Does Huygens’ principle apply to sound waves? To watne/d l74,pqhter waves? Explain.

What is the evidence that lidih t 5fqz;/ ijmw94lt5mg*y/ght is energy?

Why is light sometimes described as rays and sometimes as ;z8fv(l4 mk;;luo ,/z(ko rymfjus+e waves?

We can hear sounds around corner9 n.aaog d;olq g-h;i*s, but we cannot see around corners; yet both sound and light are waves. Explain the differen;no .hogd lg;-q9a* iace.

If Young’s double-slit 3f+y5qzpudwvm ,y+o2mr;r m: experiment were submerged in water, how would the fringe patternm w2:p+ fm;5rm+uv 3ryy,z qdo be changed?

Monochromatic red light is incident ffzl7x sx, 76ucz wv v-m(0/boon a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would cucb/l v0vw 7 foxf7-xszz m(,6hange if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if their patg 2mayhe0 pjdy0i2e 5+jw pya;v( 7ig7h lengtp7yyme7a2v0 +5 2pdejg ayihgw0;ji ( hs differ by how much?

Why was the observation of the double-slit interference pattern more convingyjoc)47 b.tv cing evidence for the wave theory of light than the observation of diffrat ocy4jg7 .)vbction?

Compare a double-slit experiment for sound waves: cin cowh8w;48lu yk+ to that for light waves. Discuss the similarities and d 4:k8wc8+yliucnoh w;ifferences.

Why doesn’t the light ,n 9wefob,1c(4 ihjrq from the two headlights of a distant car produce an interference patternr(ij,h e1n,c qofb4w 9?

Suppose white light falls on the two slits of Fig. 24–7, but7uro. heah*vkfv0y,g1 /db+ q one slit is covered by a red filter (700 nm) anh17k0,yfago*qv .ud/+v br ehd 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 not ugz8y ;r5) sz*jj-i zrwaoccq46j7 :ebroken down into colors asig;w4z8-zer*z6)5 c j:y r j jso7quac it is by a prism. Explain.

For both converging and diverging 3cim yxx pfy w54pdsa 633z83ulenses, discuss how the focal length for red ligm 3ip p35s8c3yx6 d4x3wf yzauht differs from that for violet light.

A ray of light is refracted throug 5+ngde7f6 4hz rug1pxh three different materials (Fig. 24–55). Rank the materials according to their51np4z7ghef x g+u 6rd index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source throug8j*sb wdg8y*c u o1zx1h a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern8bjz x1 1csoyw*ud*8 g that you see.

What happens to the diffraction huhs) .g* ljnoxn ua4ng c0*:f45j0urpattern of a single slit if the whole apparatus is immersed in (a) water, (b) a va0xu clf ao4* snh4*j0nu.ghn5 :u)jr gcuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (a) the slit 5scd*o 4(nl7tt 1 ndqxwidt(oncn q 1t5* d4sld7txh, and (b) the wavelength?

What is the difference in the interference patterns formedzwbgski 0z 5 33epqr(5 (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 (ac4 kagxz 0q(ihglc6d +:f/6zq) many slits, (b) closely sp6 :dag/q xhcgzk4(+6q0 lizcfaced slits?

White light strikes (a) a diffrac pw6af-oo9l(3d r7zxk tion grating, and (b) a prism. A rainbow appears on a wall just below t7z df- a oo9xl(6w3rkphe 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 wavelengths between 400 nm and 700 nm, incident normallyh9fhxn6gc x; im-2/fn 0yk;ed on a diffraction graffi m; yh;g nx90x/h-ndc2k e6ting, 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 so :3koj6+luvx;1x7v ;i7xdm*rymal zw ap bubble and not for a thick piece o ;u16j+v m*7omyr l3ai v:kxx;7dzl wxf glass, say?

When a compact disk (CD) is held at an angle in white light, the reflect:l3htufa d5l 5+sieb9on+ a8 qlc-uy ,ng6 y7hed light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic ltl: n+dhb 7fh+ul n ua-5qio69lc5y8a 3 ,ysgeight was used?

Why are Newton’s rings (Fig. 24–31) closer togethev w1ughg3,6mdj n(ez1c8. hqk zd1 f.lr farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What e. 2f7; dknbx:oz,iuawavelengths do you suppose the coating ike:a.xb7 zin2fd ;o ,us designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness 2 uh527e nbqzjis much lessn7h52e 2zjub q 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 naxsr(*wxld92l)f5w +bsyi- oe1 . sfbwture of light?

