Does Huygens’ principle applygc,;3qptyba (*j5 pmkwl k8y, xgk6e) to sound waves? To water waves? Explain.

What is the evidence thatn 9yrfh 2 pxqdd2z uum41(z70d light is energy?

Why is light sometimes described as rays and sometimes as wavel( u 7p)/:tknjwt 2*zcq f8nwos?

We can hear sounds around corners, but we cannot see around corners; yet bot *,+gn3sn ftdl/d7gb2i m ylw:h sound and light are waves. Explam ldb /i7wggs+t* 3flny,2nd:in the difference.

If Young’s double-slit experiment were submerged in ,v.v3q,pbwk+ vm bd;zwater, how would the fringe pattern be ch,+zv3v b wbv q.m;p,kdanged?

Monochromatic red light is incidef)l .q*. jhavsnt on a double slit, and the 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 a bluea.fqs*)v hj .l light source.

Two rays of light fros tjh63f mlzfog kp6mrp4, )8/m the same source destructively interfere if their path lengths rfm46s/3 zh6,lp)mj8okgf tp differ by how much?

Why was the observation of tmn c:i (l7cgjr8 fne-*he double-slit interference pattern more convincing evidence for the wave theory of light than the obs8m cf-( *c:ijlne nrg7ervation of diffraction?

Compare a double-slit experimenthc5o gn45 dc2)u0i,afm* rixz r az2v9 for sound waves to that for light waves. Discuss the similarities and da 9rd4uocni m* hfvc2 2azx5g5zr,)0i ifferences.

Why doesn’t the light from the two headgy)h6c p .3wkyy:pex7lights of a distant car produce an interference :7p6hey.k) xc gpy3wypattern?

Suppose white light falls on the two sp ;b8t0 tf nju/pomc-(lits of Fig. 24–7, but one slit is covered by a red filter (700 nmp/;tmonbjf (0- tu8 cp) 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 notr g)fpn+9hxq0 broken down into colors as it is 9gn0)fhqr+px by a prism. Explain.

For both converging and divergingpxi/d.b10 pt9a6r,/o3 rr sw (p.yesg :gekrt lenses, discuss how the focal length for red light rr orte31,s g9:r px.bk0i/d/ e tp6.ps(agyw differs from that for violet light.

A ray of light is refracted through three diff1q xk)7/qlky-g qhcp9erent materials (Fig. 24–55). Rank the materials according to their index of refr/7qxqykphql gk-19) c action, least to greatest.

Hold one hand close to your eye and focus on a distant light source thro -ee-tf1 ob9ouugh a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that yof-19tb ue ooe-u see.

What happens to the diffraction pattern of/83+ qqe6f k/jens ..g*dlxisaoo3u o a single slit if the whole apparatus is imm/ x+l.q*q8ssg aedj3no/.u 3 o f6koeiersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a singl( hj7fcxj. e)r i//hmse slit, what is the effect of increasing (a) the slit w/e.irc shxf/7m( jhj) idth, and (b) the wavelength?

What is the difference in the interference patterns formed (a) by two s *-oh. /if/+ b9ofqjj liwoc /xd9*quglits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grat r*q i r/;cycgf95)ugaing, what is the advantage of (a) many slits, (b) closely spaced slits?9c;g5q ui fa cr/)gry*

White light strikes (a) a diffraction grating, and (b) a prism. A rainbow appe 0zyt;cn1un. wars on a wall just below the di0yt z;cwn. u1nrection 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 and 700 nm,(m )xr+y7my.qjapdo , incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer.,m7 yo a yjpr)m(+dqx depend on the slit spacing?

Why are interference frin xqpuew1-ni;1ges noticeable only for a thin film like a soap bubble andpe 1-n;wqxui 1 not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white 4/8qg5w bhwcnlight, the reflected light is a full spectrum (Fig. 2wq 45b ngcw/h84–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the centers, ebb1ossz1 3?

Some coated lenses appear gr w g*y+suo77ja0cf:tueenish yellow when seen by reflected light. What wavelengths do you supposetcso* 0+ :f7auguj7wy the coating is designed to transmit completely?

