Does Huygens’ principm)xa(l6a (inyy dvszk 7qz 6wj4q(t88b1qv m4le apply to sound waves? To water waves? Explain.

What is the evidence that lig-2w5ztx i3xr/5wjfyk/k vn y/ht is energy?

Why is light sometimes described as rayyo6czir5 uqz 1z-e) b mc/wd9*s and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet , dcu- myaajr 2h6+2tkboth sound and light are waves. Explaydakc,+r2 mt2-ujh 6ain the difference.

If Young’s double-slit expe h29e( h.h;grnln 5ipvj+y( l buk36zkriment were submerged in water, how would the fringe patterh 3(pkhevi hgj(.u;2ln6nbyl +kz5 9rn be changed?

Monochromatic red light is incident on a double slit, and the interference patte .nvjlb .*ye*v g83qglrn is viewed on a screen soml*v qj.3nvly.gbeg * 8e 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 oi1a+f:yoo v: the same source destructively interfere if their path lenao vooy:f+:i 1gths differ by how much?

Why was the observati4jh2pkf 2: qu*kv 3dt73x oazron of the double-slit interference pattern more convincing evidence for the wave theor2 kd:r 4kao 3vqzufp3h x7*t2jy of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for light waves. Dupl*;h, :hz rziscuss the similarities and differelzp;zuh,: hr* nces.

Why doesn’t the light from the two headlights of a distant car p)vue j36qt*vh a+ ++yhrl z+vz;wd (pjroduce an interference pattv;vw+zp za) rhe(hu6*l+y+ 3qjdv tj+ern?

Suppose white light falls on the two slits of Fig. 24–f+ 1r7xinh5o5u7 cqc l7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the paq77lf+ ic1n 5r5xhuocttern on the screen.

When white light passes through a flay.bptlg9;usirrczz0 (-np 5) t piece of window glass, it is not broken down into colors as it (spt 5lu .r0z)z n9ciypg rb-;is by a prism. Explain.

For both converging and dij se6e,;nspr.verging lenses, discuss how the focal length for red light differs from that for violet6ps e,.r jse;n light.

A ray of light is refracted through three different materiifgf+-.q +lqrg (v5 bf2b1b lfi0av1uals (Fig. 24–55). Rank the materials acc-.fi1 0+bfl(g25v quf1q+ lgf avi brbording to their index of refraction, least to greatest.

Hold one hand close to your eye and h 8scdtow)nrnx;at8t,6:q3s focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best patte, :q88sx t)ttd h;cnroa3nsw6rn.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole apparatus x*gp(e w- uxv2is immersed i-(pwuxx v *eg2n (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increas99pt(de15 bu1 fpebsk zsa:u2ing (a) the slit width, and (b)p1s ezf9b bued(k 5t92ap:1su the wavelength?

What is the difference in the 7wzo uha9(fu(57 a rwss y78qvinterference 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 theu) 50yvvj.v/qnle e2 u advantage of (a) many slits, (b) closely spaced slits0v 5lu)yeq./jv2uvn e?

White light strikes (a) a diffraction grating, and (b) a *inybn .(h;l3no i;liprism. A rainbow appears on a wall just below the direction of the horizontal incident beam inb ;;i 3ynnh*lo(ini. l each case. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavelengthsln fx 1461l54irbc kjm between 400 nm and 700 nm, incident normally on a diffraction grating, for what ord flcn j6kxbr5il14m 14ers (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin filmku 40 )gb*ozqzt/q4cn like a soap bubble and not for a thick piec*z z gb /)tqk4cqu4no0e of glass, say?

When a compact disk (CD) is hfvk f::vr*bpj 5ql:et611z iy bb2d6held at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Eqb6yt6:b1bep fv :f1zv*j2 rlk:h5 idxplain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–39tcqfposo( hnw4rb8n n5 m 4 6q0wk6:c1) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What o-7;dp,2 pemqrj1 xeq wavelengths do you suppose the coating isj, 2px7-pq1;oeeqdr m designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickw+d/e( wzm0 wrness is much less than the wavelengths of visible light. What can you say abouz r w0wdme(/+wt the index of refraction of the oil?

