Does Huygens’ principle apply to soundcu;ku 5i)ge.vqhynn+7; fqx: waves? To water waves? Explain.

What is the evidence that light is e:t dk w7nv 7 ,a0ulxifzq-q /,ps/6vij1 ljr:energy?

Why is light sometimes described as rays and sometimes asdovxkv4t/q0g4-bl)ajfy e 0*fzg8i- e juj1* waves?

We can hear sounds aqm3.xdw o8 nb95f9-1w iw(+pem d tvoj(u i:mbround corners, but we cannot see around corners; yet both sound and light are uj dwmw3f5b-di o+qpv b9im(t:m 9n.8x1oew(waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how would the b:mqqh-. clia zo6f; s- i+89trjp1fb fringe patterncq-- omibtqr6zil+fj:f 1 .;bp8sa 9h be changed?

Monochromatic red light -ztg j2sqwpe*v dh-x(0tb8y 2is incident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light so(t2-eb-yj2* vzgh0t x8w qd psurce is replaced by a blue light source.

Two rays of light from the same/whrv64t(fd g source destructively interfere if their path lengths differ by howhdg(6 4fvt/r w much?

Why was the observation of the double-slit interference patter f+itlo,/*qlk n more convincing evidence for thlf*toli+k q/,e wave theory of light than the observation of diffraction?

Compare a double-slit experiment for soundps8 hy7p(n1fvpvjg/l-a76gq waves to that for light waves. Discuss the similq 61js/(g-g7v a vfp7yp8h pnlarities and differences.

Why doesn’t the light from the two headlights of a distanw ;3w:uvm0xo zt car produce an interfv0m:u 3xo;zw werence pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit)jy; 3k v 1xwo73judvjlx7hs9 is covered by a red filter (700 nm) and the other by a blue filtej7s7u)v;xv3 9oh k w1xdl3j jyr (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of w0, p kmz,atb/0awdm.ig w3)a rindow glass, it is not broken down into colors .3a ma/ pz,b),idg0w rta m0wkas it is by a prism. Explain.

For both converging and diverging lenses, discuss how c fsjrn b i)p*nkn5u3o7t9+, pq15 a xyub8/rhthe focal length for red light differs from that for viol,r )y p79a5sb+k/unc* 8 rpn3u nhtq 1bi5fjxoet light.

A ray of light is refracted through three different materials (Fig0/5b k-nsnzk r. 24–55). Rank the materials according to their index of refractk0n sz- 5krn/bion, least to greatest.

Hold one hand close to your eye and focus on a distant light source through a x64rvn*n(w y l.dz; j* ,jvo y6bncw:anarrow slit between two fingers. (Adjust your fingers to obtain theya**:xvln(6ny4 bwwvjd ozr .jc, 6n; best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the wholf 6 .ocsi -fljpa;h4,ee apparatus is immersed in (a) water, (b) a vacuum, instead of .pohc4faeij6,- l; sf in air.

For diffraction by a single slit, what is the effect of increasing (a) the slitvvm r :e4 qojznn,4w-9*4uts i width, and (b) -rs4uv*:w9e,nt4qm jv z4oni the wavelength?

What is the difference in g ; ;ozxy8gap0the interference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the adva6:dhnh s)tg ckna+p 3uxy/)v:ntage of (a) many slits, (b) closely spaced sdghy +:)ksu36ph/atncx :vn)lits?

White light strikes (a) a diffrk v6ylxamt6 9(action grating, and (b) a prism. A rainbow appears on a wall just below the direction of thv( 6tya lm9x6ke 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 ly*me5,v3h7)xl -h6z heqg tpnm and 700 nm, incident normally on a diffraction grating, for what orders (if any) woyleh v)lzth-h6 75 p 3qx,e*mguld 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 s d.a t8xk,3 jn.owp.czoap bubble and not for a thick piece of g .axwt.8n.d jop,zk c3lass, say?

When a compact disk (CD) is held at an angle in 8hxu0.j(q ce: lum0pwwhite light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect tm0qceuh 0p:xj (8.ulwo see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) cb+/0yul xtlk, hb: vs8loser together farther from the center?

Some coated lenses appear greenish yellow when sec 0ggb/uc0 sl,2.dblfen by reflected light. What wavelengths do you supposel/0d u2,bbfgg.cl c0 s the coating is designed to transmit completely?