Explain the advantage of gl.q*;ofzol52 8yx96 n6bvhj n klgg5polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair ttz iotw- rj dg0 n;:6.f.ok1gof sunglasses is polarizing or not?

Two polarized sheets rotated at an angle of (lqri .)g,:ej2+ 1blgkr q zku90$^{\circ}\,$ 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 c;z8c*2vwg hxk+ d5gb9oul7 qEarth had no atmosphere?

If the Earth’s atmosphere were 50 times ds5-nsia.p5+w7-f uxr m fpjcrv 92r5genser than it is, would sunlight still be white,n+7xc2p mv5r-urp9f 5ag.ss-5jfirw or would it be some other color?

  Monochromatic light falling on gnq gm/ k9f:f.4 gzl,xtwo slits 0.016 mm apart produces the fifth-order fringe at fg:4mgf/q9nxlz.gk ,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 observed at an angle ; *png ps9r mf:hv9m-ohmr3x:of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two ver npbt t ;3kgf+u;u6s-1z/iaxr y narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the cenft3+/iu; n - p6zux1tks bg;rater of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne lase.+ n.zwm ; 8xxah,nl1ljl8 pylr, with a wavelength 656 nm, falls on two very 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?l;l1nl .j,. lyahnx wzxpm+88    cm

  Light of wavelength 680 nm falls on two slits and produces an interference iz:8doj 2h8 xopattern in which the fourth-order fringe is 38 mm from the central fringe on a sco:2 x8dhz8 jioreen 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 a:xdenqff w 56oa bq0kqoi7k 9 8;n..zypart, how far apart are the second-order fringes for these two wavelen7dqfnyq9wobx;.k5 n. kaqzo08e 6fi:gths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavg5o/m jtenj 15elength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at the same lj gje/o5m5nt1 ocation?    nm

Water waves having parallel crests 2.5 cm apart pass throw,w(fejcapm6- e(cr,u0jp f6ugh 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-throf0jmpww, ,6frucaec(pe - 6j(ugh” direction would there be little or no wave action?

Suppose a thin piece t *kj) r5c xrb0u3.fquof glass is placed in front of the lower slit in Fig. 24–7 so that the two wavesrqu.0fcr kjt )5x*u3b 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 ft:)fyqsczq,l sm8zd(+gj25, pu2gmt or light of wavelength 500 nm is located 12dl,2mgs,2 su5f+:cz( )tt j8ymg qzpq 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 from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm ar aanyss 5gx9y6:l*iy .e illuminated by 544 nm light. Find the distance between adjacent bl9sgsy 6an ya*:5. iyxright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls onscl(y 4b w:(hcswc;o, 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 apparatusg3bw4 mx4qy(g/ .egkx v1rf, e illuminated by 640-nm l yg.(1xx qee3rg w,g4b/mvk f4ight. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximat-d2y o y relgiav72 +vtcd:dq48:o,xt ely, does the speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fo dvgc74 dralt t:,yyi+o :vdq 22-8xeig. 24–14.)    %

  A light beam strikes a piece of glass at az1 lyoy5fp91tc 4itr)h xl8s1 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 x)0 7sq*ifq/e)wxqqk 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 0.044u/ lj8g*me. zt2wpm;g-( w9 orgks fk20 mm wide, what is the full angular width of the central diffractio p tww/f8l(grmjke. 2;u *mgks o-z9g2n peak?    $^{\circ}\,$

  Monochromatic light falls on a slit thael0.7 f3vkfk et 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 iswus 67 w bqn:vulqa/3n9iea.r/tk.e * $ 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 illuminaffkww g/g)g5- ted by 450-nm light. What is the width of the central maximum (in cm) in the diffg)f /wgk-gf5 wraction pattern on a screen 5.0 m away?    cm