A drop of oil on a pond apzna)pl:fjx 5 , p4kvi)pears bright at its edges, where its thickness is much lesjp45 ):fzi) anx ,pvkls than the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the nature of ligh 0qbepnx1w6;cvn+ ej96 dvz,ht?

Explain the advantage of polarized sunglasses+ck62 vccp; a4g 9glsf over normal tinted sunglasses.

How can you tell if a pair of sun.kcu* *twp y a0qma4+iglasses is polarizing or not?

Two polarized sheets rotated atzzzwvm-)e , j2 zjigzg(3a z;) 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 sky if the Earth had no atmosphere?5 u-qs 9qy/y ehn3ig6u

If the Earth’s atmosphere were 50 times denser than it is, would sunlight s wh +tw(,4af (ympxn3ytill be white, 4ntw+ma y,yp3fw (hx( or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces theps)h)e)m twm vm;1ul - fifth-order frim mv htup) m)e-lw;1s)nge 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 obs0-b4p;55ay v rp w5o3hmsdev gerved 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 mrh l7tm jy6/ u764ztuom apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the6l 6t4zr muth7 j7/you 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 wavelengthcdy7 vvw 9h/a4 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the frdvh7aw4y 9cv/inges in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and produl9 e7x:7nv t 8v+otnuwces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe o8vot t:uxwl 77nen+9vn 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 farfb nhtgf5-e: k (39,omos 8xlg apart are the second-order fringes for these two wavelengths:mgbt,85lf(oe gx f3 hk9n-os on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blukza:0d ;ee8i00vsm-aojr t( i e light of wavelength 460 nm givesi;r(m-j otake 8e:a0i s0d0v z a 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 pu1h+;,689 +f5m rxf w0myfuppjxjgkikpx, ( warallel crests 2.5 cm apart pass through two openings 5.0 cm aw g m u5y pk rupxfk jx+01h8;xmf,i6,+j(fpw9part in a 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 gla -- yw+ vgobrtbq:t-8bss is placed in front of the lower slit in Fig. 24–7 sot+togy -w8bb qrb -:-v that the two waves enter the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the third-order maximum for light of wav4uvxiuv 2 pr0ogthi9 52t7gk4elength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far t0i 74rvvug5 9th24 poigk2xu 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 illuminamcktfv11 qu d6 *0wzrq* i)cn1o. 6avvted by 544 nm light. Find the distance between adjacent bright fringes v1cqf zkd*1.v i 6atqrmv)o*60uwc1n on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falkloo16. a6 +7gtlqhcq: rfux* ls 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 e-or) t a5hs62 ;lv7lq kkn0anslit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. anl5- e27)shl0rqotv6;kank What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700lwjqq2cn iw,a6pi,2i ,3s:wy nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fi2w i:,y, 3 w2sl wnqcpi6,aijqg. 24–14.)    %

  A light beam strikes a piece of glass at a 60. n+ n2xwfj2;bn2etpl5 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 li u(yk2r 8i7jeq05wv dight containing two wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm wide, wha6/li sh chkqo)m0oq1 3 fnva66t is the full angular width of the3 afoko16qhh 6qisnm/ 0c6v)l central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit tha rcby,ubv (mn*/w vo**t 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 fallsepq3 wh8(t5xr;ls80h ghy (pm on a slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide is illuminated by 450-nmt; wv +0snd-igi ;ldl-mwex. , light. What is the width of the central maximum (in cm) in the diffraction pattern on a screen 5.0 m,-w.d -s+ ;e imix; dlwvng0tl away?    cm

