Does Huygens’ principle apply to sound waves? s/ltvq, f d4n-88j:tt gsu q:tTo water waves? Explain.

What is the evidence that light is5 skr0ygj+sq/cq5kh0d 8au3 v energy?

Why is light sometimes describv1 u1 kz6y.alz1n +bbxed as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see arounf2d:s g,4up fud corners; yet both sounugp2dfs 4f: u,d and light are waves. Explain the difference.

If Young’s double-slit expegd0q-j(ds2o d riment were submerged in water, how would the fringe pattern be chang0so d2g- ddj(qed?

Monochromatic red light is incident on a double slit, and the 0(qphvx5da+7mlq x:o4) jytkf1 yn z/interference pattern is viewed on a screen some distance away. Exy40joqy7f / )t1:p5l vzn+xqhd(amk xplain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere i9;c 07c hrqrar 9(wexd-dj*mhf their path lengths differ by how much*(r xrm70r;wqdehc-99hdcj a?

Why was the observation of the double-sliv/8rw tiz)m, z1jasb*t interference pattern more convincing evidence for the wave theory of light than the observation of di8j ,1sivz zt m/)ab*wrffraction?

Compare a double-slit experiment for sound waves to that for light waves. Discu crhzfh3i zu6tx2:a.7 ss the simi fh 7a3rt.uzihx62c:z larities and differences.

Why doesn’t the light from the two hey9 *sf;. ozmozs1+p cjadlights of a distant car produce an interference pat+op1. jmy cz o*z9ss;ftern?

Suppose white light falls on the two sle/lpbq jo 5/vsv5v7du9,3zlr its of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 n, d/ ovqvrlj5s9u p37v/ 5zeblm). Describe the pattern on the screen.

When white light passes through a flat piec( an x1/nslvg)e of window glass, it is not broken down into colorsnlxnsg) /v a1( as it is by a prism. Explain.

For both converging and diverging lenses, discussuya9v h/:u4j o how the focal length for red light differs from that for violet light.au/uy :jvo 49h

A ray of light is refracted through three different materials (Fig. rkp )spe a3lrf9j98 *k;x g3hl24–55). Rank the materials according to their index of refr)x sl99kjl p 3fr*a83peh; rgkaction, least to greatest.

Hold one hand close to your eye and focus on a distant light source throx8b c-6u:q.d0+ w usnpcdzic(ugh a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the:u spubiq.cdc 6zn+-( dxc08 w pattern that you see.

What happens to the dixd5/rz( kh lu,chkf3 5ffraction pattern of a single slit if the whole apparatus is immersed in (a) water, (b) a vacuum, inste5f , hdruz3/ clx(5khkad of in air.

For diffraction by a single slit, w7w4l -2mym(r(kjor m l n03+felwy5zkhat is the effect of increasing (a) the slit width, and (b) the wavelez 2lmwrm4 (neo 5k-yry 37mw (lfl0k+jngth?

What is the difference in the interference patterns formed (a) by two se.1 vz3p)8gay8hwwn s lits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the ar(f)k. dde;uiz1oi - cln,ef9 fgf77hdvantage of (a) many slits, (b) closely sp kc leof.(nzfghr )f ui9-;d1,de7fi7aced slits?

White light strikes (z*ij- )w l5nxta) a diffraction grating, 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 the tz*wi) -njl 5xtop of the rainbow in each case? Explain.

For light consisting of vc7g7-. cphxd wavelengths between 400 nm and 700 nm, incident normallych pc7-.dgvx7 on a 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 a thin film like a soapiy;du9h; 4ksm-7 japq bubble and not for a thick piece of glass, p4dy sauq;k9;mi-j h 7say?

When a compact disk (CD) is held at an angle in white light, the ro*+*oz) 85ssfco;ql ypj i;h yeflected light is a full spectrum (Fig. 24yjcsf o+sh5pz8*iy;l )q ;o*o–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 2411)l+)gi +ks ceec ced–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by bo yqy6d,x7*g k6 oggu-)r2cireflected light. What wavelengths do you suppose the coating is designed to transmit completelyrbdy2yg67 q ,*gx ogk oic-6)u?

