Does Huygens’ principle applybtoq:-3l ly)z to sound waves? To water waves? Explain.

What is the evidence tham rhuj7+k6sg4t light is energy?

Why is light sometimes described as rays and sometimes as wave-c/ gn 5;-g/w z4kkduwhh2xqbj ,gk n0s?

We can hear sounds around cornertp.,h)o6o.x x pkh. kjfrn6a4s, but we cannot see around corners; yet both sound and light are waves. Explpk, .6hrft.)ox .nakxo6j h 4pain the difference.

If Young’s double-slit experiment n.4 q2heooaxrz * gr,5were submerged in water, how would the fringe pattern be chanaro2 4q5,hgnz oer. x*ged?

Monochromatic red light is incident on aaola *ss782jycto34y double slit, and the interference pattern is viewed on a screen somea cto2l3*os7a syj8y 4 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 destructively interfere if their path lenl n)lroa*8ewp qptnde0 h*1 *,gths differ by how m1a e *elpw )nql8h*n,r*dotp0uch?

Why was the observation of the do 8-5as5jzw/ wqvr p(kf9hpm.m uble-slit interference pattern more convincing evidence fomk/- 5 j59 .qvazhw (wfprsmp8r the wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to th:2i7y3d b z7sktjq f;d9lrr0 vat for light waves. Discuss the similarities and dl3vkzb d f7:0d7y2 s9rqjti;rifferences.

Why doesn’t the light from the two ycp v57o t as44a(papnm8o86m headlights of a distant car produce an interference pattern?4t vna6moycap 4(os ppm7a5 88

Suppose white light falls on the two slits of Fifkbd. -/dh w9ig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter bw/f hd-kd.9i(450 nm). Describe the pattern on the screen.

When white light passes through a flatpqxk-dtd (f5 z:ja)m8 piece of window glass, it is not broken down into colors as it is t-zjdaf85: qp xm()dk by a prism. Explain.

For both converging and diverging lenses, discuss how the focal le gei/ 9 c20lczw:khamk4-rc-m ngth for red light differs from that for viol kiwc9: 2alh cekz04-/gmm-rcet light.

A ray of light is refracted through three different materials btub n.z.o4xm(9jb p6(Fig. 24–55). Rank the materials according to their index of refraction, least to greatest. ..9bntpjbobxu( 4 6mz

Hold one hand close tob1gop )q+s+yv4x+/i ngqmdne 35wa6 a your eye and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obvpe)wxmo gq63 +4/n+s+q5gn byi1d a atain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole appao9v o togx+ )zq7) g -liu6qhodgj(x+6ratus is immersed in (a) water, (b) a vacuum, instead of in ai9du -oioq j6gx+ov)o+7hgl(6x)z tgq r.

For diffraction by a single slit, what is the effect of increasyr g)dj;86gnd; foxq :ing (a) the slit width, qgy 8;)xdj:dfr6n go;and (b) the wavelength?

What is the difference in tkr;ssy( af :b ij41d9mhe interference 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 vzcemtz)dw6pg m 0rijs4lc pq-2.+. * the advantage of (a) many slits, (b) closely spaced slipdv)sr-g+mjc iz l4z w.t ecm0p 26q.*ts?

White light strikes (a) a diffraction grating, and (b) a prism. A rainboo o8)w:y tkr5x9 ya(6 k*sit ls;kkjc(w appears on a wall just below the direction of the horizontal incident beam in e ar ykc (kio:oy9(sl8t6* ksxj5;wk)tach case. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavel ,83vggwvns nn5j4 7jbengths between 400 nm and 700 nm, incident normally on a diffractivnjn8wsj 5g74 3n,vbg on 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 for a thin film like a soapc+3 fkx23jx idgzawm.0 )k c6rr5w(uh bubble and not for a thick piece of glasz.cw(fc rrdikwgja2 +xu h6 kmx3)305 s, say?

When a compact disk (CD) is held at an angle in white)x u,oug(4pcje; asd) light, the reflected light is a full spectrum jeu go,s)dac);x 4 (pu(Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24+y;,b g1 9q0 imwcgkgg–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by r.6rbh*ui1grmi,u*xud ;riy 6 eflected light. What wavelengths do you suppose the coating is designed to transmiu.um h6;r rri,iyg*1d*6uixbt completely?

