Does Huygens’ principle apply to sound waves? To water waves? Expla ;e*o0zn 0ihppp9c-a xin.

What is the evidence that light p vd3xe9(0n )id imi.kei7l: wis energy?

Why is light sometimes4 sm 5zh 9.wi-lihw2yq described as rays and sometimes as waves?

We can hear sounds around corners)sx,: mq+5es fu ya*gl, but we cannot see around corners; yet both sound and light are waves. Explain the d f:xs,l5a g u)sq*emy+ifference.

If Young’s double-slit experiment were submerged in water, 1zy8bgow7emgz 4m )8 yhow would the fringe pat1 em gow)8 byg8m7zz4ytern be changed?

Monochromatic red ligh:vmblm thp+,16o pet ojz5 n*,t is 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 source is replaced by a bljp p t+m,5et6* v1mno:o lhbz,ue light source.

Two rays of light from the same source destructively interferen q:sl3v6;:mhfsjg c4 ww6v r1 if their path lenm:fs1nq6j4s rl;w whvc g3 :6vgths differ by how much?

Why was the observation of the double-slit interference pa,kvl4 -zszop3 6p7t7szqhh 5s ttern more convincing evidence for 7phks,5z7z szlthps6vq4o- 3the wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to 7voa +y,uq + a:z;jwgwthat for light waves. Discuss the similarities and differenc;ayj:owaz+ wg +vuq7,es.

Why doesn’t the light from the two:x,8l 1ef cmydk 4h1iu headlights of a distant car produce an interference plh8,uyd mcxi: fek1 41attern?

Suppose white light falls on the two slits of Fig. 24–7, but one slitf34 asc 0,m8ce rie)pq)5qd uy is covered by a red filter (700 nm) and the other by a blqepqu),id0 scac3)r4m58eyf ue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glr2 5dcyxgn1n(6-+ i ieloek )cass, it is not broken down into colors as it is by a prism.1xlnycreid)6+c i2 o( 5kn-ge Explain.

For both converging and diverging lenses, discuss how the focal lep rkw g:(gej 34yjcx8 ;/ka3oangth for red light differs from that for v jaxypegra;3j4 :k8g /3wkco( iolet light.

A ray of light is refracted through three different materialuw2iqn(pgw) 2d6 xe7 zs (Fig. 24–55). Rank the materials according to w2uw2ipn7deqxz 6g)(their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant lighty)up 1r 3*syrjeoa21s source through a naros py r e1sj)a12*y3urrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction p1 dp-zyw: e6u wpkjjh,p;,9 rvattern of a single slit if the whole apparatus is immd p1;, wz, 6 :phe-9pkyjjvruwersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increa ,39jxexul o6j 6v4tlosing (a) the slit width, and (b) the wav,49 6otllvjox6e xju 3elength?

What is the difference in the interference patterns txs(f lq*wv 7rpec.rlx3w 6 5,qf)t 1nformed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what is the .7m4 d0u 8rtrgx/bxyoadvantage of (a) many slits, (b) closely spaced slim.rx8xt0o 7ug 4ybr d/ts?

White light strikes (a) a diffracti nzid2 lv:8v7 7fhf1y.j lwb;ton 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 top of the ra2t1hl: fvblzn7w ;ifv.yd7 8jinbow in each case? Explain.

For light consisting of wavelengths between 400 nm and 700 nh- *2udq,z zfd6mw4dim, incident normally on a diffraction grating, for what orders (if any) would there be overlap in t*-ud,qz wm 62dhiz f4dhe observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a.cb9. 1( qpmf2 xv1)mnmy jyztpyoj80 soap bubble and not for a thicy)c.o2 . qx jym1zvptn8f mb09 (jypm1k piece of glass, say?

When a compact disk (CD) is held at an angle in white light, t ogbq;g.k 4:.ngz:vgwn1 ojc 9he reflected light is a full spectrum (Fig. 24–56). Explain. What wov;k:zg 9w4.gn .oj:g bng1ocquld you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig.d *.so8c8fb5:vk ry hg 24–31) closer together farther from the center?

