Does Huygens’ principle apply to sound waves? To water waves? Explacalz;qs)i .a+ in.

What is the evidence t8 75vmu/a rqfyhat light is energy?

Why is light sometimes described as rays and sfq+sj h,+h,qgk 1n 1zyometimes as waves?

We can hear sounds around corners, but we cannot see around corners;ro)z dxpaw 6p. +cm*7n yet both sound and light are waves. Explain the diff.d raz)p+w x6pno7*m cerence.

If Young’s double-sli5zndbw y;k / x)vqmc9.t experiment were submerged in water, how would the fringe pattern be v;k .qyznx w/9db 5c)mchanged?

Monochromatic red light is incident on a dou+e-et fbl*v. vble slit, and the interference pattern is viewed on a screen some distance away. Explain how the f.b ev*ef+t-lv ringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source de)tp g*0ry6uks -1agcn structively interfere if their path lengths dif6p0nugyt k)cr1- gas*fer by how much?

Why was the observation of ww .vbu9tdawi ygf 74e og,az);js 9o,,2jva,the double-slit interference pattern more convincing evidence foa4z9ae fw7wjd ,iob ty2)j,vgawv.;ugo,9 s,r the wave theory of light than the observation of diffraction?

Compare a double-slit experime zl- (;rj2xtzsk-n bj;nt for sound waves to that for light waves. Discuss thet(n z--2 sr;kbjz;j xl similarities and differences.

Why doesn’t the light from the two headlights of a distant )ewi)8 +hc qhola;r2i lg5v h4car produce an interfereahr lov5;ghi hq28elw)4+ )ic nce pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is cov bzt4xph3j97l ered by a red filter (700 nm) and th xb4z3l7hpj9 te other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat pie-4z ms 3rj4cjdce of window glass, it is not broken down into colors as it is by a prism. Explain-j cmzdj4 43sr.

For both converging and diverging lenses, dnabke*dx 18f)r/p q07,ljj tpiscuss how the focal length for red light differspnqabkfr0*tjl, 8d 7 epx j)1/ from that for violet light.

A ray of light is refractede30fs argux: 6 through three different materials (Fig. 24–55). Rank the materials according to their index of refract:eru 6 0x3asfgion, least to greatest.

Hold one hand close to yj u 0sw(l;1z2gq0 etsaour eye and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingersjza0 q1u0e2ss(l g wt; to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if sha; w.:g t81kwyzj*e the whole apparatus is immersed in (a) water, (b) a vacuum, in e8: 1ska .wjz*wt;yhgstead of in air.

For diffraction by a single slit,7 q3gljd6e)3k. 0xz)aeafl yk what is the effect of increasing (a) the slit width,3al g7qk6kz.ea)l j3) efd 0xy and (b) the wavelength?

What is the difference in the interference patterns formed (a) by two sl;nr56t 8uz, xp0pvxkq its $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantage of (ao o)1q/m- *vcfcv hze5) many slits, (b) closely space5mc1*he ofqzcvv) -/o d slits?

White light strikes (a) a diffraction g1hua4t *ab 81crt 6zourating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of trzu bhot8u1a1c64 t*ahe top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incident normo 03-ah4 fnouu6*xgy fally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your ans- f*oghxafon y 6u30u4wer depend on the slit spacing?

Why are interference fringes noticeable only oe o6cp1fegp+ +9k1 sgfor a thin film like a soap bubble and not for a oeep6o1g9 p1++kgs f cthick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the reflectel2 dp7*r/ h+;iinsnj nd light is a full spectrum (Fig. 24–56). Explain. Whatdni2rn*;hp+j i sn/7 l would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fartherwkq 5 m:ghsg,w53 sl5d from the center?

Some coated lenses appear greenish yellow xdr; kz6(u+ gyiid748uwv0 wrwhen seen by reflected light. What wavelengths do you suppose the coating is desig6k8 ;wdrxg0uy+ r(w 7idvuz4i ned to transmit completely?

A drop of oil on a pond appears bright at itmzi g:t4:zx/ ks edges, where its thickness is much less than the wax:z t 4ki:mz/gvelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the a+3);f+urel y nuddtpo8y.y. nature of light?

Explain the advantage 5cc8 r82yvltpk2d 6ew/yjfa; of polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizing or not b +qsx1xdrto5zb.z)q(; g -n, c)sgzi?

