Does Huygens’ principle apply to sounn zn ,pc9xa+7pd waves? To water waves? Explain.

What is the evidence that ligh() m9 .k; 3dfbzm i,pnmabbii(t is energy?

Why is light sometimes described as rays and ymma(li6h-lq h 06/nn(m :qqo sometimes as waves?

We can hear sounds around corners, but we cannw * joqf25s:ifot see around corners; yet both soji f:q s*f5ow2und and light are waves. Explain the difference.

If Young’s double-slit experiment were submerged in hib 2:utn0/oa/;fmqnwater, how would the fringe po qh2m /n;/:0iftn abuattern be changed?

Monochromatic red light is incident on a double slit, and the interference - da e2x,sa,:)k ;i2 tvzy1ju rp7cinfpattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.:7 ycxp1,isf ,k aevaz2i2nuj;-rtd )

Two rays of light from the saodmw(t+t 8- )vys6wulme source destructively interfere if their path lengths differ bytv)wto+6wu-y( sm 8dl how much?

Why was the observation of the double-slit interference pattern mc;kxn glv52+r*elf x:ore convincing evidence for the wave theory of l2 xke gr5*+c;x:lvfnlight than the observation of diffraction?

Compare a double-slit experimee .t ,ftfp9o4vnt for sound waves to that for light waves. Discuss the similarf,4.vteo ptf 9ities and differences.

Why doesn’t the light from the two headlighi:1 gyh.21t jt qgg7kyts of a distant car produce an interferencehgqty. yj g1:tgk2 7i1 pattern?

Suppose white light falls on the two slits of Fig. 24–7, but ;u wsl5+tj 9ipone slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the patternw;9up5 ils+jt on the screen.

When white light passes through a f835rbbp. f06pj k6 n6pbfe-g s w7ehmslat piece of window glass, it is not broken down kpp3s-pr76 bn fh8js0bebwe 66f.g5m into colors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the 5h jk7yo f4t5h pulkw,)(ymey5d fd:1focal length for red light differs from that for (:eh,fk5 h 7yd)5fj w4uytp5 yko d1lmviolet light.

A ray of light is refracted through6n .q-jbu nbo/qin: (a three different materials (Fig. 24–55). Rank the materials according to their index of refraction, least to greatqn:qb jba-u( n/ 6o.niest.

Hold one hand close to youug(oe z5es) rd: ld cr-+cog/3r eye and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describeoguzrrg d+sec(c-d3l o/ e5 :) the pattern that you see.

What happens to the diffraction pattern of a single slit if the whmtmt9vegyyd)(g 1;ko jj+u 0rz.g0f* ole apparatus is immersed in (a) water, (b) a vacuum, instead of in ai;f* .1g +ody rm mjg(eu)tgkzv09t0j yr.

For diffraction by a single slit, what iu5o;k u ,mx: pa7yhkhvser,(ea* uq:9 s the effect of increasing (a) the slit width, and (b) the wave;s v ehy7ah,o xu:,5aepm*k 9uqrk :u(length?

What is the difference in the interference patterns for fb1w;mw;gph4z3c (1nvhk e*k med (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 (6qrdla +-jx,qb3wk96 w: hgrr a) many slits, (b) closely a9r6qk lq3r6rgw,bx jdh:w- +spaced slits?

White light strikes (a) a diffraction grating, and (b) a prism. A ra4e :r+)-4n xjkq;uocsto psvpum1+z1inbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the touoz)ep 4+;vst+ x1 c q14rsu-pj okn:mp of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incidenttpa m1(cbu0hbh04i)jmpg sd w;gphdx:9) ;2s normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answers h94 pbgi;p bj0); 0usx(p g) dt2whamh1dcm: depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a soap.0 1tx hymfcj9yft *(o bubble and not for yt0c m1*( t9oy .jhfxfa thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the refe-f 2cesl 0s;ksis(b (v);ctp lected light is a full speblssccf;v)esp ik2 (-e (;s0t ctrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) xw) 5bnq6zgr 9closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What ke sn8)(wss9swavelengths do you suppose the coatns)8 wk s(ses9ing is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness is w26 c1ws8i2 h/stn:y p5 cmfsxd3xi. tmuch less than the wavelengths of visible light. What can you say about the index of refm:t2f s 8 y3wics /1cxinh 52dws.t6pxraction of the oil?

What does polarization tell us about the na6on h(dd0psf9r8as, a2ciq 3zture of light?