A drop of oil on a pond appears bright vbq05ii1ekflk fj:4)q) h-quat its edges, where its thickness is much less than the wavelengths of v)ifulk q:v)f q k10-eqb45jih isible light. What can you say about the index of refraction of the oil?

What does polarization tell us about thet.c1wfj msu.v(7g nn;j9 lou) nature of light?

Explain the advantage of polarize4o, jowkxma()a 5,zf kqomr09d sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polariz34 2s1)i0p :stx:eq zqeq dq2rnoblh(ing or not?

Two polarized sheets rotated at an angle of q/h s6bh(j. awu2zl-o90$^{\circ}\,$ 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 tt0r1l o,8 gf:p1wdkh-erar4che sky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser thahw45x:b2qto* aq5xpq qft r3j)5xes 9n it is, would sunlight still be white, or would it be some other color3qsa2ft q op)rxxqw b: 559th54*jexq?

  Monochromatic light falling on two slits 0.016 mm apart produces then e bkft8)/0gbyeq7 , 8eqt4qnzl1gv3 fifth-order fringe a,n t0bg1e /yqe tg7)evzknb3 8fqql 84t an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm lii4r ajuq;5v 6-b/glk oght 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 tb6jf /ffvm//aep:,be7mya rjj / fz*s (uaw 6:wo very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of thes afwj/be6/ * fa r7ub yz:mjfjev/m:(/fa,p6 pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a H 7j8 :mklzev;diq 0+kme-Ne laser, with a wavelength 656 nm, falls on two ve0e7ji;dm8vkz mlk:q + ry 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?    cm

  Light of wavelength 680 nm falls on t dy 3t326zruh vqlr1-rf6q e*iwo slits and produces an interference pattern in which the fourth-order fringe is 38q3z 6d32vq u*rtfr eih1y6rl - mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light pa- gyt dmzlcd:-xh5 g4lo x88+wsses through two slits 0.58 mm apart, how far apart are the x lc+dz lmt:dxw85 8oyh4g--gsecond-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit expercn/5 5 wu)pgfkiment, it is found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible lighpwf5)g cu kn/5t would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apartvv.g (z3i*)2c dpg/pf af9hj w pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what a ig)vw9ajfzp v3dh2p /(g* cf.ngle 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 t2vmo9 w-m.u5a wt nhx+he lower slit in Fig. 24–7 so t.5o wa-mw+xvuhm9 t2 nhat 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 maximum foruk/ h(sp(7 1v)nwkgw t light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from th1(wthk ) (ukgs/wvpn 7e 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 1.0bq y-ywm*-/ eqce 93kx mm are illuminated by 544 nm light. Find the distance be-mxbwq e k9*-y3q cy/etween adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air qg7 w2a3csx+dvr*.f j falls on two slits $6.00 \times10^{-2 }\;mm$ apart. The slits are immersed in water, as is a viewing screen 40.0 cm away. How far apart are the fringes on the screen?    mm

  A very thin sheet of plastic (n=1.60) covers one slit of a double-slit apparacc 1r8d wu1z3:j ifeln (r59gstus illuminated by 640-nm light. The center point on the screen, instead of being a(g 18wns1ref3 j duzlr: c9ci5 maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed 49+u ,w*gu cjpnnjia3that of violet light (400 nm) in silicate flint glass? (See Fig. 24–14.) jij+uncp awg,43 n*u 9   %

  A light beam strikes a piece of gls;h,.qct- (ky7yd fkp ass 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 hogr6wa y7*u2uka rb f.i*m :6containing 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 wide, what is the full angular 7 oht )kxde0cgo)md3- width of the central0kdmot c 7gx)3)e h-od diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a(i2q)s0yn:etyu :s.rdvm g1w 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 fq17q .,eufq2xce 9fnoalls 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 ihyjnk: q9f ./: creh,mlluminated by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on a scr /j qhhnmfyk.9::ce r,een 5.0 m away?    cm

  Monochromatic light of waveley kh+ahw (e qo g;7c7hsyh2e38.7owka ngth 653 nm falls on a slit. If the angle between the first bright fringes on either side oky(whcw7 a;eeooh8ha +g .sk 2 y37hq7f the 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.;hfa7dwr,;mh g:o t :uqt2dy *0348-mm-wide slit il7g*,wqt2tf hd o; rhay; mu::dluminated by 589-nm light?    cm

