Does Huygens’ principle apply to sound waves? To water waves? Ej*v cw*c )eo:i*-uy rl54e0fi haby.gxplain.

What is the evidence that light is j8d3qli0ly*:-)/oxts s0hh k4hyj tienergy?

Why is light sometimes described as rays and sometimes as waves?yd e)77ge)n.7hst xxq7xh f1cxyv ef 2 5(cj1w

We can hear sounds around corners, but we cannbax.gg -rnb. 0ot see around corners; yet both soun0bbxna .grg-. d and light are waves. Explain the difference.

If Young’s double-slit experiment ,6 0yrut;lpa1 o/flkl5qlok* were submerged in water, how would the fringe pattern be ukll5qya/p *lokr06o 1lt ;,fchanged?

Monochromatic red light is incident on a doublwi/ z v )t+b63kutm*mq8 k enusd6;0bze slit, and the interference pattern is viewed on a scr+66 *m )td/b3zkkvun08 mutwq ;i sbzeeen 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 destruc6vvguclalxbm .83t ;3 tively interfere if their path lengths differ by acm.v ullb 3;386vgt xhow much?

Why was the observation of the double-slit interference pattern more cyy+yu c rwm1.k25-cvxonvincing evidence for the wave theoryw. x1-y vc 2yy+5mkruc of light than the observation of diffraction?

Compare a double-slit experiment for sound wave-jx a61q4 4ttxwvs nmz-tv 8-xs to that for light waves. Discuss 6v1 tm4a -x n4sqxtx-w8tvz-jthe similarities and differences.

Why doesn’t the light from the two headlights of a distant car produce 445p2p q eqofg2)0gzeeq1rfey ta 7 ;ran interference patt)r1yz p rfq;pfge2e50o g24e74at qeq ern?

Suppose white light falls ongz4-j )8qmrysb0gju4v+ i8 sits4hb. the two slits of Fig. 24–7, but one slit is covered by a red filter (700 nmz+srb8y4h0tvj )-.mj q4i4ss bg8g ui) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes 8gxcb2p6po-u through a flat piece of window glass, it is not broken down into colors as it is by a prism. Explp8og2 bpux6c- ain.

For both converging and diverging lenses, discuss how the focalz1;pkfnuf01jtg+wzlcyjc )( d.,rg . length for red light differs from that fu,c w0djz c ..1g);ftn+ kgpljz(r fy1or violet light.

A ray of light is refracted through three different materialshlkr;o* m)v, mm0fi7 l3mdjc: (Fig. 24–55). Rank the materials according to ti m7ofl j0d:;h,m)r3k m*lv mcheir index of refraction, least to greatest.

Hold one hand close to your eye and focus on 14qqypbpzb;)+mf+vb a distant light source through a narrow slit between two fingers. +yq4f +zbv1ppm; b)qb (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffracrq qf:s 0b wk2rgx6 pl/8r6kp/tion pattern of a single slit if the whole apparatus is immersed lfspgk/r6r:xqq p6 0b r 2kw8/in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (a) tj:ehy3/5 y.*ivw psclnk g6 ooa3)n+ehe slit width, and (b) the wj6py + 3vcks5noeny:h )wigl/eao. 3*avelength?

What is the difference in the interference patte /uv yw+oql u67tf6/ )(as+iwm unxuhk,h62bhrns 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)gyp zys/ i.t8a 56u6bxlh;qs c5: ok(h many slits, (b) closely sp8gpahl5 ss/;6 (zxyucbtk:. 5yhq6 oiaced slits?

White light strikes (a) a diffraction greou ttbb25ndr ) y6e52t+o0ubating, and (b) a prism. A rainbow appears on a wall just below the dir bdb2 or5tun)y 52bt+6e0ot euection of the horizontal incident beam in each case. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm (/.m( xd. wez k.rintj l(q9lfand 700 nm, incident normally on (kwi(zrdt/lx.9. fmel.(nqj a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only forp otunyz: /4 y sn9i i27pt(inp3:7uig a thin film like a soap bubble and not fopu7tpiy3nniy up osz7 (i: :/t 9i4g2nr a thick piece of glass, say?

When a compact disk (CD) is held at an angle in-/ wfmwpz8t t3r 93cey white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you w 3tycm8 -w9zpre 3/tfexpect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther ff ik;hagv4+pglr5 59from the center?

Some coated lenses appear greenish6c23d.xki scf;5- cdd wobs8y yellow when seen by reflected light. What wavelengths do you suppose the coating is desig6 wc.od3cx 82kdidbc ; ss5-yfned to transmit completely?