A drop of oil on a pond appears bright at its edges, where itsumtm+r g 1c2z7pb-34 8bvrrgxxg :o g9 thickness is much less than the wavelengths 2xgrxg1tzc u7: 8o mb+rbm- 4pvrgg 93of visible light. What can you say about the index of refraction of the oil?

What does polarization tel *1cyfk fk2/rjmc sx*4l us about the nature of light?

Explain the advantage of polarized sunglasses over normal tinted sunglassbfc;d; 6g+k/5 cxfl jses.

How can you tell if a pair of sunglasses is polap2. +jb,mpgg 1 wtaxw g7r*h;lrizing or not?

Two polarized sheets rotai 8p l 6n.pos2u5hf oonj1gz.,ted at an angle of 90$^{\circ}\,$ with respect to each other will not let any light through. Three polarized sheets, each rotated at an angle of 45$^{\circ}\,$ with respect to each other, will let some light through. What will happen to unpolarized light if you align four polarized sheets, each rotated at an angle of 30$^{\circ}\,$ with respect to the one in front of it?

What would be the color of the sky if the Eah:l+he f rm0y c5;vq u,b1b3ywrth had no atmosphere?

If the Earth’s atmosphere were 50 times denser than it:(cdmkb u/ 7ln is, would sunlight still be white, or would it be some other cu /c( :nbld7mkolor?

  Monochromatic light w:uh/. 2bqu,,vtw g aifalling on two slits 0.016 mm apart produces the fifth-order fringevu,2,u/watq: g.bh wi at an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 61)nqg kq.d): xuj5p 9k7qz +iwz0 nm light is 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 slxmy2e2 op.y5w4lh ik1its 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelengt .keiw2ypxh45ly 2 1moh and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, witqztl cx7*ke /y* 1qay1.ngkp8o1as2kh a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the cenk8a s2*71*qylq/xt n ko1p azyck 1ge.ter of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm fa daxbp9(eoh umrj2 /ua2t l++c2 (k(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 the separation of the two slits2abdc ( 9(2 oahml/ +akr(f2xt+eujup?    mm

  If 720-nm and 660-nm light passes through two slits 0.a57lnbp ;.th uiuuw 8.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 .lnhup7.u;a 8ubt w5i m away?    mm

  In a double-slit experiment, it is found that blue light of ,bxc8lub;;ok z xl4 u1wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a mini;xb1l4ox;k8zc ,buulmum at the same location?    nm

Water waves having pa4(hx8c0.i u(jtmigrul jh fhit :j55 qa,:7 wurallel crests 2.5 cm apart pass through two openings 5.0 cm apart in a boarjc(h.j0ir(8:g,4w ltxt7 uufu : jq 5hai5ihmd. At a point 2.0 m beyond the board, 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 front of the lower slit in Fig. 24 ml ll2:vjuogz)fx7 6r0 -yk*y–7 so that l0myr 7u*)k-oxl:6 l 2jgyzfv the 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 maxitef;z9kh 38g2 v. i4jyjqumq n4z.xx +mum 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 f v2f4eik49j.xt+nhz z .ju xmgq83q y;ar from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separatedm/g3enttr0 z 9 by 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the slits. rg emtn 903zt/    mm

