Does Huygens’ principv)hjj+f0l 6dj le apply to sound waves? To water waves? Explain.

What is the evidence that gstxjz(: zs:m3fl*o (light is energy?

Why is light sometimes described as rays and sometimes as wamoq7s6 -jm pc0ves?

We can hear sounds around corners,2c oqniu)1i:t but we cannot see around corners; yet both sound and light art 2:1uiqocn)ie waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, howlrq1 yz/7f+pne w2q28n p9g pb would the fringe pb/e8qr+w2 ppyl1p 2 gnz7q9 nfattern be changed?

Monochromatic red light is incident on a double slit, and the interference gbtby. d (p/ dqy:freax,)(f1pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is rye.tq ((f,xpr1:yf/d bgbd)aeplaced by a blue light source.

Two rays of light from the same source destructively interfereq+3alsoatu)bl ) (fm; if their path lengths differ)3tbml +of;al(s u)q a by how much?

Why was the observation of the double-slit interfe*x-hyelo9ydm.ec u9jh5+ x -rrence pattern more convincing evidence for the wave theory of light than the observation of diffuley -x mx 5.e+- jrh99h*oydcraction?

Compare a double-slit experiment for sound waves to that c 0lsc37l(ycpx72ope b;f 6ci for light waves. Discuss the similarities and differenc yf i273c6(eb7 cspco;0pc llxes.

Why doesn’t the light from the two headlights of a distant car pr 99h aft,u-ljkoduce an interfere9,ahjl t9 -kfunce pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one s*uipshanz rp y)- g;vtvx99:*b .uh f9lit is covered by a red filter (700 nm) and the other by a blue filter (at;*.ugifxhyuhn9 vbp) :-v 9* 9rspz450 nm). Describe the pattern on the screen.

When white light passes throjolzih9 - (x3wmmp 5g,vy u+(hugh a flat piece of window glass, it is not broken down into colors as wpj-zl3,h+5ohx (mum (y9igvit is by a prism. Explain.

For both converging and diverging lenses, discuss how the focaln.j+me,+:nsj13xvru mq 7rjd length for red light differs from that j+dn jr x m u+,7qrms:1j.nve3for violet light.

A ray of light is refracted through thre:xa6so,k nrj1 s 0huzg;dk:(ve different materials (Fig. 24–55). Rank the materials according to their index of refraction, least to greatesx:a,:go 6khsnkdusz(j1; 0 vrt.

Hold one hand close to your eye and focus on a distant light source througg)w 6mks1ff c;l;ci-ccj1b/th a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Descmfi w/-lcgjc;6)t cf1sk ;cb1 ribe the pattern that you see.

What happens to the diffraction pattern of a si6yls 5 ok+adue,n 8fr6ngle slit if the whole apparatus is immersed in (a) water, (b) a vacuum, instead of in aird6as5okf r6u+,yne8 l.

For diffraction by a single ufq i g;:;gsm5 9uuvtga ,9(ygslit, what is the effect of increasing (a) the slit width, and (b) the wavelengtuuf; y: 5ui9 v ,ag;smg(tgqg9h?

What is the difference in the interference phqv/9 nwxt z:fi3u:ng 5 2rzhi6f 2g(lej* y2patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, n+hit5dizn 1.uq q85a what is the advantage of (a) many slits, (b) closely spaced sla1nihi5+5nqz q d.ut8its?

White light strikes (a) a diffraction grating, and (bv;uzuzisl 7u */ rx4o0wbt1w)) a prism. A rainbow appears on a wall jusut4b )7v0rw uzo l /swiux*z1;t 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, jhx(h ;x5 alc6incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacinxhl56h; jxac(g?

Why are interference fringes noticeable only for a thin fi0 u buwy:v8nf3; p i3x3nfl,fjlm like a soap bubble and not for a thick piece of x0:ufbnl 3j3vni y p3;w8uff, glass, say?

When a compact disk (CD) is held at an angle in white light, the reflected ligh-wq(.r; q nw)ut qmcq5t is a full spectrum (Fig. 24–56). Explain. What would you expect to see if mono(wqqruq; w5)m .q- ntcchromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the cxnmw,*1 fxv 3yenter?

Some coated lenses appear greenish yellow why elhp.ql 2s56en seen by reflected light. What wavelengths do you suppose theyse.h pq25 ll6 coating is designed to transmit completely?