  When blue light of wavelength 440 nm fall2j(ss pj,gk ag 1alm;+s on a single slit, the first dark bands on either sis 1mgjjga(2as kp,;l+ de 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 single slit, it c6op.0-nc ulbhtg s+ra h08 8kcreates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is trct0cbs kh88paln6- +o 0 h.guhe slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum is 4.0 9;83 yg 3osjyurwz (u,hwu h:qcm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light oy9z3w(usg ,83:rh w uhquyoj ;f wavelength 420 nm?    cm

For a given wavelengxctjavyl c/ j ,qu()0w14fk .kth $\lambda$, 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: u,wqpic.0j)yxik. hf 43 tnk maximum when falling on a fy :wx .),u0kjnck 34i pt.qhigrating 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 does a grating have if the third-order: xosduvu * a;x*p wztn+2ax8f6j4:wh occurs at an ot;d hfj wzxwua+*:4s6vxua*xp :2n818.0$^{\circ}\,$ 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 fpks w6n kgj-g*8jpw :ii6fu0)a:x o;aalling on a diffraction grating is observed at a*wajs a8kgu;fp:6x -kwi6o)gj0n :i p 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating h82)ed 4kux4elm2s jn (p bvv:vas $ 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 hq;c+ bajkf ri(u0f*6w tek63on 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 kx6iubj5 a9u 1 e y5jje2)pcp -v:b8xy6000 lines per cm -jjkbvb9)exi x ue6 85jcu5 2aypy:1pis illuminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of the hey*b5 nq53 ddcentral maximum when white light is sent through a diffraction grating. What is the maximum number of lie5dyd*b 3n5hq nes per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths frc 32jg fd6.d-lhebc3zom 410 nm to 750 nm falls on a grating with dc-6 fz3led 2cjb .gh3$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser whiov641 )jqhw rh/q s+prch produces monochromatic 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 arv iqw05zc7 mv9e 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 wavelengtpq6c-fmg;r(ver9 a6 exo: :gyh is most strongly reflected at the center of the outer surface when illrmor q6fg c:ae6gy-xv (:;e9puminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in * /d97f/zf kdyy8zsiia .yj2qExample 24–8 if the glass plates are each 26. f8z.q* //djyzi79sf2 dyak iy5 cm long?    cm

  What is the smallest thickness of a soa j 3x1:i.vi:yvj 2uiynp 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 greenisy7 ,8jaru;kn8ac-cx sh 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 Newton’s rings (not countj:rd) jf g,/wping the dark spot at the center) are observed when 550-nm light falls nor)jp/: wgfjd ,rmally 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 pieces of optically flat )c+mg*mpu +woxzx e0-glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observpew +cm ox0)m +ug-xz*ed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) sdn6p;llhiyhqxt -m v3-r.6s/hould the air layer be between two flat glass surfaces if the glass is to appear bright when 450-nm lightql xndml6tih /rpys;3. -v6-h is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material;3q / 9sg6oqlrufwb0yz 8o1yp, suspected 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 alcoholyt*tw),rk z21h: .a bi ghczt7 $(n=1.36)$ 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 lp2 bkuzlc6m8 15 w ydrg71tq;apparatus (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of tzc7q2l;ldw15 p1 8m ubktr6gyhe liquid?   

  What is the wavelength of the 1 ha8 yowtoxj5f/:a)l light entering an interferometer if 644 bright fringes are counted wh1t:j/ wao5 ol yhfx8a)en the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirid 9ahu;( 1g ro,henq:ror of an 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, is 272. What is the thickness of the foil? The wavelength of light oheg1q9u (iad :n;r,hused is 589 nm.    $\mu m$

