Does Huygens’ principle apply to sound w6 n5*u9:ibzmv wpc(fraves? To water waves? Explain.

What is the evidence j0gox v:y7 :a1+ ae6txh/ qpacthat light is energy?

Why is light sometimes described a bqy5*5;rr5hy rgti4l:adqk 8s rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet both sp : td pywc1d+(kqyfi(p3 j9a4ound and light are waves. Explain jyak1q p d(w+d(4p9 tpfi3 :cythe difference.

If Young’s double-slit experim+;0zapg+h-xj- j4uz3z rs v ybent were submerged in water, how would the fringe ux+43j- z-yzr;b jzp s0h agv+pattern be changed?

Monochromatic red light is incident on a double slit, and thdc. zud*n.ufky wz9+6 e interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is replaced by azd .n*uz9 y6.wcd+f ku blue light source.

Two rays of light frohid9t2 zjpxg6(;w./*foz hxvj 3lt.n m the same source destructively interfere if their path lengths differ by how much?h.gi dtp36*/ l .(2jjz;xzxow vnf t9h

Why was the observation of the double-slit interferen1j bls5xd )jy4amb2. bce pattern more convincing evidence for the wave theory of y)5j41.mxlbdbb aj2slight than the observation of diffraction?

Compare a double-slihmjsi a8oe- qsck;y* (. j7f3mt experiment for sound waves to that for light waves. Discuss the similarities a8 kosi . 3(j-*afhq y7msmj;cend differences.

Why doesn’t the light from the two headlights of a distantmmwjs644* 6db3 ig7yf9 ;tkp l *wsjwp car produce an interference p6wjbs wpsy; i6 *fkwp3gj*d7t4 m9lm4attern?

Suppose white light falls on the l;f6t 1v0z k:oam8f(l)f mcxb two slits of Fig. 24–7, but one slit is covered by a r0f x6)8mc l:l( tfv;1abfmkozed filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through w0xvfo 9 k45/c mp4azc:d7xfra flat piece of window glass, it is not broken down into colors as it/9cdc 0 4z mrpvkx54oa:7wffx is by a prism. Explain.

For both converging and diverging lenses, discuss how t w s0dn41g9fnlrt f2zes/5p)uhe focal length for red light differs fnl9s/pd42nz5 frfgs )uw1e0t rom that for violet light.

A ray of light is refracted through three different materials (Fig. pdgm b:0ub+l3sf )r:d24–55). Rank the mrm3) dp:lg sf+u: dbb0aterials according to their index of refraction, least to greatest.

Hold one hand close to your eye and t spypj)6di .4focus on a distant light source through a narrow slit .diyp4j)t sp6 between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction/m hvj+e nc1z zqh4 ok6bew;9( pattern of a single slit if the whole apparatus zc49e vjkq+h6oz/b 1nm;hw( e is immersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the ef 09aky7(d qo6hmffxk nr ac38+xfb9z0fect of increasing (a) the slit wib0f9c86z( xfrd3mhy fkk 79 +n0qoaxa dth, and (b) the wavelength?

What is the difference in the interference patterns forp9p 2qkwk2 s/ymed (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 s6jy g*-5j;o efyup7u nlits, (b) closely spaced slits?p6*jjefo; yu g75yn-u

White light strikes (a) a diffraction grating, and (b) a prism. A vx k(0ej-x591 dcugwtpyz )) crainbow appears on a wall 5()x1c )cdyvp xk t-jgu9z0w ejust below the direction 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 wavelend1hwfs5bk2b0 d(cmz3 gths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed specdc( dws03m25bfkb1zhtrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a soap bubble ib,4 qg3l4zp85ogeok9 ,cdc iand not for a thiqceibg,ok8g434 oilpz9 5 c d,ck piece of glass, say?

When a compact disk (CD) is held at an angle in i +tso 688cfwr/cseqjw36i *lwhite light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to s3 6s / is+8fwcre8oc*wil6tjqee if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together faalhhjtdaihp+x b36r,.ml 7 + 4rther from the center?

Some coated lenses appear greeni - r mh;k:nookh:;o8tjsh yellow when seen by reflected light. What wavelengths do you suppose th:htn8 ok-: o; rmj;khoe coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness is m*jt i60wjf 4l(rzgr 1such less than the wavelengths of visible lir6j0l* zri s w4jf(1tgght. What can you say about the index of refraction of the oil?

