Does Huygens’ principle apply to sound wak ak.:n .qm7ymd5z; dmves? To water waves? Explain.

What is the evidence that light is energq)c:tm0hg /hg y?

Why is light sometimes described as rays al8tzqcbb)n).69a yacb1b de 8knj 9e- nd sometimes as waves?

We can hear sounds around corners, but we cannot see aorrj.)vy 2a,f qz3i:,0cjiuxib 9 rk3round corners; yet both sound and light are waves. Explain the differeyb:z 9iu r,.,3xc r20kfjirq j3o )viance.

If Young’s double-slit experiment were submerged in water, how would the mjza fz a0;7o1b8h k8ofringe pattern be changedzoozb j1k8a7h;8f0 a m?

Monochromatic red light is inciden2c8q/frxw5 r7spy; 9o5yg.zem lj j0ft 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 r5l 8s.pfj2x;rcr5 woqj yzfm97y0 g/eeplaced by a blue light source.

Two rays of light from the ck7* k)e7dy+oghyj q.same source destructively interfere if their path lengths difd qy7 okh.k*cyj e+g7)fer by how much?

Why was the observation of the double-slit interference pattern ovhxkz :4 3l(fc pu-9qmore convincing evidence for the wave theory of light than the observation of diffractixq3 -9pf zlh(u:kvco4on?

Compare a double-slit experiment for sound waves to that for light wave, t,tx)cuna8 js. Discuss the similari jt,cu ,axt)8nties and differences.

Why doesn’t the light from the two headlig bqh 0)ra./l,c gz5* xnp ljce;xwl3*chts of a distant car produce an interferena *cgrw3lhcl,xz5/xl p;) e *.0qbcjnce pattern?

Suppose white light falls on the two sliby yo:w q53t+wts 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:53wy+ tybq wo pattern on the screen.

When white light passes through a f-;2hx) nlsr txwd9l4qekwg-p+ s 6, cilat piece of window glass, it is not broken down into colors as it i+n6qi9 ;-tsk4-rgdecxs)2lhwx lw ,ps by a prism. Explain.

For both converging and divepmv.gf +8t3kn* cu c+lrging lenses, discuss how the focal length for red light differs from +u *vl+cpmt .3fknc 8gthat for violet light.

A ray of light is refracted through three different materials (Fig. 24– ;v n7zgwgawfx.)vr *755). Rank the materials according to their indexv* zw7nxv. )ggw7fra; of refraction, least to greatest.

Hold one hand close to x :rh2lg3f jj(mk4o ,kyour eye and focus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattej(,khoj 2:l 4krfg3 mxrn.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if+r0s l(f ) 6fnjqq:r;3db ekibnu tg,- the whole apparatus is immersed in (a) water, (b) a vacuum, insteaddbi u r,f-;jqt:6(nlrqsn k3bf+)ge0 of in air.

For diffraction by a single slit, what is the effect;drut 8b0*sjodawi4 52svkkx-r 8p z(l q)rt1 of increasing (a) the slit widks( p-t2j) * dt48ikwd;s1lr zqu8a5xr vb0orth, and (b) the wavelength?

What is the difference in the interfereniv(rv;65ijr+obr cx se d+36fce 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 qd: i/iz bt1v69;qhwy)nu ;x*o*mcbm the advantage of (a) many slits, (b) closely spaced slits?zt/b;cm;9)inod6 h*yxi m :vqbq* w u1

White light strikes (a) a diffraction grating, and (b) a pris 1gbsteo7 4avf;1ry5 tm. A rainbow appears on a wall just below trse fyagtb7v5 o1;1t4he 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 700b;r mznx04 7fo nm, incident normally on a diffraction grating, for what orders (if any) wob;0zm7nrx4 o fuld there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for t, z xf:l)*1iri:cm4) txkvwu /l( xcaa thin film like a soap bubble and n)x lf irk)txm 4,:t:liv1cc (auwzx*/ot for a thick piece of glass, say?

When a compact disk (CD) is held at an angle i o8)m/i-63z zp dvhfcqahkb72n white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was 36)ah op72-bqmf h cziv/8kdzused?

Why are Newton’s rings (Fig. 24–31) clo *,nyolnx51yxymwq upn/-6ye v 9h*fjmd:v+4ser together farther from the center?

Some coated lenses appea8(bom0.* 7ii) lb4r vqwf;r cpb9gbaibt*0u rr greenish yellow when seen by reflected light. What wavelengths do you supposlm9 qib .piorf v0b)b*rab 0(;ur b*ct47iw8ge the coating is designed to transmit completely?

