Does Huygens’ principle apply to s . j5siel+nas/ound waves? To water waves? Explain.

What is the evidence tj 8, 0eexqvt:jxl ,h13 ul3 dj7.gidmdhat light is energy?

Why is light sometimes described as rays andvm8-w b3uo)v p sometimes as waves?

We can hear sounds arounv9.xmb/ d( fwcd corners, but we cannot see around corners; yet both sound and ligxm9v/(b f. cwdht are waves. Explain the difference.

If Young’s double-slit experiment were submerged moc-in)01p; )ai ejsiin water, how would the fringe pattern be cha)s)em-ji;1in ciao 0p nged?

Monochromatic red light is incident on a double slit, and the interference 54, 84xy4gl2ahb( i as 3)w+m r0veessrqfbvdpattern is viewed on a screen some dl50xd4 bs)a m(i+ avrhq4ef we s3s8r4,2vgbyistance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light fr1rxkvp)hr:ia l 3yg5n2q6+k mom the same source destructively interfere if their path lengths differ by how igv3pyxq2 5l:1ak+ 6h mk rr)nmuch?

Why was the observatiowaeukzwb53 wi05 y0:q jl (3svn of the double-slit interference pattern more convincing evidence for the wave theo0kwszyuv(55q3a3lbw i0:w e j ry of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that fszb4a):ypb23 5ffe5wxd 2 xze or light waves. Discuss the similarities and52wp5b zd 2eax 4:bse)z3xfyf differences.

Why doesn’t the light from the two headlights of a distant car prw+yi j-3md6e b 77:cex- ofkvroduce an interferk mxdrjvy -o77 6c +ewbfe3:i-ence pattern?

Suppose white light rr p2ak w8h9.jfalls on the two slits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm 2r.ja8rw hk9p). Describe the pattern on the screen.

When white light passes through 3d x6v*h,x*yaw*e bhu 3xdu( fa flat piece of window glass, it is not broken down in6ub*(h dhawxf yd*, xu3*3vxe to colors as it is by a prism. Explain.

For both converging and di evh .(rbo7 (vax3ozd. ov4-mvverging lenses, discuss how the focal length for red light 4.3ozemh.v bvro(v7- x oad(vdiffers from that for violet light.

A ray of light is refracted through three different materials3sg;uied1 5 tbugn3f + (Fig. 24–55). Rank the materials according to their index of refraction, least to great 1b;id3nuu+gge5 3sftest.

Hold one hand close to your eye and focus on a distant light source rxf9kc-w;f7 bthrough a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern txf ;w-bfk7rc9hat you see.

What happens to the dif ec4b26kwi 5y /vqk7ghfraction pattern of a single slit if the whole apparatus is immersed iv5q2b/7e6ckw yk 4igh n (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect oam .n /94jlkusf increasing (a) the slit width, and (b) the wavsk u.n94/jm alelength?

What is the differenaleqi:h on) p1ixa; ogr1/),cce in the interference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, whai2 xydjo jeyw4 6-)n+/ehtbi5t is the advantage of (a) many slits, (b) closely spaced slits?d-/ 25+n 4)6e j iehybojiwtyx

White light strikes (a) a diffraction gratingvu r+sotp n tgohdb :3169up06, and (b) a prism. A rainbow appears on a wall just below the direction of the hopt1 v+3:u g6tbs06on p9h rudorizontal 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 o2n0c)cl,w lnrbok fp a a 8(rc:-1ua4nm and 700 nm, incident normally on a(crw1nallkcbo2na-c pa:r u4 ,08)fo diffraction 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 axbkf j ygfa3vk0-dxe 6(ol4(+ thin film like a soap bubble and not for a thick piece ov+(fa oldb3y0 xk(eg xk64-jff glass, say?

When a compact disk (CD) isygfq/)n 0bfv 2 held at an angle in white light, the reflected light is a full spectrum (Fig. 2bnqg2) yf/ vf04–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther fs l9c u)w63rhnrom the center?

Some coated lenses appear greenish y g 1 thl1s lbx915jlv7s,bf+mrellow when seen by reflected light. What wavelengths do you suppose the coating isf l,bx5 j91 71+rmvsl lhg1tsb designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where ilp(r; x tn11w05myrkcts thickness is much less than 1prm1c0yrw;txkl n 5(the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us about the natex gp ;h -)crfn3j,la2n29qbw ure of light?