  Monochromatic light of 1oi.h,,o*i6/in vi;uh paa db4n( clrwavelength 653 nm falls on a slit. If the angle between the first bright fringes o ,aa i;lcd64(hr1/bn.o ,ipon*ihvu in either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraj7p cr* d95tpjction peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm lightjr d*5p 9jt7pc?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dipzg h 2wtdh657;q nga4, 4kqkark bands on either side of center are separated by 55h7gp knk5d6qw;i4,4 zah 2qtg.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a sx3 zppdt;5zu3/ f-js 7nd/e .fm ry1cjingle slit, it creates a central diffraction peak t7.sjz 3 5f1p te udf3-yjn;x //mcdpzrhat is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts , 5-y98lu z+h flxl6:tkbbj pv650-nm light so that the diffraction maximum is 4.0 cm wide on a screen 1.50pyf8l 9ux:+k5tjhbvb6 -,l l z m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength )ltyz; f4r r4lp oba/jczcr:9af*r / 3$\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 56da q09k/xta87zpd 3en5 tqsf ,0-nm light produce a second-order maximum when falling on a grating whose slits art80 a9,xp5/a stqz7 e3fkqdd ne $1.45 \times10^{-3 }\;cm$ 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 third-order o4.nrnm u,k1yvfg. 7kfccurs at ary..kun 1fmnf4 vg,k 7n 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 a di jf1scsuj+ba. 5 fm7vqip/)b 5ffraction grating is observed fbsb7jm jf +/1sau5pv)5i q .cat 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 hyo29n;n2tmfye2kamb) e /fb ux io-3 k48 tre8as $ 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 e(g;rb.w5hglo/)f44qgi+ 8 mvnrf w d$9700-line/cm$ 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 o )*tuh3 plyhn6rder that can be seen if a grating with 6000 lines per cm h )3t*hp6lyun is illuminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full specty* d oj;gui1u5ral orders can be seen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum num dg;*j5uiyu 1ober of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a grap2hvhhxoo-;r 39zr40jeg ws0ljtd 9.ting with9se9rh02p4x t-wl03 j.o;g jrvh hzdo $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whibgdhr3w.: xj;)kz gfwed 9 37ich 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 spectrum linknmsxk1jv/-oll71b 9 es 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 mostomzu0pk.,p7d .j)u rm+ ax g*e strongly reflected at the center of the outer surface when illuminated normally by whiteuo.+7* pdzj ,umkrmxe).p g0a 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 ar (x4ipmzmcdm6s9z:9gp ,haz -e each 26.5 cm lsm pdx4h(a,-cmz6 :9zzip9 mg ong?    cm

  What is the smallest thickneso(*(nybskaxporzqdxrj,5. . 2 : uy 6os 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 y z 0dc8be73v97llvuvqellow ($\lambda\;=\;570\;mm$ 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 ri *g c)p (fv)pxczve,h9ngs (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 (Fig. 24–31). How much thick )c,9g zx(pc)hepvf* ver is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically ofq6)- ew o)uhyobuf;luj 4s, :9vd* nflat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normall; v) bo j6u -lfowe*,qs9yuf uhnd4:o)y, 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 betfttu26h ; rp/pween two flat glass surfaces if the glass is to appear bp2h/u t fr;p6tright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspectj )pnf14raxj9e 1-tc.bedr5oed of 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 alcoh ujy.8 wb yi0r j lfe+:,r+l9k(huo:guol $(n=1.36)$ 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 liq pm(bj o3(xep/dscl 3t:b 1c;ge4p;r4fmkjm( uid, the diameter of the eighth dark ri mgp;dr bb( ccje1km /(l4x (t 3jse4;o:pp3fmng decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light ent08ses0t g ,jcuering an interferometer if 644 bright fringes are counted when the movable mirror,0set0j s ug8c moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an *)v.w hpn sfh-0yhug-interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty mipy.-- hv fwg*hh0s)uncrometer, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirr*owaquwj 8pn+m:h 4*xor $M_1$ 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 inthubqwip(d2x;v + 6m0derferometer (Fig. 24–59) passes through a small glass container containing a cav 0x(pbm+ wdd;26uvhi qity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientedw xorr ce2bsj0r 3/ r/uvigp263z)vc6 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–glass uug:zkuwwwy8bct hq;3,9*2w$(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is hip s i*, -fuejoww(f49ook6j-ktting the of-*si oko6(k 9wf pj,ejw4 u-diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximum.asiz038kb+r4 ;mkg+y hao r 7g At what angle sg8o+h akz 4k ;gbs3i ry+r0m7ahould one 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 the iny3(w,vu4muvi tensity vvyi u,(u4wm3 of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are o uqt 5jm,e2 b:qq:y1llriented 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 orxe c(auo jhb 8hpc-3 puxcyl,7c,0v,- 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 thifad6h2.sm6 mz(osu*rh/ 7 ose surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Bremosf7zh6/do m2s. * h6(sariuwster’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 sz:er6z 8arcp **ks-kquccessive Polaroid sheets, each of whose axis maqpk-8r : *kzrc6zesa *kes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength v vyyc b swb15lg,h qt8b67(2a$ 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 mountah)lz3ctpl-zpj:pai)8 *n uwh 1t m/3dins or airplanes can interfere with the direct signal from the staztdhn mw3 /hpl: itpp)3-ca8zju*) l 1tion.
(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 diffraction p62xhq :gm)bzgrating with qx6g z:mh )2bp$ 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 passe(infa di1/k)s s 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 i akd(is)f /1nthe 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 h+--gifoeu7(e(yp t+gzzmw 0 pqi65sbroadcasts from two identical antennae at the same elevation bute t5wgmi-7-p+(6z us(ipyo+0efgq h z 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 doorslu14:- c9hkiie nl:hway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) itu ill: kn9-h1scihe:4 is not possible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls ry0ye 8w*-0, 9sn)2x cxj ubp*phhid fon 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 serie+e5n8+j k5 f*dbyyp md8 k7hsgs of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing 788k5kf+gy+ydj*ns m hd e5 bpappears 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 ther5t vq.u,set6uv.bdp0 e is to be no second-order spectrum for any vvue,. vqdu5sp. t6b0tisible wavelength?   $ lines/cm$