A drop of oil on a pond a6plnje. +1nzs;woj( bppears bright at its edges, where its thickness is much less than the wavelengths of visible light. What can you s+ozp wne6j ;jn1lb.s(ay about the index of refraction of the oil?

What does polarization tell us aboud uquzf:ox *12a5gtc3ys+og/fm n w +8t the nature of light?

Explain the advantage of polarizcf67euz+ ,oa cfhj -y/ed sunglasses over normal tinted sunglasses.

How can you tell if a pair oj: gi1.rekp4ff sunglasses is polarizing or not?

Two polarized sheets rotate62 38 umfn+z,h+rbp uglp 1ilkd 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 st4jv/bx* myy76d )c;j xw+swzky if the Earth had no atmosphere?

If the Earth’s atmos9d y6 bj -iq9seic1ev;phere were 50 times denser than it is, would sunlight still be white, or would it be some other colei1- ;vjbq d9iey cs69or?

  Monochromatic light falling on two slits 0.016 mm apart produce5 ;p n3y*pe u2hkqrtg/s the fifth-order fringe 5 *hykq;tgu 3/2pnpre 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 angj*:t e .ok(1n rihco2yle 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 nacr*:pcs-p,0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the patteprpc *n c:-as,rn. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-3;l,q7ik/3ur oo)uh k d9jazlNe laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern oniu/l3u, akq 3 odj9hl7z;rko) a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and produces s 7nu/0(ra( 9og-hpt6 jc eoynan interference pattern in wyo o6ja(gs(/ctep7u0 r9n- hnhich the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apa x:)p vjhazs g3he:wfrv 1dq *be92u78rt, how far apart are the second-order fringes fp:s gv1u2e*erb8:aj39 qd fx )vhh7zw or these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelengthnm61y * 5wj9(. sw0b ll3g zkda5pptxv 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visvxk j s lgm9wn.yt05wb 531l6p(*padz ible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart passis- ix26+dzdp through two openings 5.0 cm apart in a board. At 6i-2ps zdi+dxa point 2.0 m beyond the board, at what angle relative to the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in front of the lower slit in Fiv+xz4 aa;5 alsg. 24–7 so that the two waves enter the sli+sa aa4;5 vxlzts 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 experimentceg+htxm g -/+2ft 8rq, the third-order maximum for light of wavelength 500 nm is located 12 mm r/+cqg2xhgm- tf et +8from 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 nf broyz; ep)0 4zk1c8mm are illuminated by 544 nm light. Find the distance between adjacent br)e ;c 418nbzpyfrk0zoight fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two slitsy)6w :;xg/vu 0vwtjq- cdu:ft $6.00 \times10^{-2 }\;mm$ 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 tbtag9jzy *,(7 j( hhj(n=1.60) covers 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 ta(h7 *t tjy 9gjbz(hj,he (minimum) thickness of the plastic?    nm

  By what percent, approximately, doelxgmc.065pchx vnpk3(v7s s0/wi lbdr3; hq: s the speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fig. 24–14.) ppgrk05ivv;sxc 6 7c3h0bl.mnl(h xs dq3w /:    %

  A light beam strikes a piece of glass at a 6 s-e q4-h8yqrl0.00$^{\circ}\,$ 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 e;gnu8h/a m3fmm4+ f zwavelengths, $\lambda_1\;=\;450\;nm$ 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 spjcn g;np:l;g7i3 97 ybjm8volit 0.0440 mm wide, what is the full angular width oloi j:y739ng 8jp;vc; bgpm7nf the central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that ispmt jq3j 9ui f+j*5r.k $ 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 faltra2evp0nui -nb;h 69 )zc tf,ls 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 d,xt ot+6 2znl+ggcx23j j7eewide is illuminated by 450-nm light. What is the width of the centtt +2e6 +g 3jdg o,jxzxl27necral maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If thk-*mti m)(m lu w8l;nhgx)pze2.9dbhe angle between the first bright fringes on either side of t2glum*9tdn )mh(x ;p z kwlebm.h-8i)he central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screenn2:u1tkzg66nx8jw 6 cb:u yel 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm lightz n ug666u8yex1:2b ntjkl: cw?    cm

  When blue light of wavelength 440 nmb ay-0*gacmw*. 1ta.xdrd r9n falls on a single slit, the first dark bands on eithe. a a*a1r dcx.rywd-ng0mbt *9r side of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a single w 7d*qv8t-eoj6jht0 b slit, it creates a central diffraction peak that is 9oev*t78-q t6hwb j d0j.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 diffractihl)mf nc6qh 0mvpp/.6on maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?h/ 6h pc)m nplmvq6f0.    cm

For a given wavelengxyy h,, j:, h-1sje zqcl8smp,th $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light prdka25 o)b-b t-*v k)+usxm n hxcm1-wxoduce a second-order maximum when falling on a grating wba2x-*cxs5dkmu-w hvn ox+b -)m1)k those slits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a grating havkh*nsf:o,y (o-ok / gve if the third-order occurs at agookv ,/f( ksyn- o:*hn 18.0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

  A grating has $8300\;lines/cm$. How many complete spectral orders can be seen (400 nm to 700 nm) when it is illuminated by white light?   