Explain the advantage of polar e(b7 hcch4x46+qwai lized sunglasses over normal tinted sunglasses.

How can you tell if a paupey8z q3i58m k7(qolgycl 1f9; l*tdir of sunglasses is polarizing or not?

Two polarized sheets rotated at an angle of 5 ggr97 h0zg stx8z4mnw8sps090$^{\circ}\,$ 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 h73usb 8fnc+mt u77zqz ad no atmosphere?

If the Earth’s atmosphere were 50 timesj bxi/4e)e.02,/ dsxgpu emsf denser than it is, would sunlight still be white, or would it be some otheex.2,//bue dgxj4e)0s f msipr color?

  Monochromatic light fallj*67wpbpewvm+ 4(p+ c7 wsosfing on two slits 0.016 mm apart produces the fifth-order f+*pw(pw6f7 vb p7e4 owsjcs+mringe 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 angl.hdim1rk 1+ cpe 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 apab8 uzyhmo91 i8rt. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and1o98zu 8ymb hi frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a n ,op (+dm* vauk2-mamHe-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 ,m2+vm*p -nmkad ua(o center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 686dwfplit62mmz15 t)htp3l 5w0 nm falls on two 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 away. What is th1z f tw)2dmmp6pt6ltl 3wh i55e separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.585 jsb1 0 e5lslxo8yeq5 mm apart, how far apart are the second-order fringes for these two wavelenglxl5q5 8 oess1yjb0 5eths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found vxuf p.w w3;8zprdo+6that blue light of wavelength 460 nm gives a second-order maximum at a certain loc;d8pw36+x w.f orvupz ation on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests ejww96n*xfs cj)e/n6 0- z0im 5mfsgx2.5 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-throughj 5 /)6 9njiwwf6z0ef- sncm0*egxmxs” direction would there be little or no wave action?

Suppose a thin piece0y;s8qx(;b8lc4gd,y1o-rb 1 ebwsunnaf 4 w g of glass is placed in front of the lower slit in Fig. 24–7 so that th4y 0by s we;,gqfd;lra on1bc-(4g88 wnxsu1be two waves enter the slits 180$^{\circ}\,$ out of phase (Fig. 24–57). Describe in detail the interference pattern on the screen.
24-7
24-57

  In a double-slit experiment, the third-order maxkxw12n e.ec c:imum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. ke:wx.c 1e2nc 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 1.012+5 lr+pxfi8fekasa+ e yv a4 mm are illuminated by 544 nm light. Find the distance b ear1 +fi+e8 vp2lkxaa 5fys+4etween adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air fal2,mz b9gj so*-oz. sbuls 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) 9bj tm.suh3g: zmh(j )covers one slit of a double-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 thes 3jj( ztbg h9mm.:h)u plastic?    nm

  By what percent, approximately, does thesv:x;b+1sg -3l qypk m speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fig. 24–14.1p;x: qv+-3gbs smlyk )    %

  A light beam strikes a piece1 vg5 sz0yfhd- of 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 wavelengths,yrw y8r l2l0pi lsbv*bv+74whic26r 4 $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm wide, what is the full angular width -8stbqua11wj8z6 cpef-2q qvof the central diffrac abz16utcfqw2q sq 1-e8v jp8-tion peak?    $^{\circ}\,$

  Monochromatic light falls on a va6qxzq72w .w 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 fal- *jhu(dgoz;,ek, c rlls on a slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide is illuminated by 45l o m 1oxn-w(h,,qrh-k0-nm light. What is the width of the k x-qow hm1(,oh,nl-rcentral 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 betweebt-u(y klfc.p7 n5t*pn the first bright fringes on either side of the centy b7 n.ktt*pul-fp( 5cral maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffrachj xh).0q(rua*7lok4z a)rxotion peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm li.zkx7alu)oo *)r 4r0xh haqj(ght?    cm

  When blue light of wavelength 440 nm falls on a single slit, the firs +yz p 3(/mb jw5)pem3kv93bwacgz5 qdt dark bands on either side of w5evm qp3 b/wcm +5j(z3kzd by) a9g3pcenter 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 single slit, it creates 5gihb :gd fwz2x.,og6a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slwf:ixb g .d6o zhg2g,5it?    mm

