Does Huygens’ principle apply to soux :w pq-tty.:snd waves? To water waves? Explain.

What is the evidence that light is enerwdif7b4qf u f0 .v:wxrea/2ac g7x39agy?

Why is light sometimes described as rbkh9 ix0t x1s5,2 7pciufzo m,ays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; yet bothd0uz 6;f yk2mv sound and light are waves. Explain the differe0zuk vdm6y f;2nce.

If Young’s double-slit experiment were submerged in water, how would thycgn 8bg *.r3ue fringe pa*3 gnug.bcry8ttern be changed?

Monochromatic red light is incident on a double slit,ztv x 3c z8;1wp)8(bgzkebl4s and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would c8g)z 8pz; v(lbzb4swk1 cetx3 hange if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if thtj)i0pe m/8 2+n ifkeieir path lengths differ by how mucht8n ei2 jfpiie0k/)+m?

Why was the observation of the double jxf6fji3g x59q3alx 2-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffractix3g jf 6a3i2xxjq9 5lfon?

Compare a double-slit experiment9 j91z28 fr/gifvjb4f7npenls6y j w0 for sound waves to that for light waves. Discuss the similarities/n8 4g 1ffsjf6 ybr2wvji jz0 l99pen7 and differences.

Why doesn’t the light from the two headlights of a2gzl1s ew ry6,() xyxp distant car produce an interference pat,g26e ls)xzwr py1yx (tern?

Suppose white light fallrm s-ff* 1d on.;+2vlihu3w kjs 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). Describe the pattern on thuknjd+f- fm2.1sih3v o;r w*l e screen.

When white light passes through a flat piece of window glass, it is not brokeny4e . s /lv8/hacxvg,j down into colors as it is byh 4 ,/.elj v/ycaxv8sg a prism. Explain.

For both converging and diverging lenses,xwa ho*0 1*ogl discuss how the focal length for red lig w*1oh xlo0a*ght differs from that for violet light.

A ray of light is refracted through thr4w/lc+fn1ov ny , abvlq+)r8 vee different materials (Fig. 24–55). Rank the materials accordingr c+al81vv ow4nq y)b/fn, v+l to their index of refraction, least to greatest.

Hold one hand close to your eye and fosk 0uaojo5vz0 7. oq0+hx/;v ep nt*iubz:v1gcus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.7iqu:+asn0k;0 uotxv*zj.o /e v bvohzpg 051) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the whole iyr9 aq5smn/57ng8ym apparatus is immersed in (a) water, (b) a vacuum, instead of in air y5q mgs /5r8i7n9yanm.

For diffraction by a single slit, what is the effectl7ps)ke6qmm2zfd-t)r v -9mfr,n i0 u of increasing (a) the slit width, and (b) the7p)ztn)m6e-si, mr v0f9f lr2 mu-dqk wavelength?

What is the difference in the interference patterns formed (a) nw6le,mkg iz;b w8-2oby two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the advantagi09a o- w-yf/qrc bs2zs-(blge of (a) many slits, (b) closely spaced -2c - si0q/ w9-oafzblsyrg(bslits?

White light strikes (a) a diffraction grating, and (b)tav k ps5k5 o7:4mc+ut a prism. A rainbow appears o:7a4mtv p5ks5 ct+uo kn a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nm, incir *9rx+p 0ac(,c wiheadent normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depcir,p0* acxw+r h (ae9end on the slit spacing?

Why are interference fringes noticd.+ 6 esx-nfr0/9bu+7ei-kdveyc ex geable only for a thin film like a soap bubble and not for a thrs0ikb/-ye veg +-+xde. 9 undx 7efc6ick piece of glass, say?

When a compact disk (4 donl3xdaqx3 wbn 7n 2d9c3u(CD) is held at an angle in white light, the reflected light is an2cba9u43own7xql 3 dn3d d x( full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer togethehspl5m 6ic +l1r farther from the center?

Some coated lenses appear greenish yellow when seen by reflected k6j-a8-zg i c:y8a ( c6*spizvaiv p0clight. What wavelengt(* a0i ycs - cpkacv8j6:ia6vzz8pg-ihs do you suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at it)sm rvu 21v6zjt.o*1dvlgb, ps edges, where its thickness is much less than the wavelenbtv , *j211m up)s6gv odlzvr.gths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us abe8vs:jo smn j;- h*os(out the nature of light?