What does polarization tell us about the nature of light? nq74svnjv ,e j+ymv9h/v4r/i

Explain the advantage of polarized sunglasses over normal tiav/ (0m1fhizanted sunglasses.

How can you tell if a pair oqpkmp1,4rh o/ 5ub)cqzhl8y .f sunglasses is polarizing or not?

Two polarized sheets rotatmqbdg .el296 .wnv.ph ed 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 sp0wjm+u bh ;ct .14lrlky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is, would sunll t40 3an9 j8enqcyfv3ight still be white, or would it be3v tf lnyn34jae8 c0q9 some other color?

  Monochromatic light falling on two slitsvl:l- vaa09uri q09h r:3 olnk 0.016 mm apart produces the fifth-order fringe at an 8.8-a:l 00a9rqn:il9l 3kvruo hv$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light isv8 iw*g:rzbz5 l s/:ni observed at an angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two very narrow slits 0.048 mm apart. Succdq2*(9b hh wztessive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determinedh(2w9 bhzq*t the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 n7y)sdza2 q 7duku;-h/ lbs,tnm, falls on two vat;z7)-y/2kq husdl d,bnsu7ery 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 and po jastt1 .3g9zwfl4i2roduces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. W.s tao 2tgl31 wf49zijhat is the separation of the two slits?    mm

  If 720-nm and 660-nm lightkcpcy, )q-7 i 7kp-tyn passes through two slits 0.58 mm apart, how far apart are the second-ordky -q ypik7cn-t 7p)c,er fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nm gy+t 3;ia qbhx0ives a second-order maximum at a certain location 0 ta ib+y3;qxhon the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel creso. .4b)ac.l 5m (uk7ertwvirvts 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 whatu( i4.).mkvvwrl7 b eoca. tr5 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 lw.zla.1uvk ii2d* 0ifower slit in Fig. 24–7 so that the two waves enter .fli wdi0a1 z iv*2.ukthe 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 tys z m;+po*p *ypd81tghird-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light ogpp s; 1dmy8 yo+*tzp*f 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 -)ria9 nj5i:wx mi f0alight. Find the distance between adjacent bright fringes on a screen 5.0 m froi-05 9fiwaiarxnjm):m the slits.    mm

  Light of wavelength 480 nm in air falls o o v3z0bw8jkbjo :2,+3;irjr zn,dkyg n 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 double-slit apparatus0h ia,ug)wnu.rg;u7df4s : rb illuminated by 640-nm light. The center point on the screen, insteag),0dng us4ua b:h7fur ;irw .d of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the wi*/y f:ak5nq /.j kzvspeed of red light (700 nm) exceed that of violet a* :kfky5i.wj/nv/ qz light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a pit, drtxiph0)3 ece 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 contaio(rt f4n-j9mv ning two wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm wiz./e.k0 8x dznovu6v lde, what is the full angular width of the central diffraction peak? vxzv6.80ed /.zkouln    $^{\circ}\,$

  Monochromatic light falls on a slit . f*(r;-cm s-xotz ednthat 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,sd3tan2tk -by if;8 f is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide is illuminated by 450u6x7jz3s y.om t6(jpl-nm light. What is the width of the central maximum (in cm) in the diffra7.3x y pmotlszj66(ju ction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit.lo:/a1 qxx/5g9 wxngi If the angle between the first bright fringes on iqa1gxxw/l /n:xg9 5o either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak w5px:*m x82vjh, cpgpon a screen 2.30 m behind a 0.0348-mm-wide slit m8 pwgph*:j x,2xv5pcilluminated by 589-nm light?    cm

  When blue light of wavelenhj;f1mwcw rdyb+,/ 9xgth 440 nm falls on a single slit, the first dark bands on either side of centerh m1wcfyjbd9 ;+/, wxr are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single sl.xlw e)yre+z5kd c3f+it, it creates a central y ld ke+w5erc 3)x.zf+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 maxit ebn52n8fd r :bom2y3ye,-s wmum is 4.0 cm wide on a screen m,2een5y f:8b-os b2d3ty rwn 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengthordwp9vg0j .gfp0os7iht+ o5 c m4* +s $\lambda$, 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 whe wo2j9fs/ *mupb 8dr9bn falling on a grao w9b /sm 2f9jpur*db8ting 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 does a grating have if the/;u;6gjx.k d enx:9jgvc o cc*vyz,q 0 third-order occurs at an 1*xc zkgd/ov0e;vc9 j: . jxqy ;cug6,n8.0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

  A grating has $8300\;lines/cm$. How many complete spectral orders can be seen (400 nm to 700 nm) when it is illuminated by white light?   