Show that the second- and third-order spectr8h w(cn9wa;mxr ,ty 7sa of white light produced by a diffraction grating always overlap. What wavelengths overlap exactln97;ys t(ca,xw wh m8ry?

  When yellow sodium light,bq:c wf pefx5d )8r 4hd2zw q:cbn*/v1 $\lambda\;=\;$ 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 diffractij.ei+kasc::(z6f 7cw s vsu ;ion grating with and the pattern is viewed on a screen 2.5 m from the gratingisw;u z76i(s:cefvsj:. a+kc. 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 nmvx40g / vpt bvc6:u9cp 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 havevgb06cp u t4/9pvv :cx a choice for an answer?

  Monochromatic light of variable wavelength is incident normally on a thin sh (sbz6a ms5n0teet of plastic film in air. The reflected 0n6(zbms st5a light is a minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness ,cb.s,evp2bg(5pv nn 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 between two flat gla xoh,omoaru 0j7( q stsw745l)ss surfaces if the glass is to appear do4 (muao7qr5ts),7 0 xhlsowjark 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 filjkh5gs 6e m:)jm layered on a flat piece of glass. Draw a diagram, similar to jk6 )e:j5mgshFig. 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 horizo9 lbg j9b-px.hn is the Sun when light reflecting off a smooth lake is polarized most stron- bj 9gbpxhl9.gly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed svt xnx*kvv ee(g999v9o as to reduce the intensi(xk9e*vx9 vv9vg en9t ty of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets8 ii vur;9*wc8l q0 (xiyo.dan whose transmission axes are at right angles. A third polarizer is placed between the fn*x0li 8q;wyi.cv9(o arud 8iirst 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 tw.8-lqinh )psuccession with 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 d2 dvuvs63 rr2width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the widthdsr 622v3ruvd of the beam when it reaches the Moon.    km

  A series of polarizers are k7lybtvgg*65 each placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap fr: n-b4wy ,vr$(n=1.34)$ 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 antenna-w5;s lhdpx/7 k+g g ulqcqz5-s radiating 6.0-MHz radio waves in phase with each other. They sw -/xl5p c-u qdqgz; l+h7kg5are located 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 wavelengths, 42i imsq x r(w,6hmp,i;ad9 g3)2jqmp7a0 nm and 650 nm, enters a silicate fiapx i mmsgh2( wjiq9damq736 ,p,;r)lint 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 ; xwjp g/9;iic,g:y eesurface 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