Explain the advantage of polarized sunglasses over normal tinted sungla2 )ylz/.d7ma n qnnsvs6that+.8n ;hv 3gsn/dsses.

How can you tell if a pair of sunglasses is po+0w:/79 ux- n ugal orpfl luu5jv7k;clarizing or not?

Two polarized sheets rotated at an angle17 4j2 6b*ustiz-kwctals b6m 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 scxo5b )dtmz+ 4h):gop ky if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times denser/+s3 m naod8me than it is, would sunlight still be white, or w 38a n/m+smoedould it be some other color?

  Monochromatic light falling on two slin0qjo2ov 9f;0(zfuw ots 0.016 mm apart produces the fifth-order frivz9(o ;0ofj wqun2of0nge 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 angli5fgp 34u ,wkhroz 1(yqd)/xee 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 slbd2kh.x 3h)drits 0.048 mm apart. Successive fringes on a screen 5.0d.hx d) 3bkr2h0 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a w wn+alyu-osf4kr+ i(; avelength 656 nm, falls on two very narrow slits 0.060 mm apart. kruif+; s-ynl+w (oa 4How 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 two slits and produces an )sc4ofv3z yze8nf1* zinterference pattern in which the fourth-order fringe is 38 mm )zz y4n fsozf81vc3*efrom 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 passes through tqqk84 wigs s4 6;fhrm:wo slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on ;h ris:q6 8gsfmq4wk 4a screen 1.0 m away?    mm

  In a double-slit experiment,rh6awldt, ze:m(v/ r4 v w3xmh.hu3 e, it is found that blue light of wavelength 460 nm gives a second-order maximum at a certain locatrr(, wela.d uh x3/em:4z3tmw h ,v6vhion on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two ; bessz05jv22y. 73su dzlrsmopenings 5.0 cm apart in a board. At a point 2.0 s. ;7uvjmzr2esssb2 3l z0d5y 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 lowd qz(wl; d)-x1g50 isx4bcszxer slit in Fig. 24–7 so that the two waves enter the slitsx5-)zsl0w4qdixzg x c1db (;s 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 thirdu((5nyx ke (sf3zn4t z-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Lign(e kutf4zzy (x5n(s3ht of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminatednoyht7:sq8/na o 0+dz by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from qoa0 o/t7+y: nnz d8shthe slits.    mm

  Light of wavelength 480 nm in air falls on two slv j/(o9ups6 lyits $6.00 \times10^{-2 }\;mm$ 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) co u-,sldr9 iy-a-z( pimwh-da 3vers 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 3-dph9au- ,izd-mw lrsy (-aiof the plastic?    nm

  By what percent, approximately, does the speed of r1u ao ce +51nlv,m7obg z 3-yq78igxieed light (700 nm) exceed that of violet light (400 nm) in g5u73iml+ 1g y,zc7ibqna8-xoevo1e silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at .m5-/g c.; xijw bzopr 3ibm 8d;p2lfoa 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 wa95kgsoc(roj1k wk( -a velengths, $\lambda_1\;=\;450\;nm$ 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 sli+vy alb jnyx/f k01:0g c,(ihlt 0.0440 mm wide, what is the full angular width ofy/ xh( ivn0a+by j kgl0:,f1lc the central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls1u kf3,6s5nv fgfojz m7t9q dio0z+c+ on 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 sli xw;f1nm/x iov3 ong37t 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 illuo sr ku4+q5 0medsec 0jfwd:y/5rcs1/minated by 450-nm light. What is the width of the central maximumw s m5eoq54s+ 0yurfcdj/ ce:/0sk1d r (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a .0yhplim d 89 -8eklnxslit. If the angle between the first bright fringes o-p i8 0lxkyd.hm98ne ln either side of 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 0.0348-m b)zp1ab -rry 1u2k:w4rd4k-bmq - zvum-wide slit illuminated by 589-nm bzz-kv-1r-mdurp w 1bra uqk )y4 2:b4light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first dark i0oqboe26.m+o 8g gw tbands on either side of ceb+i. q68o2go weg0motnter are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on am (z5q5w- fvixo58cll single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that o( czi8l lm5 vqfx5-w5is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that thelg ,zkeb:)8 l-0lzpsl diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maklez)8 g0:-l ,zplblsximum for light of wavelength 420 nm?    cm