A drop of oil on a pond appears bright u0e 3b ock8syckqj/49at its edges, where its thickness is much less than the wavelengty 9k/b3s84jqkc o ec0uhs of visible light. What can you say about the index of refraction of the oil?

What does polarization tell u9kds wy6 pp.x:c 91ybks about the nature of light?

Explain the advantage of1mh-v w36al3qhd zf0e polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polari+yno5kp(- wg ahpx+ +lzing or not?

Two polarized sheets rotated at an anyisp 7ah9q.i )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 .o/ p0 ; goxbiahsu9;tof the sky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times densetzsk-.sb;.ceh0t; 0sbadm-cs ef3,ar than it is, would sunlight still be white, or would it be sk.b0s s-es dbzhst- t0c3.aafc,m ;; eome other color?

  Monochromatic light fallif9e( )br gwk8xng on two slits 0.016 mm apart produces the fifth-order fringe8bf 9krxw(ge) 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 obok*d.t .c5r l;jmfl0z1n ,h , ;*xoh ntmn9totserved 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 hba5ee)cx9 i;mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and ebi9 5;xchae)frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 at j kxlsm49(08wqs; dnm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the centeq;xl49d sj(wm0k s a8tr of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits anq1 ke9 ;o 6,qdk;eqg chfy:)rld produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 ); q1,lofrck9y ek:eqh6q;gd 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, )em8 lzg+ zic9* +vqrohow far apart are the second-order fringes for th+l+r e9iq* )mg zzc8voese two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of gqs( 8rya qwhle4(a+2wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of vis+82 e(ahs 4q(y ralqwgible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pas/sajwf1 nj-f6 8oq0hg e)5wxw s through two openings 5.0 cm apart in ax0 jh-w1wos6g8wf /eanj f5q) board. At a point 2.0 m beyond the board, 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 in Fig. 24–7 /a)ib 0vkf+k vso that the two waves enter the sli0/kf +vbvkai)ts 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-om yzgp ndpkz (9;q )(oc8aqu+gppa)/a5 g*y /urder maximum for light of wavelength 500 nm is locatedg)dp qump oay ugy+(5 zgpk; a)/acq8*p/z9n( 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?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. Find 4j5 qod9raw *mbv 9*xqsnt-k6the distance between adjacent brigh9s d5*q4x-wa*j t9 qkv6rmn obt fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in w0 9jjhbng9s2 iltj//5ufsx(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 of0znx mgezv/;-m+9osd(xk 3vv a double-slit apparatus illuminated by 640-nm light. The center point on the screen, igzkx 3(v0mns -9omv;e/ z+xdvnstead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the sp1ik sy/7f+k,chn rf25f x9by weed of red light (700 nm) exceed that of violet kf2/w,5rhknc7b x+yyis1f9f light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at awsm cq+;f,7-m p f6m:wjg)fru 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 containing two wavelength ,uk.zmqp0tz 4s, $\lambda_1\;=\;450\;nm$ 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 onpu:vkx: 9 uf,0zvrs6t a slit 0.0440 mm wide, what is the full angular width of the central diffraction pea6xz v,9:: urfust 0kvpk?    $^{\circ}\,$

  Monochromatic light falls mc7wm8s p*xoz1yu 96won 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 520 nm falls on myi(n. j (.ma*uqgwb3ss;4bx 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 byg t6+,j*wsbw ; fl ij/3yap2sr 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a screen 5.0 m awayi a yp2sfjrwwls 3j+b,/t*;6g?    cm

  Monochromatic light of wayiw9eh/:+k u 1 *,o dbxzy 7f)d:hxge-xniw0nvelength 653 nm falls on a slit. If the angle between the first bright fringes on either side of the central maximum is 3 bi0/9:dxi)x7h ywd1nykuzn +xg e,oh-:*wfe2$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m behin5yv9fbu /d 2 q3jjrntrtf-.)h-i8nbeed2t5 l d a 0.0348-mm-wide slit iti.yqhjd3 5r b/9)v2-n -8jtu5frfbden tle 2lluminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on aeamv:y rqat4o5gi2a5 si6 :+l single slit, the first dark bands on either side of center are separated by 5vali5s :t rmya5: 2i6qg+ae4 o5.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a sinnszl8p)k +4qdxk z0 ;j fxs;3ggle slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slix4pl;sz3gxf8)jd ksq+z k; n0 t?    mm