Explain the advantage of pola (q3 pw afakx6v(5sm /;,ioex)m+ywfqrized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses i oqyw)dji a6v x *33s:;j9qlsls polarizing or not?

Two polarized sheets r.s ybv9krwx+2 otated 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 t9mp17vy.yrue )m8b q fhe sky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times dent r;hdx2o42c rser than it is, would sunlight still be white, or crr2; 4xt o2dhwould it be some other color?

  Monochromatic light falling ono p(ilrwn *r3v.,k d)x two slits 0.016 mm apart produces the fifth-order frwvr d x(ipk). 3,r*nolinge at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at an an2xh u(. wgncbfvf(*7 )2p( pcjhsana :gle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two very narrow slits 0.048 mm apart. Successive ota7j x. a02slpv7 cr6f+: dtlfringes on a screen 5.00 m away are 6.5 cm apart near the center olta7x.0d7pv6 ja tl+c:or2f sf the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of ligtm-:0fb1; ng 1 omjmwmht from a He-Ne laser, 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?1 ob;nj:mg0w 1mtfmm-    cm

  Light of wavelength 680 nm falls on f8 8t 5je1czwytwo slits and produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m awa 81wcy8zet5fj y. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.5888z1ketz54(5j fz60gmexqce1 kxvv o mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 m away? ee0 ovzmtz86j48c1x1q gf(ez 5k5x vk   mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nm g+ydmhlec .0zhp-m e:+wy,,6 gp w bub r6pe0w,ives a second-order maximum at a certain location on the screen. What wavelength of visibl:m,bpup+wzmgcprw0e6 ly+ hy -de0.h w,6be,e light would have a minimum at the same location?    nm

Water waves having pa(-v t8qd gmm7, dvyqj.rallel crests 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the boarmqg, vmjv. d q(78y-dtd, at what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front0rtmnj-1 nhy 3 of the lower slit in Fig. 24–7 so that the two waves enter the slit3ht 1-mjnyr0 ns 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 for7- o11vjyt shjctu +k2 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 far from the j-o1t7kjtcu s yhv1+2central 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 -+i;vnlv*-/x l1p + v ,dymha3+8tkmaoyuoconm light. Find the distan p*m;u-o,y- al/y8v kio+a+h+do lcvn mt x13vce between adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two sli-jrp3 du 8lq7rts $6.00 \times10^{-2 }\;mm$ 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=1.60pg(h0* t p3lffrkh+)k ) covers one slit of a double-slit apparatus illuminated by 640-nm light. The cent frfpl3*hp(g0)hk k +ter point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speeg9g bap vk vu2r(dm ,j,7z5,jyd of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glassm ,zrj7pyg9k 5(,,j2vvgudb a ? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass 8laegy qos0j+geizpos w+i5.49x ,v* 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 contain y za ycjnni12vx3+;,p-wat)pm5 aiz)ing two wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm widvhhd1dl2-a (c e, what is the full angular width of the central diffraction pea-lh2 1chadv(d k?    $^{\circ}\,$

  Monochromatic light falls onc p,3urm 9ehls- sx76h a slit that 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 ip()z00fgf gi8f9 zh vms $ 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 byl a8tyh:l-ep02tw/zm su /9ux 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a scr/ 0t9/hxlw -tluepa82 my:suzeen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angle bet;dz5xvynx+ v+v sa :yt6ms 6a6ween the first bright fringes on either side of the central maximum is 32 n:;a6v zx+mxs6t+v a5v6s ydy$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffrahn: f*vmxkp8 4,jt-naction peak on a screen 2.30 m behind a 0.0348-mm-wide slp 4a n-mht:j x,*nfkv8it illuminated by 589-nm light?    cm

  When blue light of wavelength le4zbj3y/.d e 3 8luhr440 nm falls on a single slit, the first dark bands on eitz 4lehdurl8b y3e3/j.her 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 on a singleuv ao4l :ywa(0 denu6+ slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the sl0lau4 na6 w(:o+dvuye it?    mm