What does polarization tell us about the nat(iszb+ jt,uw ;ure of light?

Explain the advantage of polarized sunglasses over normal ti:8pizmhb*3g snted sunglasses.

How can you tell if a pair of sunglasses is polarizi ibn)eu4hw o+8redy :a )yjfm4el)d8)ng or not?

Two polarized sheets rotatedi5g 61 3m*zyvbguus o3 at 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 skgj6ir9kob1 )6 -x bs)hozfc4iy if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 tkb q8( 21fwihf+wf .ojszq)/dimes denser than it is, would sunlight still be white, or would it be some oto)zffb8f1k w2+jq.d/ h(iwqs her color?

  Monochromatic light falling on two slihq .*d77fisu(l izt zvm -i06qbp4 8m,,hvs kots 0.016 mm apart produces the fifth-order fringe -spm *s8ik,l.f zt 0z qo47bh mid7u,i(6hvqvat 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 observeeg bc (rp gq5:hw) owij/0i5u-d 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 mmhwriduu 6/-me7: a x6q apart. Successive fringes on a screen 5.00 i6aq67xde/umhr w- u: m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wai*s- u.dzx hg 0(jzn8lvelength 656 nm, falls on two vzdj h*0 zl sux-g.(8inery narrow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits 3 gwwxr 2b512respx2ar kz8(or*d 6dyand produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the sepa wdxzo(rb2 x 56sgy2a r*2r8r d31pkweration of the two slits?    mm

  If 720-nm and 660-nm light passes through twhhuccosb6b/732 pvexyt nisi9r :q/;sx( 4 h*o slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 m away? vyxoxb6/7 i s(e4/hp*suhqic s9h;b:rt32c n    mm

  In a double-slit experiment, it is found that blue light of w3 rfc k8+mg qimd- f;r,5:loi:ohtn4gavelength 460 nm gives -tq,fr4:gnl mh;rdig fkm c+38 io:o5a 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 apart q6v ,i/jnera,pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the br,j,n 6qi/aevoard, 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 inrx /sb9v8o y 4h5mz-vf front of the lower slit in Fig. 24–7 so that t-9 bxr4 hmv o85/fzysvhe 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 thirt+sm5x mcn7ijd 8a7 )1rzq ,qid-order maximum for light of wavelength 500 nm is located 12 mm from the central brcj,7xs1t)7iaqm zd nm8+qi 5right 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 mlvmzh )y+p p3qw7ylxk+g0i41/ q qot3c l ns,0m are illuminated by 544 nm light. Find the dx1c k yq7/t3yw3lqp+q ),smvnlzgo04phi0+ l istance between adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air f;ve x* 1 h.po(z0vlnkyalls 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) coversaq /8n5 uywh9v one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the scree8nua5/q9vwhy n, 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 lig7tq h.1agin.uht (700 nm) exceed that o7.a 1qhu.itgnf violet light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a pie*ulb dwzgi12f 6y :-ykz+pv6 owumv(9ce 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 containing two wa+k;84qc.zzc y hgo.3ow akb /kvelengths, $\lambda_1\;=\;450\;nm$ 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 falll.m+du syk52e s on a slit 0.0440 mm wide, what is the full angular width of the central diffraction sl+5m u.ye2kd peak?    $^{\circ}\,$

  Monochromatic light falls onl f ib*fk/6(gezr 7at* 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 a slit tha0tarn9 0 bq*fyjue0 p5t 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 ixdmsbs;( ,0tslluminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern0,m;d x s(tssb on a screen 5.0 m away?    cm

  Monochromatic light of wave y5unf sf0dl5 dp0z. hi;4f/nslength 653 nm falls on a slit. If the angle between the first bright fringes on either side of the pl4nn .0fd 5iuy 0fhdfs5;s/z central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2nq2 yurhys c)b+x wx)0txz9+)c6z qn+.yo,f a.30 m behind a 0.0348-mm-wide slit illuminateq+s)6n 2o)afx+yy )crytx +nq0w.zz hbu9c,xd by 589-nm light?    cm