  Monochromatic light nl awlj g-ac..f64+ jiof wavelength 653 nm falls on a slit. If the angle between the first bright fringes on either side of 6a.+wlij-njfa4.g clthe central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m behind a 0.0348hya7 8 io,lxo(i7r n0a-mm-wide slit illumhro ,yaxi7a l08i7n (oinated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a singf xaqb(nttu4m3c5 3p5le slit, the first dark bands on either side of cente3t5cmf 4t5n3buaq( pxr are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength ;nu5bhq3nu n / wol8j5.vu3 nr415 nm falls on a single slit, it creates a centra3;5hvn r8 .ujq3l nwo/bnnuu5l 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 d0 yh+ ;o6gzixriffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will6g +o r;yix0zh be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength dn qhj8k/y4eq8 pa24b*rfv e9$\lambda$, 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 maximt84rb wfxr *.fum when falling on a grating whose slits .f*tx fr8wb 4rare $1.45 \times10^{-3 }\;cm$ 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 centi1bpxkk zno489, gm*-w iu :flwmeter does a grating have if the third-order occurs at an 11k4l*kpx o 8n b,i:fwm9w-gzu8.0$^{\circ}\,$ 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 falleegam* k)ga ab.z0kr7)z qum43mxw 59ing on a diffraction grating is observed w7au*)qgg3 0k k)5azmazbmxem9 4. erat a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingbz oa43kbv; d (3zyms theh68y6-9vyw 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 normal nu z9uvip(azto3*(+gly 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 spectral order that can be seen if a grating with 6008ub;dk4qvbaf.:8 zajw sq2k; s.l q6q0 lines per cm is illuminated with 633-nm laser ligs 8q2 j zb.a8b;aqkwd vf:l.uqskq 4;6ht? Assume normal incidence.   

  Two (and only two) full sp5qx*)z bdzr/8a my8g oectral orders can be seen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the grad8zq8x o ba) 5m/zgr*yting?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410.xnie3gj +zolq9(3u y)a qwh+ nm to 750 nm falls on a grating with qxgo+j+ nla9qh3 ewy.()uz3i $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatn v7t trx8n*a5ne)o6gic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum lines are measured by a *ef cmp,gfy,1$9500-line/cm$ 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 waveb ;fcz.be6 kymt)0u +ylength is most strongly reflected at the ce bm.)kz;60ycu+efbtynter 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 Examcs jr ra1 k6r/o*y:lee3,d i:vple 24–8 if the glass plates are each 26.5 cm long/ j, *k ai3ry1dvo cr:leres:6?    cm

  What is the smallest thicknej f)3d3/h acunnkk.zs +l 7.uwss 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 yellowl )zi+uzpnu omv+k:l9o g ,65mu-)hnn ($\lambda\;=\;570\;mm$ 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 Newtonlf1n k3vn vvn +v7)ux8’s rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glavvvnux78kv n3+ nl )1fss 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 g u( nx *lcol-edw48;k hccy:u4lass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are obcc *-xuc4klyw; oh8e 4(nd :ulserved (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat glass suo7(*u 5e ji 2.ow89wz.gu, b4gnkke yc)mraodrfaces if the glass is to appear bright when 450-nm light is i5g mjo7ew2uw .uba) 9gord,z i cnk.y (8e*k4oncident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a st;po3 ypf6 kns2olen 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 alcohog yx)b6ktf3i q3n k;ap )lo6t(l $(n=1.36)$ 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 liquid, the smpl df ;(s)((ws5. (bemj swadiameter of the eighth dark ring decreases from 2.(fj.p;em) 5wb (sdwam(sls s (92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelengfn(c j cg ,dokkr)dhdq.;mu/* a81xh )th of the light entering an interferometer if 644 bright fringes are counted w) hc1*xu)mn ao q;dr jddk8(fgc ./,hkhen the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. Whe i1itw*)j,fni5-b utfn the micrometer is tightened down on a thin metal foil, 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 ntitb-,ii* wju5n)1 ffm.    $\mu m$

  How far must the mirro 6cevi -7s 0ugslvv *cmab.;b,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 (Fg6ow fjprv*fwll () :*ig. 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 lin6ljp)fr:l( gwo *wfv*e. 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 oriente0j ba5 806 a6tsacxbyed at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anles1iz53x)(2y hucot3bg p.j epgn06f,a3y tgle for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerg. l2mwpfo 39dgn7 ifh;ed in water if the light is hitting t73 d nm;9lg hfoiw.f2phe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are al/7se.q m(7 2exbcbubc//n moh igned so that the light passing through them is a maximum. At what angle should one of them m.(/ en/q h27cbbbu/xmsoce7 be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be pyqg1c nkx5*i3 laced so as to reduce the intensity oy q5c1ni3 xgk*f the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at 4jouv+ txmca; (cjq* *,0$^{\circ}\,$ 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 ori0)af7w sky7u 03cmg u+8waphsc lmu -/ented 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 r 9/.o h )6rml lzkjvbygf:y3dc2i+4mumj c5,peflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s an mr4hy kmu .9jbcgd+ l3/2fp:lyi)jzo6cvm5 ,gle 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 successive Polaro2q je c7hg)v2cid sheets, each of whose axcve jc7gh2 2q)is makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength c,c n:5v+mpy1wwtt g8 $ 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 airplanes27ofn yyv eu;7 can interfere with the direct signal from the statiof2ov7y e nu7;yn.
(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 s6 7unzlikax :5eparate sources passes through a diffraction grating with a7z5 lknu6:ix$ 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 narrogb1ox gx4ne .-w 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 unknowb ex4n-xg1.gon light? $\lambda_2$    nm