Some coated lenses appear greenish yeig8h;3yb-rat40/h adoab f,g )4 kgfvn++qd sllow when seen by reflected light. What wavelengths do you suppo0y38d do4 r4)fa tqkgi+avg gbh;nh-+/bf,sase the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, whereca mh ;/o1x5n 6g1o lbqwtm+k.:(ekbn its thickness is much lessekkn. t h5x1ol61/+qb(:ac mwn;m bgo than the wavelengths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us aboujdy 4-rtwx 40 dwene))t the nature of light?

Explain the advantage9jc9*pea - vkb of polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizq2jshdxez 0dhp;h9 ,:b9lhw1p(bs f* ing or not?

Two polarized sheets rotated at an angle of 907u6wk jgcdqci i/ b5q+nr2p1+$^{\circ}\,$ 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 sk; rbi,gka jr*h:+ m(eay if the Earth had no atmosphere?

If the Earth’s atmosphere were 50 times densek/ unu1ouq g:7r than it is, would sunlight still be7/quugu1 :onk white, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apartb99:qtlv *gdxfw6do 9 produces the fifth-order fr9vgt96lx :*9f ddowq binge 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 anpbm*;,ig)knsjf:3 angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light fallmf6scr,b 4pj;f9q 7lc s on two 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 the pattern. Determine the wavelength and frequency of the li lsjccfqr ,; m6p7b49fght.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 nm, f+4p3dzq pb ef9alls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the centezb4p q+dpe3 9fr of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and produces an in.xppq yj6)(ozo /) vqfterference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m a xq)( vqz)o.o6 /jyppfway. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes througpi4:q.c,p i8xr6ne pyh two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1qn r46 :i.py8, xcpipe.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength nfhn)3p8r/w 1- rk:a4fkefam 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum at herwfak fk-148fp 3 :nran)/mthe same location?    nm

Water waves having parallel crests 2.5 cm apart pass through tw: ;pil93ujmdlo openings 5.0 cm apart in a board. At a point 2.0 m 9ui3 ;j :ldlpmbeyond 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 plac u r(mvss.*.qa2qj2kyed in front of the lower slit in Fig. 24–7 so that the two waves enter the slits 180a . jq.22 rsm*vsykqu($^{\circ}\,$ 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 forg3 ;rbxlh: ffw tjbn1yx3 ii 7(*y1w9h light of wavelength 500 nm is located 12 mm fnrhix1wfby;3w3h1j: * lt igy 97b( xfrom the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminatedn 0yvdxvz8ga+ nu6 o em*1.l3hqyq)a2 by 544 nm light. Find the distance between adjacent bri u vov y 8qa+1)h20.ze3yg*xnlma6 qndght fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on t6c-8s s(oimg hht+r( ewo 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 fu8,w oz a 7i khttx6ha71+f zj(gyg/2of a double-slit apparatus illuminated by 640-nm light. The cef1g(o6aa8kxy u,7/ +2itg zz wthhj7fnter point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (70gt hcp2a,y0t0 0 nm) exceed that of violet light (400 nm) in silicate tath0 ,c2y0gpflint glass? (See Fig. 24–14.)    %

  A light beam strikes a pip- , 1nn7nb b-zcc7jfgece 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 tw ojn.ovuot( ,7o 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 angu 2wvu6e9cj4 r8da:fr:,qoc30ubqu fglar width of the centra:4 d: uouf3 wcq,9rfrcuqg0 ae vj68b2l diffraction peak?    $^{\circ}\,$

  Monochromatic light falls 12jvs;mx1e 6qhu4vss 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 fallshp49+* byj hg4ux 6bqf 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 450-nm lidnft+ws 6jsg p7fy7x qh58:ne:rt+q5 ght. What is the width of the central maximum (in cm) in the diffrfss wh:d7+q:npq5+6njy5t8txger 7 faction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653m9z585xcz nn eou+y q) nm falls on a slit. If the angle between the first bright fringes on either side of the central maximum9e5cxz8nn)oz qu5y+ m is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diff bbeuj)ous057e 8/avnraction peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589 57e /usbou0nve ja)8b-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the fi+7drbky4 n*o*l ow,r tdtp(.hauc0u1 rst dark bands on either side of center are separated by0tu.,unowdk t*4hol(+ c*1rd7 r y abp 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single slit, w (y*yect27rz 7ff7p fit creates a central diffraction peak thayzpcr*7 77fyfwef t2 (t is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction ma7-jbd xtdl8uh h v-t0(ximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction mau d bjt(l- 0x8hhvt-7dximum for light of wavelength 420 nm?    cm