A drop of oil on a pond appears bright o04pcf,zu 3 th-yxq;-;c-ysc7n crmyat its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of refrcr34p;shyfo xcqz-t; y-c m nuyc 7-,0action of the oil?

What does polarization t9hch mw1-ay me0(+lbd mh3 v8mell us about the nature of light?

Explain the advantage of polarized sunw y7fq+chsk6.glasses over normal tinted sunglasses.

How can you tell if a pair of sunglasse.eno; 0hram 0*8v3n,svxax qv s is polarizing or not?

Two polarized sheets rotate xh: ginwrea7a)24 7bfd 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 sky if the E3vdw:j* s;kq earth had no atmosphere?

If the Earth’s atmosphere were 50 times dty+*swo vag s-ioa7d .,t7t,v enser than it is, would sunlight still be white, aot- gsa iwo*t,,v .t dv+77ysor would it be some other color?

  Monochromatic light falling on two slits 0.016 mm at1 d0yfza k g*)in2j5rpart produces the fifth-order fringe at an 8. ztn di12)5 kfr*ajgy08$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at rh5wa -;-h ou1d;jplvan angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on 5fm5en9bvk))r e wqq/two very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m an5 5wkrveq )f)/qb9emway 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 las j*i,n. wp u.9d *;r8pgkv7f orut0mxser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in trsvpxw f8*m0k it . djpgr7*n uuo,9;.he center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm fal7g( /d)meiwxek1 -;skqvl4yt ls on two slits and produces an interference pattern in which the fourth-ordeveeki 4xw; t/m1-y)s 7q(dlgkr fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm lig+,b isd xn *7fupc u2v;ru1g7vj f.7ieht passes through two slits 0.58 mm apart, how far apart are the second-order fringesn 7buf;f77s1c ,*pixu2 ed.vjvrgu+ i 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 460c 12voe,xi5ufi4dug, 4)zv va nm gives a second-order maximum at a certain location on the screen. Whatuaug 4zx) f14ovdv,v52 ,ceii wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two openings 0ffperi7*1axa. * hhp5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relhfhe frpa p7xi*01a* .ative 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 o punu 3,dr72lso that the twol7r,3u o2pnd u 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, tv :jo2hjscv7 1he third-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from 2hcovj:j1 v7s 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 the d 81kjkz-;fgx,kz/rf*a1e: dfmzs. xqckr5o 0istance between adjacent bright fringes on a screen 5.0 m from the slits. fdr *f-z.kq ,: 5zgz/8 k 11komsexr;0jcxkaf    mm

  Light of wavelength 480 nm in air +(m7q zw nsdch(6,tr0o (txwbfalls on two slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a )iw kfugy , g3pk;+u2d: sbd1qdouble-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic? siw1fudq) :d+3kp gg,;kyu2b    nm