  If a slit diffracts 650-nm li+2ebwew,fd+kd3/ ; ie l.csekght so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m w/2 ;d.sf +c e,leebd3ek+iwkaway, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengthd *cdu 06wv2*j6++ nlj.;siepjabg mm $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-order maximum whei d embtq200y*n falling on a grating whose sle 2yi* m0qbtd0its 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 cklhdc/63c l 0ventimeter does a grating have if the third-order occurs at an 1dlhvc 0/kc 3l68.0$^{\circ}\,$ 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 fuf, ho t4i;p-light falling on a diffraction grating is observeh foft-4up;i ,d at 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 has gofnt((wu-*y:,x fdpla6 z v0 $ 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 .qa /fh4e 92 woowmpc($9700-line/cm$ 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 s:0+vwg+rk2phg w *g7 i4f)x 1zpfgt jppectral order that can be seen if a grating with 6000 lines per cm is illuminated withxpffhg1 gtwv0+2:z r7ikwg p+p* 4jg) 633-nm laser light? Assume normal incidence.   

  Two (and only two) fullf(bx;s wnf z3 ig;bm72 spectral orders can be seen on either side of the central maximum when white light is sent through a diffraction grating. What isgs;n imw;fxbf 73 (2zb the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths fxbspq6ade( v / r*.vjx6l0y+orom 410 nm to 750 nm falls on a grating with r/xlv. p6(6j aq*ysx+bde0ov $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromat5s x)+gw*) lgzwmx cdz b7,rlm7a; ab5aom1)qic 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 lin14 rndcm7 +hhmes 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 wavelengq tn8j; 9i f7zytpph/2th is most strongly reflected at the center of the outer sur pj2nzyft q/ip8; t9h7face when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the darkje wv; o9;l3:i qaui7l fringes in Example 24–8 if the glass plates are each 26.5 cm lo7eul q9wii; :j;alvo3ng?    cm

  What is the smallest thickness of a sxipgz 0cx c; jgb2u3.-oap 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; t z7gvx:ebl oy/.u4h yellow ($\lambda\;=\;570\;mm$ 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 N+, g+*xu rwricuh*bpjko(c 8-ewton’s rings (not counting the dark spot at the center) are observed whroxric jp-w ug+hbc+k** ,u8( en 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 piechl i mpr.;.lwq u;x7i9es 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 tmruwqh7; .llx.iip9 ;hick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat g21n x.l4vt swllass surfaces if the glass is to appear bright when 450-nm light is incident normally? sv2x1.llnt 4 w   nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stol jdh:x9e+ drhr5mwnheg3c8 6k4 py6 *cen 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 alcoholehqo1b w- +gkuw3m61b $(n=1.36)$ 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) i adaz,myxe d-,:h)cqd 9w7ff3:a 0ok ms immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refrazkao,y- 0h:em ) 7,wd9f:cmf 3 qaaxddctive index of the liquid?   

  What is the wavelength of8uhjng-mmu 1 d2b eb+- the light entering an interferometer if 644 bright fringes are counted when the movable mirror moves 0.2huu8j+ b1-2-ebmm ngd 25 mm?    nm

  A micrometer is connected to the movable mirror of az xheo a5ld 19:yf9o:pn interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer, izyda o959p::x hf1elos 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror hm4 k*hx/jw v f*du-z2$M_1$ in a Michelson interferometer be moved if 850 fringes of 589-nm light are to pass by a reference line?    mm

  One of the beams of an interferometer (Fig. 24–59) passes throudi(3rjg*n)op,wb4fb kc (b7v gh a small glass container containing a cavity 1.30 cm deep. ((b jr gfp cvnob,43dkbi7)w* When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orientej,*df2uyonwu c l-j.-f/c gw8d 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–gx.e7gd nn s2io*i,6qplass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submexfjps3 p2 pvag*/s p(.rged in water if the light is hitting tpx*. sasv 3pj(/2f ppghe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the liz f2 mu6u0bf w3aef9i(9vy*zught passing through them is a maximum. At what angle should one of them be placed so that the izbze3uff*v 929 (ufu0 ymawi6ntensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed znzq -4-d, zjf o pqchemxjq04,:d/zf,7 1bev so as to reduce the intensity of the incident unpolarized light to z-o7 1qej,z,:mcf/eh4 zpfqvd - dn4jxz ,0qb
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are o76p w98bx: n v9dgznpbriented 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 oriencw:buc fmc 456ted 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’stw s wo9vbb0wbh+n06hgb1 4z 4 angle be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewstetv0b+0 bhhgo6b4wb41 zwns w9 r’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 successive Polaroid sh//z-aaai(z6 h/l-uzq cx.n,rigd6 b ceets, each of whose axisb --n zd./zza6ilc/gci6, (hqxau r a/ makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength fm3;hjd;nz e8$ 5.0\times10^{7 }\;m$ passes through two parallel slits and falls on a screen 4.0 m away. Adjacent bright bands of the interference pattern are 2.0 cm apart.
(a) Find the distance between the slits.    mm
(b) The same two slits are next illuminated by light of a different wavelength, and the fifth-order minimum for this light occurs at the same point on the screen as the fourth-order minimum for the previous light. What is the wavelength of the second source of light? $\lambda_2$    $ \times10^{-7 }\;m$