  When blue light of wavelengtd,25; xo -pf; ifr9mjce a0dnwh 440 nm falls on a single slit, the first dark bands on eiixmoarfdcw;5-;02f j9 ,nped ther side of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falc7pwk8 b fcd5s dk3so1ms+a*8ls on a single 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 f pmk75d8c8+c *dbs wos s31akthe slit?    mm

  If a slit diffracts 650-nm light s1v(3,b 9v9as p4lnz xap:abqlo that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffrac31xaq,aza ( :9lnp bplv s4bv9tion maximum for light of wavelength 420 nm?    cm

For a given wavelengthe5 vs 33uv9yeh $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-order maximum when falvgoeb :c:; rix.mfw*8ling on a grating whose sw x.*obm i8rgc;:: fvelits 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 grating have if the thirdeylz)hp 8nwm19b l5n --order occurs at a ) 9yeznm815 -hnwbplln 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 5a,wfm mszk-z1 g kf,/189-nm light falling on a diffraction grating is observed azm1m kf1k/ waz g-fs,,t 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 hzjqt.ih543 6ro a4gpkas $ 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 af43ox xryi,n0vqa na7o p92c 5 $9700-line/cm$ 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 zf53rt xk0l*x//x cng. 6ysgn- -acqllines per cm is illuminated with 633-nm laser light? A /. csxlnc 5f0 azlgxtkqg/r*x3ny--6ssume normal incidence.   

  Two (and only two) full spectral orders can be seen on eit tu:oto 6yx9 my2q(1xjj l76bzher side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the gratintoum zjx 9( 7bjqoyt:266yx1 lg?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths fromkj 9d rn4/fs5n 410 nm to 750 nm falls on a grating with s9nkd5rnf4 /j$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produc*l s)u2yj1ra+5 ezx hnes monochromatic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum lines 0i ;ogx*gkt)s;bsoj*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 ep5cqzjt 0):i (y9fbvm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by white ) cvy9 tz0eqj fi5pb:(light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 x 5y:iq.cjbyyd- l;x4if the glass plates are each 26.5 cm;j l d.qyyc5x:4xybi- long?    cm

  What is the smallest thickness og/3 qs-8s.qa4)7odpljj nzt tf 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 yel3p6.x298 *dkhlk il w+kg atphlow ($\lambda\;=\;570\;mm$ 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 dar k kh2hg-t et a0*d7 j7-vddj19goggs;k spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat gl1 otj*s -a7d h092;dgkgj g7vd- kgethass 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 flat glassfr3 w2x1 try/k, as in Fig. 24–33. When light of wavelengtkr1 wy3/x 2rtfh 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be betwed+* 1pwib) git;esv tg z1j p5*cwva8,en two flat glass surfaces if the glass is to appear brigh ;w it ji)*,dtz8v *s1agp5bv1c+wg ept when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolena1+k 3gnv,w b/j7 tpbt 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 alcohuuvz ;-r+6sh4khc e zkv1drk:(+(r y gol $(n=1.36)$ 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 immersedied7 .m 1rg f/dvecxs m767o5,h ykby- in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?him.-dy6y 75o7esr7 f/ cx,mb1gekv d   