A drop of oil on a pond appears be:tyyfwjzx c0a6 pfe-- /td +8right at its edges, where its thickness is much less than the wavelengths of visible light. What can you say aboute8ax-dff e pz/0tjy+t6 :cy-w the index of refraction of the oil?

What does polarization tell us about the nature of light.gvas6r dsg:flw5t 6wk0j x3+?

Explain the advantage of polarized sunglasses over . gddm7jt x vxmz :1inlw (-40z.xp3ewnormal tinted sunglasses.

How can you tell if a pair of rjkym fn.y,b6 yw(e80sunglasses is polarizing or not?

Two polarized sheets rotaw /mn9u0;mfwgted 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 E2oav x( v)y ))t3qe4jwfe(lsriv+b. larth had no atmosphere?

If the Earth’s atmosphere were 50 tz,2 qbdi 4v7aoimes denser than it is, would sunlight still be 7v iqb,2odz a4white, or would it be some other color?

  Monochromatic light falling on two slits3gwx d da(sj-,7fop7j 0.016 mm apart produces the fifth-ordersfgo,j- dpj 3 7(wda7x fringe 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 observeue9;pk)m 21 im/ somzid 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 slits 0.048 /i)gl5fj4q o3sbx2 kxmm 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 lisbogfx3l kjq/ 4 i)25xght.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser *iz j9 7c8y-dvsjgn.6s ow-sh, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far a-wvhj* -sds on8gsj c.y7z 6i9part 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 slit+r:uk:vzq*c7lrff5p n 7 e*ays and produces an interference pattern in which the fourth-order fringe is 38 mm from the r*fevpz+ 7 7k *:yr:ucql nfa5central 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 two slits 0.58 mm apart, how0d;a+o cip q ),m06qkvqlh e3 (ja4hgn)*iz et far apart are the second-orhg aqe zpo0 (qhla ,3j6ic) en+*)q 0t;kvmi4dder fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found t9ivdm:jkd u2, pmv ,b6hat blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. Wha k du,6mm:id9vjvpb2 ,t wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests za t,wosx )/33w1rbps2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle rexsp1b 3) rstaw/,wzo3 lative 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 9*l+ah5zrx(r jpv6ge vqyt5 5slit in Fig. 24–7 so that the two waves entg v ahze+qj r655*9vyl rx(p5ter 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 maxi nnl w.lxub/i.hz(m+;q j:k,l.6l l rvmum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. L bil,uz(;6. lmlwn+q/k lr.: l.xhjnvight 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 1d)4mqp f ok74b.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the slit dqfpbmo7)44 ks.    mm

  Light of wavelength 7.khes+ yt ki9480 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) jb f0 -z+6ww)+bo hnnncovers 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 (mi)w6nz fjob+0+w nh-n bnimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (0 te0tluc9 6,c/frfyv i i8p6u700 nm) exceed that of violetpvlt eii80ufr69u t, cf/06cy light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 60.007-.c35 xe xleuagz6 box4dd6w$^{\circ}\,$ 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 containinr8xoi4r-il -m g 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 angulab43p;cr8rk f zy owq+9r width of the central diffractq3+rbproc4f8 ;ykwz9 ion peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that 8l.3r jwur qaccs+ o55is $ 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 1u37g+ ic4od/jov glesz14a vnm falls 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 light. Wrsv1 3l;h- 0d zv8iy/*shdpvihat is the width of the central maximum (in cm) in the diffraction pattern on a scree; *v1ds -vizh il yrdv/s0hp38n 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angle ba f6hs3w:mp 7g8vllr 06q u(agetween the first brightfm 0lr (7pahw:63sgaqg8vul 6 fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a scree(5vg 2m+dgb f 6hw ul7 tw1j3 pvw(-n-ke(vwbwn 2.30 m behind a 0.0348-mm-wid(uhv5n gglfwp 7e( 2b1wk+36d vtww v(-mw -bje slit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, f 6;g5i,u6xoliom ail ogmdwy//s9 ;0the first dark bands on either side of center are o0o yl6m; lxi 9idg5u/s;giw6o/ af,mseparated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 4zi ,nr mlt 43ni0xz.ah)yv,use,7p ;c15 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a scretiyzinelchsap m),r 7n 4 .x0z;,3 ,uven that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650:chx/ jhvk4a v)9f6ff-nm light so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width ofjxv c )kv9f:6h4h/aff the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengthsaf9 0)gdz h1xd v,h:y $\lambda$, 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 maximum when falling*m-wc;hmja i iiy1 z z7,s+x6i-pq c5h on a grating whose slimzayicw5+ * ;61,-s -pxjhi zqhii 7cmts 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-or dy28 kilf:zk,der occurs at an 18.l,kfz28yid : k0$^{\circ}\,$ 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 falling on a diffractiont2 jt5t +i*zlp grating is observeij*t5t2 zl +ptd 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 )zf)f(c : tn.4 yozhhk64csjxhas $ 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 ondxsz3 4h( nho 4ue+4vo 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 wit8fx h288vw z4ltc(i) m3jq lg7:x kvyyh 6000 lines per cm is illuminated with 633-nm laser light? Assume normal iyvywcl4xz)7hkvxlji3 882: 8 f (qm gtncidence.   