  Light of wavelength 480s uw24(czerr 1h ,6jbp nm in 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 8plefse/vs58 a 6jq4m of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. Whlaefm p/6 s4 8sqv8ej5at is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed ody 2l1;sk6w sscc:g 3wf red light (700 nm) exceed that of violet light (400 nm) :;wdss3y6 kw1scgc 2l in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece op3c3vxn mz jhcjxw/d 6 *3z0y.f 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,hp+lq 3b+aav3a3w3 ;j ty6a9 vr+kgvi $\lambda_1\;=\;450\;nm$ 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 qc8u5(ofnby 4e6bal8 0.0440 mm wide, what is the full angular width of 84q86cl ubb e o(nay5fthe central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on axpx p:.t e u)8pjj7g7v+:b ecc 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 f ix8j;,) siarywa0f.g5 k5eh talls 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 i.bn:8. fvgfp 5p ouc7.mb6kof lluminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction p pf:fb.k8.g5 nmo6.uo f bvcp7attern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength;ori bnl9t weoge)- 09 653 nm falls on a slit. If the angle between the first bright fringes on either side of thi re-l)ew;og tbn09o 9e central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diff2. 9v*a tedazo 1dlo,uraction peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated9.2za,a* oo1vd eltud by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dari1,p 0wvn9ted k bands o0 v9ptn,we i1dn 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 oy58u6,4 +f3biah1tm u v thddzn a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m awayh4mvz3+ u8uf ht,6bt yda1i5d . How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffractiskc4, 0/fpnbnon maximum is 4.0 cm wide on a screen 1.50nkp 4f0,/b ncs m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt rb4ilplyjw6h /a4+77l/ qb i *zc(aygh $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produg c0ek,kv91ut)//bxhr 6dbze z m)y ;ice a second-order maximum when falling on a gratin z1x,ycbk/h6 0k e bzg/vrui9 m)d)t;eg whose 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 doi.o xmsts7 7e8es a grating have if the third-order occurs at an 18tims7 8sxe7.o .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 ocdr ajv45: c1 xwz x+3 xwp)u8dwy+4jsf 589-nm light falling on a diffraction grating is observes+1 v wa5)yj8cwzdc r4: 4x3x+uwxpjd 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+p im8is-l:plf; f.hr $ 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 onth v 3my5(9i3hrxo;uh 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 6000 l.t +cj3*vo eew42;r ,9q nztvo6jvcxe ines per cm is illuminated with*w z.6o qrvvtxj3ecotv+j;42 c ne9e, 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of tagunt2nu (:xf2akc2 rs2( /p/jx e5xp he central mre2:n x/ j2ac(supf( / 5akux2n2gxtpaximum 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 wavelengths from 410 nm to 750 nm falls on a grating wiw dqkc f1i9tu;w )8vi1el5w. hthiul8.;w w1qiw95ed)vh ckt f1 $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monoc 670,aulgm xqqhromatic 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 k+a(dqr; i7oxd) hiy-nd qb6*$9500-line/cm$ 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 strongln/ei gsy u2)3v vbt3,u+8cxiby reflected at the center of the outer surface when illuminated normvyigx+n s,u)t83b/ 3veuci2b ally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass qu ajojzn11k;5n/ fb4 iry5m 2plates are each 26.5 cnf; m2 1rqun55 /jbz1ja iyk4om long?    cm