Two polarized sheets rotated at ani )awh7 tsh uw:jk1.u9 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 ivsd/2il9nblm z 5f2rc:kzmh5aw3j)7h 0a * natmosphere?

If the Earth’s atmosphere were 50 times denser than saffa7p*m2 hf(p7d2oit is, would sunlight still be whitsph7p f2 mo(72af d*fae, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm ap fok0o.juk9 s:art produces the fifth-order fringe at.oufo9 j0k k:s 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:z 8hr ig+1dry 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 apa:6wn0 y;tuqz3eyv ecfwm* 3+irt. Successive fringes on a screen 5.00 m away are 6.5 cm apart near i mfn3v; 6 wc3zt+w0ee:y *qyuthe center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from) dll(r94u)lhda3e( ql qq5g i a He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart.5 3 4)(lrle 9l(dqlahdug) qqi 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 produc 5l:dtm)d mp2bdr m*g5+ hgog p.,(bhdt41blhes 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 separation of mmo+hl,pd 5g2p.4 )bth dmg gh*rt(: d1bdbl5the two slits?    mm

  If 720-nm and 660-nm lig bdyo5lrpag*x0 s664f;h kc-oht passes through two slits 0.58 mm apart, how far apart are thahy g4cd6;l6-kf ox05sro pb*e second-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is fon4kt x kjm)t f3ypu:(8und that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the s4u(xkn:t pmy)3fk8 jtcreen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel cresf3hbleq; yc84 w8(/1wjgub xbts 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 what angle relative to the “straight-through” direction would there be little or no wavcl u8eqb j1xbf8/h;by(w 43gwe action?

Suppose a thin piece of glass is place4iaw+ 5jm bgfa*4ry1z , dih7xd in front of the lower slit in Fig. 24–7 so that the two waves enhwmig j5 4dazy+4*abrf,xi 71 ter 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 experimentxc1y,v4 bc6 cm,,x l1rpuqwq*, the 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 the slits. Light of wavelength 650 nm is then projected through the same slits. How fcrxcq pcly ,b,wmuq v*,114x6ar 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 5-0eq et*0ats6- xdtnh 44 nm light. Find the distance between adjacent bright*x 0-entte h0s6-aqdt fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm ijb;z+e26 ibihvjp 3s) n air falls on two slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a double-m/ ,77pxj1j vjs q.6bbdsf)mxslit 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? ,j6p jm/)7 v7sxfm .bx s1dqjb   nm

  By what percent, approximately, does the speed of03k4g2 9ofz x-xywv xj red light (700 nm) exceed that of violet light (400 nm) in silk9xog yzx0jw34f2v-x icate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece u;vtz,ux 5 ) :i-hw.yor jp, t1) gt1i;aycnrgof 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 wavelengthdkhxok en 2r 19 vca1)g6o5*jpcfm1. ks, $\lambda_1\;=\;450\;nm$ 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 w173wv,ii boq53j pgs0:r sfsa slit 0.0440 mm wide, what is the full angular width of th s15sviw3s7i:3ogj 0 fwqbp r,e central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit tf 12a;e- 08hsv(j5wufkx vk cuhat 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 dsl rxq+:)j(pl4k hz /jzl/0-xj/ odt 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 illuminatzvvp8c +j8 -hjg4cz-1tpz-i ted by 450-nm light. What is the width of the central maximum (in cm) 4cz1tj8z 8 c i-vpt vjz-p-+ghin the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a/:ssj u2ypa6w slit. If the angle between the first bright fringe:aj2psw u6 y/ss on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central dicx- 8f k+qq1tnffraction peak on a screen 2.30 m behind a 0.0348-mm-wide slit itq -fk+xq81cn lluminated by 589-nm light?    cm

