoc 0pw29vrw/b 6lx3 tp,3gaction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consio,0bg3uc 9p x/3vsw 6t2 pjrwlsts 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 r5avru b2 3.+rqi8ezd refraction of a clear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero whd2 r85erbqv+3ui.ar zen light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident normally kmn 4vj9o(qxw-, mq giqx)/i:t; n+xgon a thin sheet of pqng9- j( nx:qiwxogm x4)ivt k,+ qm;/lastic 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 thzusibby )eykj,w,f 4e9+( f, iickness needed for 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 betweench )m)xh*7va5 v8t4vo ygq -jb two flat glass surfaces if the glass is to appear dark when 640-hgvo4 )cb )xvjh7m*58v q -ytanm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted througqf x o5,2)c56/ r 3gkegflaawzh a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and axfcr /al5o)q 5w kze3,g g6f2describe 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 gt i ;gz hn:fb6xcs85-smooth lake is polarized most stronglsz8x :c;g 5g-b6 nfihty?    $^{\circ}\,$

  At what angle should the ixrp+ yq,+t.d axes of two Polaroids be placed so as to reduce the intensity of the incident ur+pt, d+i y.qxnpolarized 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 trans-pk4/;kz3p4c jm+qo doh( jye mission axes are at rq4c(kzjo+p3h/4 dje ;mpy ko-ight 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 witq -rap hnhfm1dm *+h/ r0f.ha3h 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 cma(jgc;k s2a v)dvz(wvj/(5v c and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume t (v2cg kcwj;v5 j()v(va z/dsahe laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each pl)x3 cwmf dcqbs m*8+(bsu k2b/aced 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 03ms ultwynn fh;z3ogs/+)reo)h-w5hps2 t0 $(n=1.34)$ 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 phasea(xt* rx7xyzq;1okn(ssb *8y with each other. They are located at pointzy8x( *tx 7kxasr(b y*o qn1s;s $S_1$ and $S_2$, separated by a distance $d\;=\;175m$, Fig. 24–61. What are the first three points on the y axis where there will be destructive interference? (Destructive interference in this case means that a radio receiver placed at that point would pick up no signal).    m    m    m

  A parallel beam of light containing two wavelengths, 420 nm and 6k7hn7 r:y2lwf 50 nm, enters a silicate flint glass equhyl: nrkf77w 2ilateral 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 lenrkgv ;c0oa( upkvf*pu 8yhhfx85a, 5-s 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