  Two (and only two) full spectral orders can be seen on either sidd30t pmnrm.p u u),1j7bfd *cpe of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the gratinmud,1urj . pnppd )7bmt 30fc*g?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengk/g)w -)rb 1y,syf vqkm5pp2u1tmkh ; ths from 410 nm to 750 nm falls on a grating withh1rm mqwvy btkf;uk)ypk p1/)5g -s2, $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light of a known wav3i s9e di 7.uwz, sa7egk+nzw.elength $\lambda\;=\;6.328\times10^{-7 }\;m$ 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 spect.cn;f6 ;skne+k1iu j xrum lines are measured by a $9500-line/cm$ spectroscope at angles, on each side of center, of +26$^{\circ}\,$ 38$^\prime$,+41$^{\circ}\,$ 08$^\prime$ and -26$^{\circ}\,$48$^\prime$,-41$^{\circ}\,$ 19$^\prime$. What are the wavelengths?
$\lambda_{26.72^{\circ}}\;=\;$    nm
$\lambda_{41.23^{\circ}}\;=\;$    nm

  If a soap bubble is 120 nm thick, what wavel7js1q r d-vttny1oj2 ;ength is most strongly reflected at the center of the outer surface when illuminated normal7trdo2q ;vt - nsjyj11ly by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Exam. nl a 4hh.d.a7g3tm ijbuo8+jple 24–8 if the glass plates are each 26.5 cm long? jhaag hn+3d.m.7b. to4 ujl8i   cm

  What is the smallest +,:x undisjxofczqqg3qu8n :/ tz:*) thickness of a soap 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 ri5h.d))-5jly) -ckrslf xs o($\lambda\;=\;570\;mm$ 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 rin24epjdrxl/ omsz1v.blsj4 +9 giu40p gs (not counting the dark spot at the center) are observed when 550-nm light fjdu4x44v2pzlel /ss mob+pgr9 0i .1jalls normally 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 sep6 7afpjg6p:u yarates one end of two pieces of optically flat 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 thicfpy6ag:67p j uk is the foil?    $\mu m$

  How thick (minimum) should tps-n 7uw.q25uyfsm,9/gbsec he air layer be between two flat glass surfaces if the glass is to appear bright whecs5ysu9q/2 pw, m-7gebnf .usn 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stefg1xuic 8x, .olen 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 fmja(-fu ckw*vu e686ol $(n=1.36)$ 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 liquid, the diametc l 3hfw/e:d)zer of the eighth dark ring decreases from 2.92 cm to 2.48 cm.)wcd3/z :lhef What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if 644 bright frifqus-3 nj;q u2jr,7s jnges are counted when the movable mirror,f -u rj73s s2nqu;jjq moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometep; -6yhfz/5f cvkbr4 xr. 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;f v-p hx45bzcr/kf6 y the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirrusyl;3+)sd),q x qddror $M_1$ 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 throug*y 6x3hcn7 jrjlj*9jm h 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 refractijjr7ny l*cxh 6*jm39jon of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are ori0r;rm /xs;ko cented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle f vcqm1hn1 br5(or an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angleci:zt w i3g+jq:b1- :r t:ttzy for a diamond submerged in water if the light is hitting the diamongt:i:-z:t3t: ji1cy +brqwt zd $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them isms-+typ ox f(: u5sf.d a maximum. At what angle should on.s:fmtpfs+ o (xdy u-5e of them be placed so that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes o5lj e55ucvqp,f two Polaroids be placed so as to reduce the intensity of the inc55 ,lpq cje5vuident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orin9:k:uelu +p4t9 altpoqd g wd8,hc,-ented at 40$^{\circ}\,$ to each other and plane-polarized light is incident on them. If only 15% of the light gets through both of them, what was the initial polarization direction of the incident light?    $^{\circ}\,$