  What is the wavelength of the liglp+6:bqaghim+ n jh 33ht entering an interferometer if 644 bright fringes are counted wmai+qh6n blgh3j: 3p+hen the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to therb.c 2a5f8v ia movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer, is 272rcf2a 5 ib8va.. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mire0fp n j+wevnf6+a 10xror $M_1$ 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) pau7*e x9msill(sses through a small glass container containing a cavity 1.30 cm deep. When a gas is allowed sll(e 7m*xiu9 to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriends 24j/; 5qghzd*ifqb ted 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 y2uya jt6htcw 7+an:q 0czo) 3an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged-cf1yr2gslk ozw3)s , in water if the light is hitting the diamond) 2oz yfc1lsg3r kw,-s $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light :zd l8/swnt *k9kod1m8w c)gppassing through them is a maximum. At what angle should o1k*8gkw:z d od89)pn /tm clwsne of them 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 reduce t,we8 cig) xv2xhe intensity iwv2 cex,xg)8 of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at 40ged m )::s(a81qj0 qcfzc w./ovhew j5$^{\circ}\,$ 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 or01hj:y 6*pyo-a 5,jdv/owm 4 ;4 xcpvskuhobsiented 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 bz vod6z:8h4d :ewec1the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surfacewb:vhzd4 o8ez d:e6c1.
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 lq(zy5lyg wo-4i x- 1iof whose axi- gzi 4yo-i1y qx(l5lws makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength qj/ jcra awd (m3dk2)h4)3 xpfs*uer8$ 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 inth7erp;cdmfd 2 8iv:h0erfere with the direct signal from the station. rmhhpc8 2d:0; e7ivfd
(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) cpys:dx0w -k-r3 xfd passes through a diffraction grating with )-fkdr:s3xc wdyp0 x -$ 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 apart. T5 p nz1zh/ya1the screen is 1.70 m z na1z/1 5phtyaway. 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 operating at 102./p 8 om*tur1tj1 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 midpoint and extending horizont8pmt/ut or1j* ally 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 b:;2hhan il 74v8 xjurnack from an outside 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 whistle clearly on thexh nha ni8l:2vrj 74u; playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single ee,nwnq6 x87ry+t l3aslit 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 t a 2/;m6zbdctkhem. When normally incident 460-nm li6/mcz bdak;2tght 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 second-or h l,):(jcnavnder spectrum for any visible wavelength? h:ncvl ,aj)n(  $ lines/cm$

Show that the second- and third-order spectra of white light produced by agn+rqn. z55.nxwy uyjg o;8 t: diffraction grating 85wnon+;g5yz. u:n.x yqj tgr always overlap. What wavelengths overlap exactly?

  When yellow sodium light,1pd y6k)) hp x:eh*qed $\lambda\;=\;$ 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 qu;o/ *1giug-+i8qtfnbs yn: and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of two w onfg-q*u8;yi +nbtu s/:1qig avelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 cle1+mhamtd ;t2hahd/v 1ar material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero w/tm2 h dm1vthda; h1+ahen light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wav d03u kku;jei)elength is incident normally on a thin sheet of plastic film in air. The reflected light is a minimum only foruki ;ej0uk 3)d $\lambda\;=\;512nm$ 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 coas-r,u un *ve:5/b n/9m+abfjfb z g5flting $(n=1.38)$ 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 fl(r7 ieno jg :ek5gp04dyu ,ge-at glass surfaces if the glass is to appear dark when 640-nm light is incident no40k-:dgep,7 5ijre(un ogye grmally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film cx 5 0ms7rfmy( bm.-jqlayered 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 xs .0m y7 b5-qr(cfjmmthe relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon isk 8vliktqm2* sru*e2) the Sun when light reflecting off a smooth lake is polariq2 kt*kmr8s)el2 * uivzed most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroidyz,m5gj8ut5d g466qx;*- nd glx4mzyiik )uxs be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Pd4z xuzm;5ixng -8dul6gi* jxyt4m65gkq,y) olaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets who 6kbul;22jm qq7vu -sdse transmission axes are at right angles. A third polarizer is placed between the fil sq;du7u2kb6-jq vm2 rst 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 wid +c0/ cxv(wsjx5bw5fth 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 1.6t-mbp 5 o 6yyzsd)xt2svh+dsp;g8 0o0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wt hp8-bsopv x;5 om6)d2y6sd0ygs+zt avelength 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 easa: lihw233 fech 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 , (xf*qied1co $(n=1.34)$ 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 w-pg:gp(/ ou*nn t,6cq rt xu4laves in phase with each other. They are located at poino lp:/,gn-*tnp t4u(xcuq r6 gts $S_1$ 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 650 .k) xi xsnqm;xo06bytwet63+nm, enters a s q3x+en6x 6 tsk0;mbxyio t)w.ilicate 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 one flat surkoq7y8bfp85oa:xu k, p i;hb-face 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