  If a slit diffracts 650-nm light so that the diffractioq zdyb-e u qb538:i2cvn maximum is 4.0 cm wide on a screen 1.50 m away, wha q53i q :zb2cb8vud-eyt will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengxdrak u.3: n+rq:o*kn th $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce6to(qzpwl q3(9 *wpef i5ee 6n a second-order maximum when falling on a grating whose slwp3zfwe 56*e9 l6((t qpq neoiits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a k4wufevagw33 jz))y 5 grating have if the third-order occurs at avga 35u3wzy4k f))ewjn 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 falling on aqx. qv5*gj5l r79my 3qak0,f2qe e)lu6tlnya diffraction grating is observed at a 3*9,tq v25kfa5r0m l7l eexyy) q.luqnaqj 6 g15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratin use78;x snhy4g 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 4zgod wm:spi3:v g5 p4./bga xon 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 q 1nb0qhxm*vp,mf r5jr+(s1 fbe seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume no0 m+q1rrq, jb1npm f5*vxs(fhrmal incidence.   

  Two (and only two) full spectral orders can be 4 z zw b5imeti,y 02)w4fr1 yn(dz+mfaseen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number o)+tf, y20zmafm4rziy d z1ewn(iwb4 5 f lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths*9 uoudrv0t0)a, xxbk3ml 5ta from 410 nm to 750 nm falls on a grating with rkx*ltb)x ta 0u,9v5da0o 3u m$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whi/tt e:puagl55 ch 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 specv,t ,l),tyfvs;hq ,rotrum 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, what wavelength is most strongly reflectefb57(sm knii* 8 2hsbfd at the center of the outer surface when illuminated normally by white2 5sif(78s n* kbfhimb light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the darkgknn n*hg1.- l fringes in Example 24–8 if the glass plates are each 26.5 cm long? n .*g-gk1lnnh   cm

  What is the smallest 19mavnmt2nji lg41g:,v cl ;tthickness of a soap 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 ye c-.ih8a9incj llow ($\lambda\;=\;570\;mm$ 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 darkmmyd*e(3is3d lw* /tk spot at the center) are observed when 550-nm light falls normally on a planocond mik3s(t/ew*md 3*l yvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically flatztjq((j ewrp2*c . l-p glass, as in Fig. 24–33. When light of wavelength 670 nm is inlt( j*cqwe .p zrp2j(-cident 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+k2l cnqw t t*.m(h4tq flat glass surfaces if the glass is to appear bright when 450-nm li*(knt .lqmt+hq4tw 2cght is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen dia5bmpq5 +uah3 l3m j i6b0bd,bqmond $(n=2.42)$ 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 alcohol cbo3vs + ((cy 5z)btv,dh(cqx$(n=1.36)$ 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 diam /hbk zozlj *t6z2*,w-a 9+ihmk rge.reter of thek+mt9 *6r/ zikgwhz,zb-j2 h rel.*oa eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometerxahd1fpl,u-s+ w3b9xl)9s f o if 644 bright fringes are counted when the movable mirror moves 0.225 mm ),bafwxl1d xsh 9+pl93ou-sf?    nm