  By what percent, approximately,bfgy-d:s38ia f2m4 yu x(zd (l does the speed of red light (700 nm) exceed that of violet light (400 nm) in si-8x 3b: (y y4fdld2suifagm(zlicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of o9az.t8te5 qv0 t) 4x0c:dbhefrbtd 9rws9 c ;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 waveleq8d*v fy1)r /,tvs;sd w*ih yjngths, $\lambda_1\;=\;450\;nm$ 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 0.0440dpytoyrn,yz vipw;;9y :1 aw:zv6o1* mm wide, what is the full angular width of the central diffract d9v r;yz:yto1 1 p:;y6yvz*wpo,inawion peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that i+rg ve (rs/ msx-km(5ys $ 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 se8: f pn:*/wf9)flf kf)jpuvb lit 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-nm light. What is b.)jnlg*-b11a 2nh kzc+00g dnxdk1guroam( the width of the centr k) *akrc(0nug g1o dx01g1 j-zmhbln.a+dn2bal maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angle betwee.*qgl0* ld j wf;;rlxfp6tuic t: n-pi)dt+3nn the first bright frinq*-rp3t *gd;ln 6n;0 t+ itpfwjld:c.f)lu ixges on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffract736ub q nkza1j4s jp:aion peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminat a:6s3kbjaz 4j7 puq1ned by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit 6ktv3c1e 7q(yab zt m4p0bhg4, the first dark bands on either side of center are separated bqhp7m(1 06k3 eb ay 4gtbzvtc4y 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 41l+bsgyi1 v9dy+yap v q d/3t:25 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a +v+gvyy s9d2 b /adyiq3t:1pl screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the dif+ohrcw7ks0ixc 7:: i cfraction maximum is 4.0 cm wide on a screen 1.5k co+77 c: 0:rcihsxwi0 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengw lmo*bt8m p46th $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm ld4nyun) iz* 9gight produce a second-order maximum when falling on a grating whose )4nn dyizg*9u 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 centimhr h 0 6dqhpj0*0(k n7kd8qaimeter does a grating have if the third-order occurs at an 00d8*m6 jihaq qhdkhp(0nrk718.0$^{\circ}\,$ 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 1 ldyahmj8/xw cqd78(on a diffraction grating is observed at a 7dwq jhcdlxyam1 8 8(/15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating r/ psi.ck2aut)7x-ai 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+ndo9(01vyh jyw l9fv 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 spectraltea t/: 5q+ drwdm-9xq order that can be seen if a grating with 6000 lines t9aqr-tqd5x d+/wm: eper cm is illuminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on eithy n. hwbv h-yeh*51kd3er side of the central maximum when white ligwvhky 3e5hd1y nh.*-b ht 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 410 nm to 750 nm falls on a gre, r(x4qw7/0d u;dsj h eyaq5zating with / ;se,da0rzwqej(7 4hudxyq 5$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochro*pzavqa 7vzwc: q*/b1 2vu;eqy e-xj :r4z/ limatic 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 m+tkjs5ie8v5oo(e ( -v-ryhp 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 -vj f 9vmf 8ay3ny5ly2most strongly reflected at the center of the outer surface when illuminated normally by white light? Assume 2fyavlmf- 5njvy9 83y that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the gla9n /c au6p+e;i2f /fq jgmfallrqis 41 c3+f*bss plates are each 26.5 cm1qf2 l eip6fls*u ;b3jmr igq+cf /9/n4cfa+a long?    cm

  What is the smallest thickness ofv1 qiqktlv7 o2+y02 wj 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;rsc*00nl arx ellow ($\lambda\;=\;570\;mm$ is strongest) when white light reflects from it. What minimum thickness of coating $(n=1.25)$ do you think is used on such a glass $(n=1.52)$ lens, and why? $t_{min}$    nm

  A total of 31 bright and 31 dark Newton’s rings (not coun-iy(kojduupr ee2- 6(ting the dark spot at the c6kee-i 2 ruup( y-o(djenter) are observed when 550-nm light falls normally on a planoconvex 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 flat glass, as i2dvr;mg8q,ar,v p )cen Fig. 24–33. When light of wavelength 670 nm is igcdq m )rvrep2v, a8,;ncident 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 betwe,m8;v6nc xkf5h1 oadg en two flat glass surfaces if the glass is to appear bright when 450-nm light is invkg d1mxo58 ;fa6c h,ncident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen dia; hd2b6ihf o-qssx ,r*mond $(n=2.42)$ 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 alcoho -,g rmhdm(gcg3 3x4yvl $(n=1.36)$ 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 liqui3gd6l)a* h ) yxsna7zpd, the diameter of the eighth dark ring decreases from 2.92 cm t*gys3a a )lnz67 xdhp)o 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferomyk.e;ml0wg fgae235z6 ev q1eeter if 644 bright fringes are counted when the movabw l2 .5e0eegegy1 ;vkza3q6 fmle mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. Wheazpp/2a ;,*ft(u4voi1te sxun the micrometer is tightened down on a thin metal f* ixuspou/ p;2v,ft(zae t 41aoil, the net number of bright fringes that move, 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 mir5 j+u- auotn0tror $M_1$ 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 interferome2j9 pwp dfn+,xter (Fig. 24–59) passes 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 used has a wavelength of 610 nm. Calculate the inde, 9f2pdxnj wp+x of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientqemuz;l:-d 3cn ;hu ef;fv9qv; ak++c ed 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,xdtd enl0 lx ,da0k.+uw 28ozyc1 wy9 an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the ligi/nba(;9g p7 uysgss0rw:8 - c+ payirht is hitting the diamond a/+s c wy 89ar y;usgi (brspnpi0g-:7$(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light pan8t/fh8;fpd1x vtyq)vkh3p (um pe- 7 ssing through them is a maximum. At what angle should one of them be playtqkvtx p1dm ;( uh f)n -/p83p7e8hfvced so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axuukb os781 t sj,a.n6hes of two Polaroids be placed so as to reduce the intensity of th6nh87ua.,tsk u1j sobe incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented au g-box:m v:-i *smco7t 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 oc) h7fm( qfzr/uomuz ff8 7a78riented 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 water for lig(ga6k ;y/+-rc lv2h h9 esh7jtuon:kaht coming from beneath the surface? Compare to the angle for total int th(j6e akknoh +sr7/c ;:ug2-a9 ylvhernal reflection, 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 through five j2:nnu (g x//:wodivlsuccessive Polaroid sheets, each of whose axis mav g:dnilx o:/u2w(/njkes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength ur/w4 l +tub 7v+7da. wl,ysxi5 ezoli) u9d,g$ 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 airpla(xmtosmvi1 xq -77/e unes can interfere with th (ux -/q1soxmm7evt 7ie 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 sources passes through a diffraction grating wie( x14doelyjm )r4xs9gl;,il+ ln9pfqxxe1 7 th j i)eelgs; x4(+on7y 1xqm l 9elp x,r1f9dxl4$ 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 narpi l4f at zu:8:;kbp,prow slits 0.60 mm apart. The screen is 1.70 m away. A second s4pftp 8ak,:b lu; piz:ource 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 102.1 MHz broadcasts from tw5 4iiv/t*u q il1+9upyvgp)d vo 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 horizontally in both directions. If the midline is taken)*vd t+i5uqgp iuivy4 p1/v l9 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 m4 bf9t:pud6xn wide, and blows a whistle of frequency 750 Hz. Ignorp:utn xd69f4bing reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of widit4+33dda n.cqo e ,lrth D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain *ooq/wod ,1-c2 vuk yibeetle have a series of parallel lines across them. When normally incident 460-/o2y*w c1 i-,okuvoq dnm light is reflected from the wing, the wing appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if theh:c8vf 2 wn)f ied1k0ere is to be no second-order spectrum for any visible wavele)e0if d18 kfcwn2e h:vngth?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by lqfed,5r8a 5 x opn,8,*bssvia diffraction grating al 8e,,o lvrp5if5sn*8xdq as b,ways overlap. What wavelengths overlap exactly?