A radio station operating at 102.1 Mjb9wv) 74u hby(r9 bs xr1n)leHz broadcasts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. I4b br9h el j(9ur))v7s w1ynxbf 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 doorway 0.88 m wide, an) gy-v rqh4af23bhq8vd blows a whistle of frequency 750 Hz. Ignoring refl h4-q)rbahy2 v qfvg83ections, 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 semn)+7txffm e3nq, 8.u*cb-msl7 rc hlit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across them. Whenbkz+v2q m:rh. nor2 .m: hvkbzq+rmally incident 460-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 exblj0v mxz85 u+r9(i9d,byia grating have if there is to be no second-order spectrum for any vej0l +drxvubi5 8b x9mz9 i,y(isible wavelength?   $ lines/cm$

Show that the second- an8o9ez9omwqtm 7pfs o2 k7 3l:-9wjmyad third-order spectra of white light produced by a diffraction grating always overlap. Wha -sj8mo3oz2fta9e9wopw79 my:ql7 mkt wavelengths overlap exactly?

  When yellow sodium l4fi,4o 8a7nus u*rsqmight, $\lambda\;=\;$ 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 gratqzvp,/oe l 8(wing with and the pattern is viewed on a screen 2.5 m from the grating. The ,qle pz(/wo8v 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 ;1dv8nzk gfudwd clm(yg*b sbg3 fy.zp5 .- -,clear material if a minimum of 150 nm thickness of *klgu3.(1gnd.58w fzpsyg-bf cdm ;y-bzd,v 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..1hi;nravqepcbrp5jg;x+ xl g:a+ .z6tj(o wavelength is incident normally on a thin sheet of plastic film in air. The reflected l+5r.in.+ aeh px ;j6bo xgjl1qa. (g;:tvzr cpight 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 br9:4:ap8 0vfpmjfyythickness 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 flnq8 5rlqq +p6st (g g:wv/wil*ke s/x7at glass surfaces if the glass is to appear dark when 640-nm light iq vl/pk+qenrlx8ws s6gqt5/g 7(w*: is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layered on ;rz oujo(:j*1hfm :yha flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible value:zh hf*o uj1j(;:ryoms 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 hor8 l9u7fgai6 00xmsuc zizon is the Sun when light reflecting off a smooth lake is polarized most stroi0 ugf8amu7s0 9lzxc 6ngly?    $^{\circ}\,$

  At what angle should the axes of two Polaroida4v8d: jl3t)gwrmx i1s be placed so as to reduce the intensity of the incident unpolarized light dgwv4x8il:)mrta1 j 3by 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 whose transmv2(c: tsdd8zkdb.e2+sp p 0oqs -m8kbission axes are at right angles. A third polarizer is placed between the fs2(08dmtk8dbcsqv2p b sk d zo.: +-peirst 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 tnnx -z,i56*uvd b1y ogheir 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 slitn g xwgz:n8(os pmq2haj86l5: of width 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 width of the beam when it reachsqm5 z g868pogj2wx na lh::(nes the Moon.    km

  A series of polarizers are each placed athq *0ky nqc*x 0;onmr1 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 s2g apgciw74(ngr* 9 95mu8;o +fiav-m fidat$(n=1.34)$ 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 radiatfs5wi(h.fq(-w/(6t zl t2,pze p lra ling 6.0-MHz radio waves in phase with each other. They are located at pointz(r.t w(h p,q-eat52if6ls p /fzl(wls $S_1$ 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 lig*a o*+b a a.o,ukqhi,yht containing two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism (Fig. 24oa* h ,a.buyqio,+*ak –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 and one wi m4 6sbek:d;sc1qwzjeiijima*a z:52p(,x /hth $R\;=\;18.4\,cm$ 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