  If a slit diffracts 650-nm light so that the diffra z-9eda0 ba szj *+thw 1.lnbuf*sf*u4ction maximum is 4.0 cm wide on a screen 1.50 m away, what wul1jubd*ba09**f a n fhs . tw+szez4-ill be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength ogv-vs/1o 9jh $\lambda$, 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 9;t/aztvohbg11 lq l7bw*htvigk.. 2 maximum when falling on a grating whose slits arl hzlt..k tv19viaq tb;2 *71bwghgo/e $1.45 \times10^{-3 }\;cm$ 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 do ,dsumcjy(vpgn: .2r7es a grating have if the third-order occurs at an cn7g, m2p (:sdr jy.vu18.0$^{\circ}\,$ 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 fallhm0 g5jz.y,b xn52r+5copcn6 8o luf0 bbqv3ping on a diffraction grating is observed at a 15m26+b px.v85 qpuzn5oc rjlo0f 50 hcyg ,nb3b.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratinq -czqrx ,**jir uh)ume)d;,b g 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 normall1eqp1o-m(ua dg.x603gy b gtpniyc 40y 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 spectrap(3uc fgxi ezb:rgh(9ab1 r5 ,l order that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal incipxcf heg:a ,3r1bu( 5brgz(9idence.   

  Two (and only two) full spectral ordeb113a+vaqxgp rs can be seen on either side of the central maxi+g a xbq3a11vpmum when white light 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 wavelengths7)bpthai rx 8z p2g64x from 410 nm to 750 nm falls on a grating with4 2xphai zt6px78 b)rg $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monoch81e geq wzu*nx .oz3i9romatic 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 spectrufoiw,c:0d 9iym 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/n,8 d,sgswfb wavelength is most strongly reflected at the center of the outer surface when illuminated normally by white light? Assume ,gfw/b d,s8s nthat $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in m1hzimi1; mzn3yo*q:Example 24–8 if the glass plates are each 26.5im ;3z1nm mhq yz1io*: cm long?    cm

  What is the smallest thickness of a soaiqt7 y,mm u./w/eg/ gap 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 yellow (f* flrm c95)x/:ntrl l$\lambda\;=\;570\;mm$ 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 the dark spotcxp q:k0 h vlq30+se*p 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 thicker is :k+l0*h cxvqp3 0peqsthe center than the edges?    $\mu m$