  Television and radio waves reflecting from mountains or airplanes can xamjb:)a ,q4t l9i7lkinterfere with the direct sign ji9:xl ,bk 7al4amqt)al 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 t-t;ys q: rg-)m 7iouc.cpe) hkl1s e-qhrough a diffraction grating with .:7yq sriqe e;s-u)-c -)cthogml1 pk$ 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 narroimd1nf0oc :n: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 i0fico1m nd:n: s the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two iden* z,d5bb4 8tx6m4nkzvv dpf8atical 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.dv5dzv xpfbkbzn 448t68*,am 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 outsid+7x -,euqqfbx e doorway 0.88 m wide, and blows a whistle, b+7-euxfqxq of frequency 750 Hz. Ignoring 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 ouddp4n5yj 13)liyi6w n a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of 9j5j0r 9ef+y gl8b xsbparallel lines across them. When normal85g+ yjj esbl9b 09xrfly 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 centimool-vrp 44s7f4kfg.x eter must a grating have if there is to be no second-order spectrum for any visible wavelength? .p-fksgvr7 lfo 4 o4x4  $ lines/cm$

Show that the second- and third-order spectra of white light produced by xv4mv9*8jx pg a diffraction grating always overlap. What v *m94xx8j vpgwavelengths overlap exactly?

  When yellow sodium l a)k*pdph.j7b f+o5ifight, $\lambda\;=\;$ 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 an6uj q5;f h4dfd7zx l7ad the pattern is viewed on a screen 2.5 fu flxd547qj;d ha6 7zm from the grating. The incident light beam consists of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clea:vf- urk dxwv (s+/:rxr material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normsru v dx/ r-v::(k+wfxally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is inciauq8 )g o7vdps0.6t izdent normally on a thin sheet of plastic film in air. The reflo07)u gqitpd v.86zasected 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 cy1:r5 r64 qe upoug(rjoating $(n=1.38)$ 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 xlc: h.,mzt:l* mv)) edyyzvry20a 8uflat glass surfaces if the glass is to apdl :ye2r.z v,atyhu80)m l)x:cmyz *v pear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the ligh0kdwmer0yy kjha)w,w,)wz .8h4+0dwxsb a6 vt transmitted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the cone)axd.rywhm s0,wy+ 0,zkha vkwdw8)w0 46jb ditions 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 Sun uopk)6. 6vegni sqg )(when light reflecting off a smooth lake is polarized mov(qkn i g)e)6 6usgpo.st strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to re3/ary xr)j6 fvduce the intensity of the incident unpolarized light by an additional factor (afterx/3j )r6va fyr 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 transmission axes are at r *xcdco*iq)tfo00 ycc.6x/h g ight angles. A third polarizer is placed between the first two i*0hc t)gxycoo 6c.fq0xcd */so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axes -hr g(juns d-b 08mazr)x8)fs 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 wd6owv /(wxg -didth 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from txdo w6-g(v dw/he 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 reaches the Moon.    km

  A series of polarizers are 2gewdl 0bn,rv .e-fj5 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 gcqv r0t 54/ dz*.kiwb, 7ewsmfym:2qe9,t qz$(n=1.34)$ 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 f7ya)aio 7, xq0vwr-qn9b5s a radio waves in phase with each other. They are located yns ,owi)fbaxr q9v577-qa0a at points $S_1$ and $S_2$, separated by a distance $d\;=\;175m$, Fig. 24–61. What are the first three points on the y axis where there will be destructive interference? (Destructive interference in this case means that a radio receiver placed at that point would pick up no signal).    m    m    m

  A parallel beam of light containing two wavelengths, 420 nm and 650 nm, ente:mx 8x1f:ax5wcse. zgr-k j2wrs a silicater 1 jex :5:smk-.xxgacwfw2z 8 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 surfach/*v ltfgoxn,1wu6q r (kiu/ flmq810e 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