  The first-order line of 589-nm light falling on a diffraction gratin hqa 7x/ qxdln+ylt3 45yc;o3-jlybx 5g is observed at/loy 34 y-xqxdhnt;axycll 5+j37q5b a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingn:l9fauk 67g d 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 normall 8xcg)l4 yjfw,g7phk2hm e-x9dr8t3v)b cn :vy on 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 spec xh+ 3vw(2uf t4l9x+v rmv8 riwn98lyetral order that can be seen if a grating with 6000 lines per cm is illuminated ue3tw8l+ifyr9l vh xr4 8wnm( vx v92+with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of7xc8 sd5pqs d4 epm2w/5hhy4 h the central maximum when whpq phws5 h42sx4d87y5hc /demite 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 from 41 1 po3yymf/5vig0jf0v0 nm to 750 nm falls on a grating with/yo fmp i0j 3f1v5gv0y $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light ofc:2rmo iiu(b4if - h0u 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 specqxxqh g.- ;u+gtrum 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 refl757dcpc sil+x t/5 pqal7hx,xected at the c h+q 7x ,5sapdlt57xc/i7cxp lenter of the outer surface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass plates are wu(8ncv82emz; brht4puatq r kn-90( each 26.5 p;2r0n(8qch9bzk4amrv8e -nttu u(w cm long?    cm

  What is the smallest thickness of av*4 81a iulse (nz:cri 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 yellowd)g,8wfur 3 cn9p i6p:pde9wbjvh7+j ($\lambda\;=\;570\;mm$ 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 /q-5nydkb5zkxus s.- the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting kkn5d/ zu.s qxs yb5--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 flat glassu47o8c qhsb h4, as in Fig. 8hhs4ocu q b4724–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be)nxvs +iiamdi6 l7o.) between two flat glass surfaces if the glass is to appear bright when 450-nmvo6iasmd l) ixn 7+).i light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected b6.; cwr:bik 8h+spxu/urm1yj s-f4dof being a stolen diamond $(n=2.42)$ is submerged in oil of refractive index 1.43 and illuminated by unpolarized light. It is found that the reflected light is completely polarized at an angle of 59$^{\circ}\,$. Is it diamond? ----待选择----yesno 

  A thin film of alcohol dzmitls q16gkh x9(1 l:xm 8;qt,bd(f$(n=1.36)$ 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 immh4ov6wf qq-u 6.f fusg0a c1e5ersed in a liquid, the diameter of the eight0gve5q.a6q1-h ufsf 6w uf4coh 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 afjj-0hqu ztc.i rh;kf)i :/ mufze 83:n interferometer if 644 bright fringes are counted when the movable 0/refikz3;:tuj .-ic 8 fuzhhm) f:qjmirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an vkn909 0-opzl . wmsujf:,jqginterferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the emp,o9jujvlmz 90:qp0wg s.f-kn ty micrometer, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirroo:xo:v.b s 2vgn4dto:x/1 8p/lnvtxb r $M_1$ 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 througy: bo 4l.kom4uh a small glass container containing a cavity 1.30 cm deep. When a bo .l4um:k4oy gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are or+u (roy8 e xk2z2*p4rw xkze4dh-mm(aiented 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–zr n g;s74oaehu;l xjw20cf67 glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diuq81 *a;g sz:k)zgxpt amond submerged in water if the light is hitting the diam;*ugxp gak81:qzt)szond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned sb:u3 -o2nmx6jc fwfq 7o that the light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subse:bfc j6xqm-3f7 n2wouquently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids b p cyy;tad/4p4wvy: 15vo b-dbe placed so as to reduce the intensity of the incident unpo:dd4o/a1t ;-bb45yypywv p vclarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented yhbw(*s6 )jwx z6sf)ta3sid2 at 40$^{\circ}\,$ to each other and plane-polarized light is incident on them. If only 15% of the light gets through both of them, what was the initial polarization direction of the incident light?    $^{\circ}\,$