  When blue light of wavelength 440 z( 1:3hkv7hiarg hu j0-vn8a unm falls on a single slit, the first dark bands on0-v3 (jh1za8knh7uuv: irhg a either 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 falls owjav,(ia )6 vyn a single slit, it creates a central diffractionw ai,vyva()j6 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 max vp o(vgpv;cb 8a6,hc)imum is 4.0 cm wide on a spg 8;v )hv6,bpac(vo ccreen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength 3 .dtxlsxj0l* jy6qkxfg51;dv -u8ok $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light pvhg,bo0 czd *vtzw6bc,64 c2droduce a second-order maximum when falling on a grating who 6vzg,dcc6cz0 b,v*t o h2dw4bse 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 0z30;h)2bufpe1 aoxsdavv , o7k,wfcthe third-order occurs at afs,0,1fc; huk zvx o32wa v0abo ped)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 diffrp:hcm6cs3j 7j/ /oke paction grating is observed 3joch:p7k m/ 6/secj pat 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 ha x,l63r2n tfxks $ 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 i 6ikrng7t y3/$9700-line/cm$ 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 6000a5+hzu)3 )+bjw2 tsf,ibr znn lines per cm is illuminated with 633-nm laser light? Assume norm z3rj z+2 sf hn+ut)i),nbbaw5al incidence.   

  Two (and only two) full spectral orders ch-g5lqb)kh hz 82;ifn an be seen on either side of the central maximum when white light is sent through a diffraction grating.q);8 2nf5hl zi-kh hbg What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths +6r*pvpb pxkhkjj4 ;1from 410 nm to 750 nm falls on a grating with ;6php p r41* jj+xbkvk$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light 5 xuujpk1r- 66rtrn+ tof 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 linevi 7+qhfj;7p ns 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 refleprg qmd9ih9.u p,:+ svcted at the center of the outer surface when illuminated normally by ws gu+m qr9 :p,vhi9.dphite light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Exa5yh sn:7+vqbhmple 24–8 if the glass plates are each 26.5 cmyn:v 7hsb5 h+q long?    cm

  What is the smallest thickness of a soap fimk k, c r/xx.4dg6+bailm $(n\;=\;1.42)$ 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 ye6g3sp qh.sc9y llow ($\lambda\;=\;570\;mm$ is strongest) when white light reflects from it. What minimum thickness of coating $(n=1.25)$ do you think is used on such a glass $(n=1.52)$ lens, and why? $t_{min}$    nm

  A total of 31 bright and 31 dark Newton’s rings (not counting t0nr(t rv 35j.cal1g8zwtx 9cyhe 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 .g(3zljt8wv c1 09c yatnr5rxthicker is the center than the edges?    $\mu m$

  A fine metal foil se a;8djfmtn .q/parates one end of two pieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How th./fd an;mq8jt ick is the foil?    $\mu m$

  How thick (minimum) should the ai3y6k;g3 ifzcm.p+zd u x (c+iwr layer be between two flat glass surfaces if the glass is to appear bright when 450- yc 3zpu(zx6+3gc.w+i dfk; minm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of beinj63(wsoj qt jdi l 9cgm h90vz-,7iid*g 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 1x 8-ja*s76m cm nufmnhpr)9z$(n=1.36)$ 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 apparatuf..d+c zvzfi n6r4bv w cu6)u.s (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark z i6 fdu.cv zv 4+.)ubrw6c.nfring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength ss4pyp0- m6q dof the light entering an interferometer if 644 bright fringes are counted when the movableq4m-ys ps6pd0 mirror moves 0.225 mm?    nm