For a given wavelength ,5jhu)u3enft $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a secor r)dw1y1modtlp; a/rhh) t,+nd-order maximum when falling on a grating whowrp omht ; tdd+))/1ary1hrl,se 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 gux-6l63tyik 5 mfra+ irating have if the third-order occurs at an 18 i+fti6-kym6l5x 3u ra.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 li f3+2yheu-l y 2sczq(rydsz v3zn77 f0ght falling on a diffraction grating is observee2flr+s207n qy(sc7 3z-f dhyz 3vuy zd 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 gratin2-kg02o fi ou f;jhdl*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 normalgk l2e lxv(n a)1.v *iuz6ob2mly 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 that cabi ncyovw 3*khn+/k8 3n be seen if a grating with 6000 lines per cm + *knb338yi/ vkhnocwis illuminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full 2; + ,, q5rl-ctgqps vwhh.fagspectral orders can be seen on either side of the central maximum when white light is sent through a diffraction grating f,-2g 5,p+w taqg; vhrlcqs.h. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm k67y g3mu h0 mygk-i,dto 750 nm falls on a grating with 0u,ggmyk67m kh-yd i 3$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which p)lk 5x 1g6hn uo5-bbomroduces 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 are measured be5jp8v q,-(uf cg*cc)x7dssry 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 wavelength is most strongly)ph5.juzp i c1 reflected at the center of the outer surface when ph p z1cuij)5.illuminated normally 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 plates are eachds v1t s-w5:jrmlim 705r si8s 26.5 cm long? 5is5rtm17 dils:- svm8 jrws0   cm

  What is the smallest thickness of a soap filmgwsf+zc. gn/c p:z (80vw+t ewrrw+4z $(n\;=\;1.42)$ 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 ;8am4ze moazd2c9)5o/ r1zhje rp:zeyellow ($\lambda\;=\;570\;mm$ 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 (n ms-,fitvyisj jw5wp9* po274ot counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens r,fv j jp-p4*yistow2w ms759iesting 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,idwnm,at:- n. m2vz k glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How mnnad t2:z ,mk.i,vw- thick is the foil?    $\mu m$

  How thick (minimum) should the air layer be betl4wf l5q.* qn /fq)scrfi0l- vween two flat glass surfaces if the glass is to appear brigif) q.fq-wcfl *v5l sl/4qrn0 ht 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 stolen diamon; d9dv;;uw0of6;xg zvlpzijq *2vp6 gd $(n=2.42)$ 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 alcoholadceda7rc (vsg ( 3dzc+t88q4 ze8c: a $(n=1.36)$ 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 immersed in a liquid5*: 6tnd yo ghybeca.*qp0s2j, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 coa s.:bh ygt*5qd6c 0j2y*ne pm. What is the refractive index of the liquid?   

  What is the wavelength o92 jyca4 5z,y.afw lt :fx h31n*wvkrbs v1r7cf the light entering an interferometer if 644 bright fringes are counted when the movableb. t7z2f fv1jx,rc n94: wah5wy3kyscv r 1*la mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometeraib1 bvn.z 3/xq.z qsjlv(;+d. When the mica1(v sn blxbv/. dq;q.+ z3izjrometer 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 is 589 nm.    $\mu m$