  A micrometer is connected tk smqq+,0sjyddw/2 dq 1pv)(vo the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that kvw/0d,p+ j2ds1 q vyqs md)(qmove, 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 mir;od8 plf *2 rh29agzzyror $M_1$ 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) jbegn1 i//ym9passes 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 uig b1e m/ny9/jsed 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 o3tva hi/0nts9riented 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–glava.xl. cyr -qnl7a x6g3 1)ynpss $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is hitt6a1yucv +wkrxw3h,0 ;/kwjri ing x6kw+rr wu hajc;vky,0wi /31 the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are alifny5r;:i9 l(c a9 )kmbbj*kafgned so that the light passing through them is a maximum. At what angle should one of c kr*k59y(lff:b);mnj baia9them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to y b*kwxt 93x:)l5q mnlreduce the intensity of the incide5 *qxl9w3tmb:kx nly )nt unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orienwq 37ydtz( koq:h.v -lted 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 orz5, vtaxlot-p zo/+m2 iented 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 reflections off the surface of watgbj9dxw,r(lsk24 ff-exvl ;3 er for light coming from beneath the surface? Compare to the angle for total internal re 34d2-le9vk;rxfgj xfb s wl(,flection, 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 t89doiko 8,4 rmz .tvwyhrough five successive Polaroid sheets, each of whose axisw4i .yd98omzvk,r8t o makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength .qnf2 2-qa s5ji lt+i0rv s9go4qi5o j$ 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 can interfvs u06q(zt9 c ym(dt1xere with thedxty0vc(z 6u 9tsq(m1 direct 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 sour :n m/bom5lzlu,ow3 w9ces passes through a diffraction grating with z,l b3m9w:noo5w ml/u$ 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 v0pb1bh 8.e vmnm passes through two narrow slits 0.60 mm apart. The scrmvve b.0p8bh 1een is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operacp/.l n.g i-u7 xnathelv5ia syj+5f)u9yw44 ting at 102.1 MHz broadcasts from two identical antennae at the same -xs5lfj. tg.puvya 4h/u7il5n4+a9iw eny)celevation 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 outside doorway 0.88 m wide, and blows - 6yswf ezir*01:lz.ktxz j)o a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playgr -krizlxjyw. ze:*f6o 0z1 st)ound outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light fallskt4iozm p3vrw8(o61g 8vy,1jk2k ivv on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across them. Wh2o0(*bk 5z :ii- ndchht0spvq en normally incident 460-nm light is refcsi0h:2b( 5 -*pto ikzhd qvn0lected 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 te1q du0+wr blx;9 z9xk8j1lx yo be no second-order spectrum for any visible wavele0;+ rkxwldlyz 19 8 9xxujqb1ength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by a diffr:ofmam q*70vnu.rve1 action grating always overlap. What wave0q7 vu.av :erm m1*nfolengths overlap exactly?

  When yellow sodium li3(rkh*ya se5 1xdtb,j ght, $\lambda\;=\;$ falls on a diffraction grating, its first-order peak on a screen 60.0 cm away falls 3.32 cm from the central peak. Another source produces a line 3.71 cm from the central peak. What is the wavelength of the new source? How many $lines/cm$ are on the grating?
   nm
  $ lines/cm$

  Light is incident on a diffraction grating with and the pattern is vieytr shup42ppe,4v3f( wed on a scr(34ph4 tu sv,yerpf 2peen 2.5 m from the grating. The incident light beam consists of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clear materixpg13d2avai 4a. 8gp aal if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when ligh3 gxv. apdp4g 8aiaa21t of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incide a5:e yr ugp bxa s8,3efy/obns-l,32jnt normally on a thin sheet of plastic film in air. The reflected light is a ju,yalxbp g 85-2f 3osye3aen:/ bsr,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 +v (nk myeqw9;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 between twol:d0pm wm. fr2h j8me3(be 8b7ml deh+ flat glass surfacbfh7 bm8(380l mjdmmrled +2epe:w. h es 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 thin fil)k(9 fgkb, x0fgnqaky:hj*bq4 m +c7hm layered on a flat piece of glass. Draw a diagram, similar to F+ jhk mk*fg 07 ,q(xkn4ch bgfyq9:ab)ig. 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 theg0 ws- wze:q s(lk,3uz Sun when light reflecting off a smooth lake is pwz-:(su gsql3,0 kze wolarized most strongly?    $^{\circ}\,$

  At what angle should the axes ofgo3k7 sq08twi two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the fi38soq7t kgi0w rst Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose ec j8mz);bo1rq makvw 0.17j ftransmission axes are at right angles. A third polarizer is placed betwee m7 bke;w0)8qvr1 z.1acojfjm n 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 wi.c0ia s++a (beo2kc hith 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 ofd u pr ms--by01c:q+zbch3i t7t7opa1 width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from theso:y7t0 -brzaphm-c+bq73 11d c ptui 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 it reaches the Moon.    km

  A series of polarizers are each placed ptmy/mv tbh,* dounwuj5o;9+6 s4x m5at 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 kiqz*fh 7v.b 9$(n=1.34)$ 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-MH51ebgn m*bb 9v)g9c0ijaw 9ecz radio waves in phase with each other. They are locat9 )* 0w gjc9bvgc1imb9bne 5eaed at points $S_1$ and $S_2$, separated by a distance $d\;=\;175m$, Fig. 24–61. What are the first three points on the y axis where there will be destructive interference? (Destructive interference in this case means that a radio receiver placed at that point would pick up no signal).    m    m    m

  A parallel beam of light containing two wavelpuqi z x cv0,y26jk)sf 2wl*s9engths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism (Fig. 24–5k20 6us pvxl2*,cws9)jzqy fi8).
(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 ozs2p x/1d vyze+vzk *8ne 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