  When yellow sodium lighthatv.dis1mt(98hi/( sx ( g *sts ki6u, $\lambda\;=\;$ 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 5kpf 96rga+;/ dlik awa screen 2.5 m from the grating. T9 k6k/a5gwp afr+di l;he 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(t(7rm-oimfd nm thickness of it, when laid on glass, ismmori7- ( tfd( needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident nor6pg bj24r l1bymally on a thin sheet of plastic film in air. The reflected light lyb64rbpj12g 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 needed for an anti-reflective coating hy7 l6z 5oeb twl,4kry68kiq 8$(n=1.38)$ 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) thie8d/y * hhy1fgckness for the air layer between two flat glass surfaces if the glass is to appear dghhf/e* y dy81ark 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 film layen,v) vn5z r.rf co-lb*red 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 posvl,cz 5rrv*o.fb) nn-sible 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 the6 npz9y t6a1rk dnom1+ Sun when light reflecting off a smooth lake is polarizeddz1 t6n+a1no y rkp9m6 most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be pqci 6* la.6u8a+;vhi/x rc/+b omkwhelaced so as to reduce the intensity of the incident unpolarized light by an additional factor (+xl eq*/ihcah ubvc/6om.8w6i k;r+aafter the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets wjfbujfh5cb;g807gy 8te3 x c9hose transmission axes are at right angles. A third polarizer is placed between the first two so that 8j78gbc9cf3 fux tb ; ej5hg0yits 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 a2-kmp;7)e , y;btpokco,cgk9b. 0 xyy (ojciwith their axes vertical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 1.0 cm and is pointzubcz821+za/xpn j ,p ed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (+2jz xu18 z,nzap /cpbthe red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizer7ix x7l 1ecqdail+4p8+r7zh hs are 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 m;tj 4)oq/apa$(n=1.34)$ 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 phwoq kj8c2o(y6n;s pt ,ase with each other. They are located tkq cwo yo2,68(jsn; pat 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 contaiw lsltf o1+g+yr+ +g5 g7to1ynning two wavelengths, 420 nm and 650 nm, enters a s g1rg5++l+7on ot1fwsl +ygt yilicate 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 surface andp-a ism4oc8wm/34gm k 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