  A fine metal foil separates one end of twoq82)un2j hcyw pieces of optically flat glass, as in Fig. 24–33. When lighh 8j22u)ywnq ct of wavelength 670 nm is incident 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 between two9,fc7mp4bgs r4 r.xw5kw1bch flat glass surfaces if the glass is to appear bright when 450-nm light is incident nrmh xs5 4c ,b4fc7kwg1 wpb9r.ormally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of be,2ja34i4c )tvp tovf king 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 a j-)3cb,*gmu1fyc;5y zpal4 zrhr w 2$(n=1.36)$ 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. 6p5v (k n7za n 3e**zvd.rzszc24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.cz en ak5.zvz6*v zdpsnr7(*348 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 briu+uue v9te .4xght frieu.x+ut9e4u vnges are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an ixqof8qd ;5s(r di173.pn b)1 fvqx jy m(4oevonterferometer. When 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 thicknessxe( dj b5ff1 q( vns 7x1.o)ymqo3ovqrdi;48p of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirrod dc ,kguq/phb,;gevv l( nqei81392/a j1w bwr $M_1$ 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 through a small glu9 4 -j1-s)2phq q*bq*m xeuvmbpvbd)ass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fm4suqxbvh2 dv*q)e m1-pqbj -ub *9)pringes 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 oriencr y v4unm4.kmy2pz6mg 9t,o *ted 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 /b:8w g z.lkv)7o jjcym+1 qyeair–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is p1uws/9wn g9 xhitting the diamondn1w9wgs/ xu 9p $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that tha0 ir4d8)in lne light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequei0di8ln )4n arntly reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids 27,nc5dp/yrp pr6qn sbe placed so as to reduce the intensity of the incident unpolarized liqdpp5r7 6/2spnr, nc yght to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orierr lrew z,qod4d wfsr:v cx(13u;) 09mnted 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 oriented at 38-ull*l*hi- o h.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 fo4ea 2n.1o sjcrcg;6pgr light comincp4g aso g6;2jr. 1ecng from beneath the surface? Compare to the angle for total internal 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 througpj/dpu2,uq7vt .z ew 2h five successive Polaroid sheets, each of whose axis makeqz u7u jtwp.2ve2,p /ds a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 9j8 spwb iqz;8g;kq,kt hgz42$ 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 airplanw) iksf+ug+ 8les can interfere with the direct signal from t+k+)ifs ug 8wlhe 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 seo4i7k:eadh 25djy4tnjmok7u ( -c 9 mfparate sources passes through a diffraction grating with oj:dhfd n4mc oj a7em-uk i2ky(459t7$ 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 apa 9d0 rprca81fart. 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 tar1facprd8 09han the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts frrdm3i+tjn,p.yr t/2:d9 s1 ty cx 2zgcom two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal irxpct n/+3tst9,jmdzgr2i .yc :1 y2d s 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 doorway 0.88 m wide,. ta*hebwx5/y8p-,9x jyj clo and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not po5 xj8h 9ye./*wbpo,xlcyajt -ssible 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 o50w pwow(7*;+ w0tzdbjgdk )me iw.lpf width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a :irp, u.:oymo. e;q h3zdaoy/series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at ,oooy3ehz pi/mu;.ya d:r:.q an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must ajr/mb; inh)bs h4ii -: grating have if there is to be no second-order sp ;si mibhn/i:-b)r4jhectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra c)gx bsg3hc)0of white light produced by a diffractio) ch)x0gbc3g sn grating always overlap. What wavelengths overlap exactly?

  When yellow sodium lightrd1q: 0//onlf02f) sjgt 6mr zp+ubnz, $\lambda\;=\;$ 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 onv k:ljzz sf. fx(0;ll o*:kmm4 a diffraction grating with and the pattern is viewed on amo:( j:lslvffk4zk0;lxz * m. screen 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 refraction of a clear material if hbk h2)gx// soa 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 ig2k o/sb/hxh)ncident normally upon it? Do you have a choice for an answer?

  Monochromatic light of varkq2zzc 82bktp 3dc3z6iable wavelength is incident normally on a thin sheet of plastic film in air. The refl3qccb62k 3kz8dp t2zz ected 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-refl1wp6 n hnr-l;f.i v9m;l judh2ective 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) f22fry3wi hc9thickness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm light is incident w 9y3i r2hf2fcnormally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the(yscru 4au)8v light transmitted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and d)vsr4( 8uy aucescribe 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 oecma 7f4 x3vn(rf4i7oza pr6/ezh)u3snw -)Sun when light reflecting off a smooth lake is polarizedmac/r n4f ax)n oo3shzup7)6f- r 3ew e7ziv4( most strongly?    $^{\circ}\,$

  At what angle should the axes noi,*r +n;j u5 ajit*y:xbb *iedo6*aof two Polaroids be placed so as to reduce the intensity of the incident unpolarized li* axdn, i* u6 n*iaioj:ebor j;t5b*+yght by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on b).53odaeugf jx .j1eu5f)1cka gn5 ctwo polarizer sheets whose transmission axes are at right angles. A third polarizer is plac5cfx.)feduj )gne5 j.oa 1au1kg 3b5 ced between the first 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 wirdq/63yu49o oblwfvid 1 i o0to )2ze;th 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 t wktq,idua: 08hrough a slit of width 1.0 cm and is pointed at the Moon, which is approximately 388q,i:ka 0ut wd0,000 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 reaches the Moon.    km

  A series of polarizers5(j2uip8g zjt 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 jc uh-i).)r ec$(n=1.34)$ 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 radi-md 2shpa2 kerf)x70gating 6.0-MHz radio waves in phase with each other. They are located at pointshd2 g 70-a2ms)rpxk fe $S_1$ 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 lightj joo7:8me x 9x6u1jfv containing two wavelengths, 420 nm and 650 nm, enters a silicate flint glass 8j9vux f: ej1jmo7o6xequilateral 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 and one t)xf gd f4rfbip7e yo,n;q3--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