  How far must the mirrwhputm6 9u)m1 or $M_1$ 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 (Fi um p-g4wej(*75 bhsveg. 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 line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interu w(5gsmpe hb4v*-ej7ferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 654(2b nk.a4sa p2v;:y pbq qtkl$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anglf9l5( jam9qcii-,vnqe for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle fw o qvx*l-s;k-or a diamond submerged in water if the light is hitting th lxsv;-okw-*q e diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that t th0k 9wag9zy3he light passing through them is a maximum. At what g0wz9h3tk y 9aangle should one of them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the ikvmez. o1 9wc+ntensity of the incident unpolarized lwz.+ ekvm c9o1ight to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orc6zf0jzx( ki8 iented 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 atfa/(s (uf81v, qx une t ifzaa:.mzm4gr335dx 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 anglerjy-i vq93r 6p 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 Brewste36qyp-rj 9r vir’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 sheets, each of whose6 7z n(sc;f:o*tpq o+we ibsy0 axiiso+:(;w co 6sqf0 bze*ny 7tps makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength a;w- eth 5hftoq :h5;t$ 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 z6 hmy6guetpau8*j , x/.4n tzinterfere with the direct signal from the station. p8z*he ntay6ux t,.u/j 4gzm6
(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 diffractioggfqn+ uri 9nj9-vn 2 i t2yl40hr-9zwn grating with lj ihvn4 q i09wu+nrzf-r 2yt ggn99-2$ 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 slaqwz-,8xfp8 jv j2m* mits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fring f*8z-82x vjqmpmwj, ae 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 two if8c zf tp,:+kidentical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig.: if+p 8ftkc,z 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back from e i-6p6 qt furh8vs,27 seerp1an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what avs 1erpf6e8r6i q-pth ,u27es ngle(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 falcz *s+mjr8eqn-4muc+e 7n9qils on 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 parallel/h t rra+w-0-)gaifsc lines across them. When normally incident 460-nm light + af)grch-0st - rwai/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 centimeter59fj ly wd,dlga o(q8m-8q;i i must a grating have if there is to be no second-order spectrum for any visible waym;-i9lqjd ,8wd8fglio a 5q( velength?   $ lines/cm$

Show that the second- and ts1fjl-jzviql :2e 1:ax* af u.hird-order spectra of white light produced by a diffraction grating always overlapfi uj zf.1-x 2:1*laqela:sjv. What wavelengths overlap exactly?

  When yellow sodium ligh(8q(8tj apa9s.akb6q .wzy ott, $\lambda\;=\;$ 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 a5n+s)1we-kfccgj ha:/ xu r6 z diffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. Thxsnf)c1rj-k /cug+5e:ah6 wze 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 ;dym:e*r+g b u-mu;feif 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 normally upon +mguy-;bd;r* femue :it? Do you have a choice for an answer?

  Monochromatic light of variable7k j,wbnnb05d wavelength is incident normally on a thin sheet of plastic film in aibjknbn7 0d5w,r. The reflected light is a minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an anti-r y8gmgs aeo+12 qi ;k,ant+ uvos1pd.8eflective 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 ailz jb c .sny*as8b.h3;r layer between two flat glass surfaces if the glass is to appear dark when 640-nm light is incident normallycjh bs*b n;l8az3.s.y?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitt, 8w- eyktso )hvuu6v2ed 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 conditions requir v uu o6t2,hk)e8y-vwsed 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 reflecting off a 4h up7arwx. 9 zob tdar-gytle2o1653smooth lake az t1t97rh epga2-ou. dx4yl r5w6o3bis polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids gphf8cqh8 05zzyulo z* 03sjy 7ha:6dbe placed so as to reduce the intensity of the incident unpol 6h j85c7y*zh lq3pf8h0d0 uzyzg aos:arized light by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light fallsrqqx -nk1g 1cz3 a4g.d on two polarizer sheets whose transmission axes are at right angles. A third polarizer is placed betwerag4qd .zq-1 3kg1xnc en 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 placeirs+y3ktd 8 iv3s0on* d in succession with their axes vertical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a sl0 sgcz+3s a-m07crqwv 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 wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the 0+3grw s-m0sa cvqc7zbeam when it reaches the Moon.    km

  A series of polarizers are each placed at a 19ge.fo7f(ep0yt: h ef0$^{\circ}\,$ 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 kr)p5 yswmj3 6t 8y-rs$(n=1.34)$ 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 wa4 tj, qr*vc9c:zxb 7 1t9cowhcves in phase with each other. The:j v cc749rox h*wcbt1t,qcz9y are located 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 li1e,duh,5 f ixlght containing two wavelengths, 420 nm and 650 nm, enters a silicath5 i,dx,elf1 ue 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 surface and one wili.kycf -kr .4th $R\;=\;18.4\,cm$ 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