  Two polarizers are oriented at 38jz1t(381of -gmqtzq d.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 ren dn0r3fr,; tlflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflecti,;n0r3ftdlr non, 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 thr 1wm1r8muon.w,q, hqs ough five successive Polaroid sheets, each of whose axis makeowrmnm81 uh wq1, s,.qs a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength hiq /es (4 1-,t(lkwl w,pcjwb$ 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 interfyw 175+-ash,r uvpmzg ere with the direct signal from the sz,m7-y5 uwa +rvpghs1 tation.
(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 passgst/i l2h;f5l q2p7rd es through a diffraction grating with 2/q5slr7 lfdthip; 2g$ 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 59 ;an ;jj*fj,)a 1yxb0qij *ryg0 nm passes through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is the wavelength of the unknown0y n;aj,jfy ji; )axbg*r*qj1 light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts froxn q3kruesyt:m. 4 5o8jy :*xgm two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum sieq3*ty.k:g :58nxrouymsj 4 xgnal 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 55ee3*(: v-za gfpw1m dwfbqm back 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 *e- wzb am(3fgqwf15 vmp:d5e to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls onhmd/(l,-zq1dx y )lelb3x +rn 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 f7.iq (bpjg5xm7 -t6e 3fvl huseries of parallel lines across them. When normally incident 46l-gmj .3bv6tp i(q 77 uhfxf5e0-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 izjzy*m6u 5/ epf there is to be no second-order spectrum fo5pj em z/z*u6yr any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced byqk n.w12tq *ky a diffraction grating always overlap. What wavelengths ovnkq.1 tk*wy2 qerlap exactly?

  When yellow sodium light, pgb0:st o2wj* $\lambda\;=\;$ 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 viewed on()+u4p:(tv )slq ggbixb ikz8 a i g)si4g bv tq:z8)k(xu+bl( pscreen 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 material if a minimum of 150 nm(snjm le pb5b 8uo((l1kljr0r 8au6v. thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an ans b.61m8ue vn(uaj 0(rkjp(l8 bsolr5 lwer?

  Monochromatic light of variable wavbfm:xl j6uli 35 /c-3yjp6 kwyelength is incident normally on a thin sheet of plastic film in air. The reflected light is a minimum lc3jy5x6bum6yp il-f3 k / :wjonly 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 ggh0b6zrt-;pj tjqi*zyio v (99k4:s 5dx:ra 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 betw*d*yijty5:m+d ny )bgeen two flat glass surfaces if the glass is to appear dark when 640-nm lighyt:m)* g dy5ijn +y*dbt is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted throuf8klph 4mh:,fyhh ;; jgh a thin film layered on a flat piece of glass. Draw a plhyf:8f4hhk j ,; hm;diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the k.)6gcger t0 fhorizon is the Sun when light reflecting off a smooth lake is polarized most str tf6.)g ergc0kongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reducef3ne 4ejt5 ee( the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) oentf5e3 e 4ej(f
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transm ge1mg r. kx-g,4ze;bsission axes are at right angles. A third polarizer is placed between the x;m bg-zs,g4.rekeg1first two so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axes verx6kmgtk- ,ds- tical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 1.0 cm and is pok rh9wtj5 ;uj82 xgtt/f,xt-xinted at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavet8tt5fhkxwr/ -x ux, 2j9;tgj length 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 e;fz3pou7: y:l.rqvaxhxq0/j - k:rj q ach 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 776.2zhwyudm. s3rax e e5xrl $(n=1.34)$ 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 phase with each other. tcgvj ,yvc,(r55 m tnq )btaoez/r18 oht2i83 They are located at pointov5vco8/a icj 3y) n,t8tt5zmh r,2(eg q r1bts $S_1$ 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, 42-ih )dv k8dwnsy23e0* l u3tdy0 nm and 650 nm, enters a silicate flint glass equilateral prism (khdsv*yid2l )3 y0d tenu-3w8 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 fzu2,)v mkybd,3j;alu lat 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