  What is the smallest thickness of a soap fije/my s+e- 0xxlm $(n\;=\;1.42)$ 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 yellofwqd /kon x21u2stdb4 a 6y*x5w ($\lambda\;=\;570\;mm$ 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 Newx .ho,,pcm7zbton’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 glass surface (Fig..,p7mzh, bx oc 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pvd0-3me zok:k ieces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (wit 3k0dk oze-:mvh one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be between two flat gl:jvty e.-x7w33d7mg e bt8on rass surfaces if the glass is to appear bright when 450-nm light intr o:.w8 vt3 eybx3dg77me j-s incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspzgu hk t(e2-m3ected of being 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 9c msssuri(ny ff2-* 0kgxr19$(n=1.36)$ 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 9-;5ojcy-.siyypx/( h hr rvc(Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decc-vy.i h(xcp j5/9-;s orrhyyreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an inttq:/p-e +5afn ,jjzr rlp. ms)e.1 mekerferometer if 644 bright fringes are cou te/jqmk ezrpel,a) 51-m+f:r.jnp.snted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the +6m7aw+ iy0pv d:nkcc movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil,ckp+0y+w ac7 i6dv: nm 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 mire6 zs25uj:nya ror $M_1$ 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 glass ey1jj6,raq )pcontainer containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 darkj ja,ypr1)qe 6 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 orient1 +y/b13fc deq d4e(z yj.zyefed 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 lr06 c+hb6 j bvtuw)y.air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond sqjur it8+wv81 ubmerged in water if the light is hitting the diamond +q u 8witj8r1v$(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximunuvr:w6 s,,liu mxn;: m. At what angle should one of them be placed so that th, nlm,in;rx6uu ::ws ve intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Pola.:dfbgx q1e* eroids be placed so as to reduce the intensity ox :ee*qf1.b dgf the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at -5q cg f,kah ,fo*j 7-b0ihius40$^{\circ}\,$ 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 orientdi qh)c-poa ega;h;4 ;ed at 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off the surface oyr j05mcbl( q+qov+3of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface ( cv3+olob mqq5+0yrj.
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 sheets, each of ww7whzyb: ml sv89 +u:those axis makes a 45sm9u+wwbv l:t8:h7 yz$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength i-qpx(+ 5qrku$ 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 mo ynx x5zt;9y2nqy3e4m cse-r(untains or airplanes can interfere with the direct signal from t c- ;n5 zsq93yy mtxne(4e2xyrhe 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;m tbr857sr4xj,)xwc)4n3z r y hnfiz diffraction grating with 4fjy cn3x w54;z xrs)r,7mhi)t nb8rz$ 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 pmydt6s3ta a6l.0 (gb590 nm passes through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown waadm t0 .ygas(pt663l bvelength produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from twttw u r3zn+nqf06f0/ qo identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as3n wz /n+fqqr 6t0fut0 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 doorway0pm ot2o15tpz00vgq yvl0jruj; mknn9-kn;2 0.88 m wide, and blows a whistu nky0nvotj-qm5k0z901 og0n;2 l p;2mtrjpvle 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 on ac j-u8z z6f,ae 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 opa2o /o9bgb)c:yoel 5f parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an angle /lcp)b:5b ooe2y9ogaof 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if ther9 g1k)ot9 qkvvydd5/9i pkg9kyqj5 p1e is to be no second-order spectrum for any visib99j19dvkyd/)kkp1y5 p qivgok 95qgt le wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produc j7 ze;,ihln6ct ,ws6sed by a diffraction grating always overlap. What wavelengths overlap exac6eisz jh;,,l7ntw s c6tly?

  When yellow sodium light )cj-s+f* a ki:xo1j vo1wsn,ml j/lg1, $\lambda\;=\;$ 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 gratingq8hzlj45pw9 z with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of two wavelengths, 48pqh w59zjlz $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clear material if a minimum4b5zs 4m 1a6fgcn-sx f of 150 nm thickness of it, when laid on glass, is needed to reduce refn4m g6zf xb-51asfcs 4lection 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 71sv2jojnf 1 i, /tzzdincident normally on a thin sheet of plastic film in air. The reflec/fo7 ,s1jndiz jzv2t1ted 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 neeg;8c mtfd,.2td,l:nfm 4dxt4fk q jx)ded 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-zero2qpsls3z8go3j :yzedq 4412f6y xhy h) thickness for the air layer between two flat glass surfaces if the glass is to appear dark why8xq4 op1jhy:2y34ds z fglshe 632zq en 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light tran9y4yxxa91 mclv uui/of53w v 3smitted through a thin film layered on a flat piece of glass. Draw a diagra u5yiouc9yl4 9vmf/ 3x w13avxm, 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 Sun when light refvu2xd:s(ym 4imf8tc /lecting off a smooth lake is polarized most s4m/t u2cvs8fd y:m i(xtrongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be plac m(*+m upoc;aq8gs9bl w7gy-med so as to reduce the intensity of the incident unpolarized light by an additional factor (ayum7b-m 8a(c gwqs*+l 9gpm; ofter 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 transmissiontfuy(dpvp1r/.f(5g t axes are at right angles. A third polarizer is placed between the first twod(r fv p ttugy(fp15./ 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 succkrw5a-bsw-nch ++ t0a ession 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 sl7g+xae8 b9nfd n:syu .it 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 waveleng9agbf: 7y8dns.x u +enth 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/i5 h4fkny uf( 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 x.j-h s4 ovy zxn.a0)n$(n=1.34)$ 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 or 8v/ klcxw, fo/yq (0sp,r9o;ikedkbnl9.o,ther. They are locates ev( ;/nk ,kkq ,oolxb0/,cr.l8 drpwi99oyfd 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,yx3 2au gj28gy 420 nm and 650 nm, enters a 2y23x 8jugayg silicate 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 len*.93 bhhwghuxv4 .vohav -s 1-vfy uj0s has one flat 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