For a given wavelength7xpy 7b6ptq,b :tv bj6 $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produmuz0 umcs;6z 0ce a second-order maximum when falling on a grating w6mucz; u0m0szhose 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 cento0,vx+2ridl himeter does a grating have if the third-order occurs at an 18.0hrvdl+,2xio 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-l+*ep2i l5-v( rhe6xox d,rgs p24 rm:(uzovxnm light falling on a diffraction grating is observed at ,dgixoovu:h s lp 4r+em65v2rx*(r plx -(2ez 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 hae3n gzfm cf7(s:2olv(s $ 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 normallyheoql *4xrl,zi* v:t6x 5 8zlp on a $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order thd ehww( ,;m grp+y3h:u+:v ; wajf1esfat can be seen if a grating with 6000 lines per cm is illumin(+ pd:h, ujf;gwr3+hfwee1ws;v:ya m ated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral ordersaf s:n 7qpuy+7 can be seen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for thef:7pa y+qu n7s grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wave) 46setgcqq0 sgt2s( ulengths from 410 nm to 750 nm falls on a grating withs s(6gc qg eqt)20uts4 $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochrm;s-5fz dq v;romatic 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 meab ak*b)yrd 3:dsured 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 o 6f-yj) cd*ffhy7ngd 1h9j1 n120 nm thick, what wavelength is most strongly reflected at the center of the outer 61fj*-)y dcnohj19yfn 7fhgd surface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dauk m+eu1 4lkmq;, gxuo6d1d +xrk fringes in Example 24–8 if the glass plates are each +dmm 1k6q u+d4uulk1 x,gex; o26.5 cm long?    cm

  What is the smallest thickness of a soapgb rj:*hx4nb) ) z9ypo 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 xk0r;l2t/;iqhzb.. ng ip bt( ($\lambda\;=\;570\;mm$ 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 th0d :2fk);iry -y atowa5hn0sxe dark spot 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 the center thanawta-hx;f5ry 0)0d y2n so:k i the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically fl hnc p-9kckpz;r:tc-ad oy1;9at glass, as in Fig. 24–33. When light of wavelengpcpa y ct:;9-d1nor; kc9-z hkth 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 two flatq* kjhmqei8o+n7/( dz glass surfaces if the glass is tm i+h( ned8o*jz/7kqqo appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a o6 uuo1m/c)v6zwi xl0stolen 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 alcoh f65.ysxp. pnn (5vnpxol $(n=1.36)$ lies on a flat glass plate $(n=1.51)$. When monochromatic light, whose wavelength can be changed, is incident normally, the reflected light is a minimum for $\lambda\;=\;512\;nm$ and a maximum for $\lambda\;=\;640\;nm$ What is the minimum thickness of the film?    nm

  When a Newton’s ring apparatus (Fig. 24–31) is immep0 8,lj mj(xp0/;).:+fswbh wnrskbyjxj9 s vrsed in a liquid, the diameter of the eighth dark ring decreases j j8p0jrxjnpxyb k v)(sl/:.9w+0m fwshs ;b,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 intes8f3b9+ok34 x osp8bvxli 1ixrferometer if 644 bright fringes are counted when the movable mirror b3 bsx ik+loxo8v 43xsp1 9if8moves 0.225 mm?    nm

  A micrometer is connected to the movablene xt smu* di6;)v-zlt;g8s:o mirror 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 used i8t; l dms)nv:6ue-t gx;*zsios 589 nm.    $\mu m$