  How far must the mirro jv36 ct,gxb3qr $M_1$ 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 internc 8oofe5mkfxo: t-+ hl8p( ,xferometer (Fig. 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 pase ,hf: (kn cloof-tx8m 5xp8o+t 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;j8izmvf exx+x5y +dlb ffy,ce(.z 38 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anglecdh5tw0y -q icxd.+wb(p -c(e for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle forbh ;/*bfdi ,vg a diamond submerged in water if the light is hitting the df */, ghdvibb;iamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligneds uwao:zbqnz 1us a18l/ .qi9/ so that the light passing through them is a maximum. At what angle should one of them be placed so that the intensityas1w:8l.u/q/aq bioz9u sz n1 is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the c h4;y+iw tx))ddc9 0xhkfgq:axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light ;c40gxx+ wh9ctd:d qi )kyf )hto
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented /hzq8yf9xym 9at 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 ,wzi kb*fdn* tz4co-0 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 rm 4ypk4iio )+reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflei kr pomi+4y4)ction, 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 sheets, each of +gr z fv00.ydery4vf 7z6t8a/mf .opzwhose axis makes arz +. d 8amz.e6fr f7v zv00y/yopgt4f 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength in zbwmd m8a855poeyfrevo 7 0n,p g)2,kaj* ,$ 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 mountk.zih bf5 *r-eains or airplanes can interfere with the direct signal from thekb5 rf*ezh. i- 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 separa4a(dj w2z,zh )hn 2i*dv/z btzte sources passes through a diffraction grating with ,z4)zn ihb tz j/zdhvaw*22(d $ 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 th;6mek zpc; e.::pth mb2dga. -lt mm7hrough two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wta::-tm e.cmml.pbh; e6pk7 2hm;dg zavelength 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.u*cfdpa )8 :spzj t5e broadcasts from two 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 a5fe*p:c8t za )d psu.js 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 fl:q)2x7z 7gobcd(mu 5r* t lhm wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what an rgc7qfl( x7:) 2*mbdhl oz5tugle(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 a single slit of width D at sudgc)x3.tfml5/0e- v q w x9qa 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle hb u*93z gd 1szxrcv 1.s(8drtqave a series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed .8z 3 u1(9rdvqxd*z1ctsgrb s at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there iswwa flzj 7+rr uy07cp,8 kg. f3r:o2du to be no second-order spectrum07 g.fju 7rl32rafczy:wd p8o,k ru+ w for any visible wavelength?   $ lines/cm$

Show that the second- and third-ord/z+zt s 5m;(;diujfzver spectra of white light produced by a diffraction grating always overlap. What wavelu5t (/;i f +dmjzzvs;zengths overlap exactly?

  When yellow sodium lighk,a ,jb:q rp0ut*yh :hf o0;jat, $\lambda\;=\;$ 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 ho5m e; mrmfv;a9e2)h and the pattern is viewed on a screen 2.5 m from the grating. The incident light bmhr; 5af9mov 2meh)e ;eam 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 nm 99jwaa/ s6;g hhg,jrpk;h ;wpthickness of aw,wrga/kp h ;g99h;sjj6h;p it, when laid on glass, is needed to reduce reflection 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 incident normally on a th chzgr,ziul0:(bb-8a y,m ;c ugag1y 7s+jw8yin sheet of pyucbg m(s0,y:iar-u7yz jw88;cggl1 bh +, zalastic 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 needed fo3q* d wpl31c 59zhfn4ekonr(z r 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-zero) thickness for the air laydjoec:j/t- ;j er between two flat glass surfaces if the glass is to appear dark when -j;ejj oct/:d 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layere9-k6;p -ofmpdsrilj .4g z 6lvd on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describeg.;4om vrl dz-l-f6pj p9s6ki 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 mn.) 93u0t +z b,c bf0qcchkvchorizon is the Sun when light reflecting off a smooth la03fc0z .tc,mqcv +u)h ncbbk9ke is polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polczsensu:vgxid: u -8(l p6g09d-;pylaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after thcd 6(9iy-8u- ps glp n;g0lexv :s:zdue first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets wew d-n7df,6e *3js.m6zpqr l nhose transmission axes are at right angles. A third polarizer is placed between the first two so that its axisez37e6dqr,.nnfm * d6 s-plwj 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 plavikuteb hbs9q(-3e mqy2.xszm5s. 63ced 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 slit of width 1.0 cm and i mah,:vjuaw5 3s pointed at the Moon, which is approximately 38u: a jvm5,h3aw0,000 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 polarizers are each placed at 5n)* gcbm6t ;vv8zkxcuxmv 2 *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 .wvf8*v 011 idnmgcjcuyqy,rm;mh.( $(n=1.34)$ 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 rkx2ds/a;aje7 adiating 6.0-MHz radio waves in phase with each other. They are located atjax ;e27 dk/sa 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 c7h63we m*bq s mv:1ztvontaining two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral pribm3svm v76e qz:1hw*t sm (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 andp5pamhw*o m c-tec2 d4/ na,c. 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