  Two polarizers are oriented at 38.v8lh/+e1hl us i+f )vi0$^{\circ}\,$ 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 ;+o3gwg vwhgik6y * 2sthe surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brshigy wvg;*2 ko6+3wgewster’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 whos 1,ux 8dw x4;apb9eb;g4t godze axis makes d4;up19; ab tdx84g,e g woxbza 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength mjvip)nx -pul3*38qb $ 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 fq -:bzg .qi,db,6hvrgrom mountains or airplanes can interfere with the direct signirg:zd bgvqq, -.6bh ,al 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 diffraction gratingh39h; msgb3pouw5br 3 with br;hwb33s9o5ghu 3pm$ 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 pas-ot5 h-f48:y+s j28fu0 e i1 wj zhx/ufhmpkfjses through two 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 tj-4 ehy10w j fozt muf+s-8f8uxij2:5f/hhkphe central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operatiy2kw-k )/rer4qg8ia hlwl2q* ng at 102.1 MHz 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, perpw)lrl/*ir8k ae2y-k wh gq24qendicular 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 welqd6f slv;z xxaom42, 65 7mwfcl back from an outside doorway 0.88 m wide, 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 ,c dz5flfv;x64 s mw2qam76oxthe playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of widtm,71fvvkx ta 86a7wixh D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of paralv et l.r+hk(/clel lines across them. When normally ih(+/c.lkr et vncident 460-nm light 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 centimeter r7asp;w3s , agl,n.iov 7n1e wmust a grating have if there is to be no second-order spectr ,7on1salnsv p7,gi we3a.rw; um for any visible wavelength?   $ lines/cm$

Show that the second- and tv+ ,y6;cf )r 5jlwgitxhird-order spectra of white light produced by a diffraction grating always ovecr;tijw fl 5v+6 ,)ygxrlap. What wavelengths overlap exactly?

  When yellow sodium light, yf*1ohno/if9v eaye/ ish 7svqf89 -2;) iiho$\lambda\;=\;$ 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 an pd9 wlr/,pxl*ceo7-z kkk4x2 d the pattern is viewed on a screen 2.5 m from the grating. The incident light bewk7z,pc/kd 9x24ekp- o l*r lxam 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 refracjxl968n4xagfjy 4;t ;*wlgq rtion of a clear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero whe ; tf9nxy8xlgl *;4jg4raqw6j n light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variabl encti1.tblm7ib60e 2 e wavelength is incident normally on a thin sheet of plastic film in ain 0ite6b1le2m. 7ibtcr. 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 thickfojm1ar-( go (1ttl ,tness needed 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-zero) thick3 ej-sumro6naqu1, - dness for the air layer between two flat glass surfaces if the glass is to appear drm6oqs -d -1 ,ujn3uaeark when 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 h*wf*suqwar,3 bj d/- film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all poaf ,*h3*jb /dswwqru-ssible 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 my+et 8upg5mmtoi 5m-2e7h6m 2px0 dt Sun when light reflecting off a smooth lak7t82putm ehm0y5gxmmd it5eo6 +2pm-e is polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as ty4.lk:dilq ,j9gx nu33k*c7lqx0fgg o reduce the intensity of the incident unpolarized light by *4fuxg3g:q73dl. l,9kn lxk qj i0cygan additional factor (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 emz60ya8wa kko23x, 8r i1jwpaxes are at right angles. A third polarizer is placed between the first twp02akry w 6 8aw8x3me,o1ikzj o 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 their axes verticazqf6z wl 9 e1im:6z5hll, 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 an2ayn1( 8aanzj d is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume then 1y aaan(8j2z 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 arr- j zcp+ec3v l)im5y)e each placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap txzi.pmj7p8pm 3:rs0 $(n=1.34)$ 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 radiatinr npx;lz p9hb(1gly+; g 6.0-MHz radio waves in phase with each other. They lb;g px1h( rz9lp+n;yare 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 light containing two wav *r+n) :u;8,qkvitw8wzz)p ,an,z lx 4pr fvbpelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral)z)p w84zu ikfza:wb+nvln*tvp x;,q prr 8,, 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 fbv77tx,u(r6sd 4bit o. 5u zalens 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