  A micrometer is connected to t flkhvz tnfaz8h wf,luw0 : o1--g)4a8he movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foi08)ogaahl w8z--,:ftf wnv1hlz k4 f ul, 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 mirr yj+ux84 5akxwor $M_1$ 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 (Fsx ahlwwb6r3(f x2(f8ig. 24–59) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allowedf68(rl 2 (h xfwx3sbaw 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 ori(f tj0bo+ /ahky(rs ho mo-/-uented 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–glassm qw/ebb,mkd ,ymq3e- i0 +me-.ytgb + $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submergho4b4a ryhi447h; . dbtaquc1 ed in water if the light is hittinh4 1a 74abq ;buri4d.4hy tochg the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned s(u;g8.t ccggso that the light passing through them is a maximum. At what angle should one of them be placed so thg;(gt 8cu.gcsat the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to red 7j jj5+kd l.zs- g3d*d .dyc*dljr9sjuce the intens.d* j-7g5lsz+ k rd jd*9djsyjj3cl d.ity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oj i/c mm*sx.7mriented 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 oriente*8xht nse)9m* p0 pqjhb,i1tu d 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 surfacri xhqiq -;t;jdw7:2k v bct-9e of water for light coming from beneath the surface? Compare to the angle for total iqj hi:dt k97xv;qcb--2rt; winternal 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 suc bwp /m3a6wyh(cessive Polaroid sheets, each of whose yphba3/ww 6m(axis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength dc6yzfravpe62kw1xkm+zy i; 726i: r $ 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 be8tk o :cu :07r2mez/3s ibpat +xm(smountains or airplanes can interfere x e:t s 0tmb8iap:z eo+u(k7brs/3mc 2with the 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 diffracgin-9y2c03b+vvvnpsmz d/( 9 tbq 9yhtion grating with g+bbmp9s9 i0nv2vzv9thy(3c q dy/n- $ 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.2:jmo7md )o ek 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. Whatoj7: d)oem mk2 is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operatin7wbzr4( jz 2p+7k/uemirf a h+g at 102.1 MHz broadcasts from two identical antennae at the same elevation but separated by an 8.0-m jpzufmr7habw( +ki7/e+r z24 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 door4nlkufj sh :75way 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 clearlykh: 4n7suj5lf on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single s(b9knuxa mg 2.lit 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 acf u l nbq7:(lx0aze6-r()y 0fe( tcupiross them. When normally incident 460-nm light is reflectp:60 uux(ia0c 7rb- e (ytfl)(qfnl ezed 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 t gg4lxktrgo 6li29 95hsl ;*rvo be no second-order spectrum forvsg grk65rl*9 holi gx2;l4t9 any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white lightl- -l278vsitmqf 3).ty gp fymkjf.j 0 produced by a diffraction .0 -yflt7f2v pq i8.yjmktsfg3-mjl) grating always overlap. What wavelengths overlap exactly?

  When yellow sodium l mp5br (kd c0,pip)j0pight, $\lambda\;=\;$ 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 diffrachb, 4j ,d:jopq,xm3is .e8nottion grating with and the pattern is viewed on a p ,ei, 3h8joj bn4txq,o :ms.dscreen 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 refractiof fxfe *y-sn(i ,0(nbqn of a clear material if a minimum of 150 nm thickness off*(in-x,f 0 f (qsenyb 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 answer?

  Monochromatic light of variable wavelength is incident7*)jpz*0kb m-.ndb3s lqgt xp normally on a thin sheet of plastic film ibs)txdnlkpbjm-q0 gpz.73* *n air. The reflected 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 needed for an anti-reflective coativi 33-;dr9kqiifki6j j3/ vojng $(n=1.38)$ 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 c/0g0pt zamk.o( +ruhtwo flat glass so0 0(rtc. gp/ka +hzumurfaces if the glass is to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmshz 2v p.lh3ehhlwn4u5;km 7.itted through a thin film layered on a flat piecezuwl.5ph2 hlehhvk3; ns m.74 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 the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Su apq o:)rb)2qmg9vab 3n when light reflecting off a smooth lake is polarized most stronglbmqp bv)ra3 ):2goa9q y?    $^{\circ}\,$

  At what angle should the axes of two Polaroids bzganlyb )qv-hd(( *0-x u x+, yw3yrmxe placed so as to reduce the intensity of the incident unpolarized light b -qx(xyuv*d (r,hw )3azl-0gy bx+myny 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 sheets whosezvwexuo1 ahgfy; 694- transmission axes are at right angles. A third polarizer is placed between the first two so that its axis1 u;ovwzxh-fg a649 ye 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 .y7e;hms u1pz acfz1.placed in succession 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 o2d(dtpo- gaj bz06 al3f width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the tl02a3zj-6adg (b dpolaser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each placed 4l3s;o4xgz3 zi)0bqu*jy cvtt) nc 6a)uoj0bat 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 g1z 2v wrzubr-jf 1citea8)40$(n=1.34)$ 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 othk7ri f./8m of4c0 mwr7i. kpzoer. They are located at pop.f7r c8i. of7 m4kkro/ m0iwzints $S_1$ 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 lil1ys-5o;1 01uq j xk kaks;ao8; aixozght containing two wavelengths, 420 nm and 650 nm, enters a silicate flint gll; s;o0qo5suo-; 1 i1kx1akzjya a8kxass 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 flawpb. 1rmgn59:pd190f fqrplat 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