  How far must the mirro3-vj6craq;8osi 1eh 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 (Fig. 24–59) passes through a v1 ) x 8ovbqk0,req9ehsmall glass container containing a cavo8q)q , 0xk91 vrbveheity 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 interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at 6lifc68kqr2 wqco1) q 75$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle fo sh+qrrv:8/ zhrhu:3rr an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if a;i(upsg8.3jdm a, lrthe light is hitting the dil,; a3ui8msp r( gdaj.amond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them ijw :ab/p3 bs eh2b7o0fmvm93ps a maximum. At what angle should one of them be plac sjhm2evb:pf3 pmbwo 739ab0/ed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to red, jc-,0ags g hw;0jgjbuce the intens gs,bw,cjja0 ;0-gg hjity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orik3 v;o *t5uar3irao 2iu 4-tegm)ek-oented 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 cvf r.cd5 j.l(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 t*7z)0 rotj70q uxs kggz9ikk1 he surface of water for light coming from beneath the surface? Compare to the angle for total ing ) u70 kg7xz0*kojqs9irk z1tternal 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 through five successive Polaroid sheetsqau,lhuj7 ;7 r, each of whose ajhqal 77ru,; uxis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength r la.+*xbwv7hdge9(v $ 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 intep;m, -f.; uwnt e*yivwrfere with the direct signal-w; ,neui.v fw tmy*p; 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 through a diff xyzgl/j id;j sw2y2x(el (;5hraction grating with yy 2sx /;5ejj; hli 2(gz(dxwl$ 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 twomc(;rvu9l m*r narrow 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 9m*r c; mlvu(rthe 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts f3r4gvw yca6, )3 9rh;lxkp kuh*em9ejrom two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum siv) 9w3ukrc; h4*mher 9 ,ax jgk63epylgnal 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 an outside doorway 0.88 m wide,e2xs/b*y x v5p and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground ou x52xyps *bev/tside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of width D at a vqytt9s.8(c9oc 1n no30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lines across them. eh z o0)l+amq bibf-32When normally incident 460-nm light is reflected from the wing, the wing ab mzoi eq+lh3)b-2f0appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there cq u gr nd8pe4yti988mwk+s (2cg5p1ris to be no second-order snryq5 tdi 4 +8kuwp2grmc(g89 8cs1eppectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by a difp0d /jxks brd0i*-r -ufraction grating always overlap. What pr0rsk-d bx* j u0-i/dwavelengths overlap exactly?

  When yellow sodium light, pr1 y5 +dwantfwcp73p;t p /w+$\lambda\;=\;$ 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 and the pattern is vc3m .j;punva5 04rlp kiewed on a screen 2.5 m from the grating. The incidpjpm5n0c4l. a uk3 v;rent 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 a minimum of 150 n,yzfi 3p8f)7u t qg8mdm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is ingdu7 88ymf, tqfi)3 zpcident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength i :n nc/ml+repn26dky;s incident normally on a thin sheet of plast/p cdle 6;:nymnr+n2 kic film in air. 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 neekd6 4* u hcb(fp( u3/xstef8fa*zeub-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-zer nypkd+*kis g0qoynk1oz t/g5l880p:o) thickness for the air layer between two flat glass surfaces if the gi8y1pdly0n8pk/ qoo :5s*tzk n +gk0glass is to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the li7et +(3ntupw bght transmitted through a thin film layered on a flat piece of glass. Draw a diagram, sitw t(3np+eb u7milar 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 f:9w2wq ugq3rtmufz +;pmvqxw246/l is the Sun when light reflecting off a smooth lake is polarized most st3xzmw u mlwru:q+ fq/tv gfw ;q6p2942rongly?    $^{\circ}\,$

  At what angle should the axes pj6i9kx./j rfof two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional fact/xj6r. ifkj p9or (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axes aw0ha(ckx58w.4zaw pu re at right angles.(8wwhx0 a5 cku .w4paz A third polarizer is placed 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 with theio ..fpv 2scqenif 04-br 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 slit of width 1.0 cm and is pointed at the Moonxl rwki rs41.8d9ip8 q, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red lightr9q.ixw ik 8 pd148srl of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are each placed at a 1g +qk vmz49ivkui o,1;0$^{\circ}\,$ 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 wc0m; 6 jsy)ecj9 a ;ub(q7uvf$(n=1.34)$ 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 waa 67j1ye u1gpuxd bg2,ves in phase with each other. They are located apd6ega 7xu1uby 2,jg1t 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 andhdoqkc 5vk+ d28k4pkn*r*uf6 650 nm, enters a silicate flint glass equuk2k*h5 pdkd *8 v +6qfr4ocknilateral 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 withod l4 m g8c0dy1l01wfc $R\;=\;18.4\,cm$ 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