  The first-order line of 589-nm light falling on a diffractio::*xf( rv/sj kpckn8 qn grating is observed/r x: (f*qscnk8:pkv j 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 .t: zbnx8q0uvo; +vjkhas $ 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 on aazd62i lno2 4 *ryf4wb $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order that can be seen if a grating with 1jjc.:wmjbn f 5-r9v h6000 lines per cm is illuminated with 633-nm laser light? Assume normal incide-hvmw51n9 jfb .jr:cjnce.   

  Two (and only two) full spectral orders can be seencma7rovq3s +/ .yz ;an on either side of the central maximum when white light is sent nc;3q sa7 .az +rmy/ovthrough a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelene: yx; , :ihefi0jn hje:40pspak.t i(gths from 410 nm to 750 nm falls on a grating with kshi fanp 4 ji:0:p;ey(tj e,:0he.ix $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces mo 983zxg6 lisginochromatic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum lines are measured by a 7-p5wgtzd44 ffpug )y $9500-line/cm$ 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 reflected at 1 dqlen1v,1rxm: + tohthe center of the outer surfr+,1onle1: mdhv1x qt ace when 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 ifpwh)a9j *0i 1rucpcm3 the glass plates are each cwpu jpi0)hr1*39cma 26.5 cm long?    cm

  What is the smallest thickness of a soap film h d*eq*hsq-z9$(n\;=\;1.42)$ 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 yel ahflz95zka w *,fo:7flow ($\lambda\;=\;570\;mm$ 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 ;;wi.uumnq7,e0 xr idpl x ic +s+(;vncounting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lensxxwrni insu;vl+0ie;(p 7.+uq, cm; d resting on a flat glass surface (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of tw ly2x ye-53mqk(j- .r bzq,ybco 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 thick 2z5qejm ylxbkryb.(q,-- y c3 is the foil?    $\mu m$

  How thick (minimum) should the air layer bf9r;d4dd 9i ame between two flat glass surfaces if the glass is to appear bright when 450-nm light is incident normally?;ddfr di 9m49a    nm
What if the glass is to appear dark?    nm

  vA piece of material, sutlaxgr8df33ur46 mk8 spected of being a stolen diamond $(n=2.42)$ is submerged in oil of refractive index 1.43 and illuminated by unpolarized light. It is found that the reflected light is completely polarized at an angle of 59$^{\circ}\,$. Is it diamond? ----待选择----yesno 

  A thin film of alcoh08kqidz7s 4 w mqbm*8,nxwn1dol $(n=1.36)$ 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) kr:oz8cxfgwp/;63r9x;f zb3g 2gcsw is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. Whatwb:2;r;f3gzfxpw/ o rgsc6cz839gxk is the refractive index of the liquid?   

  What is the wavelength of the light entering an interfe6cl* wboz v6bd gty2,(rometer if 644 bright fringes are counted when the movable mirror moves 0.225 c6v* d6bgtz,l 2wy(o bmm?    nm

  A micrometer is connected to the 5b zd+vxed z/-5.inntmovable 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 tdnie+5xvzzdt- /b n.5he foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirro5 wr)rj; i qmn:0z6ahbaxi.b :r $M_1$ 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 throughuf:3 skk (ns.nh(s(ig. i gw*n 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 l*ki .:( ng inh(usgsw3fn(ks .ight 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 6gy4bqo 0q 41dm5$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle,qh.ulpc9ihc x 9bk082 0dormiuj24 3ok8 dzz for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is hittini 9n(hw+kb3 ing the k 3+ 9iwni(bhndiamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximum.4(h 0bebrfo zom:/ d8g At what angle should one of them be placed so that the intensity is subsequently redubbo4ezhfg/ ( r:8d o0mced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to r1oh b;k5drvv) 7x .-nsqd ve.seduce the intensity of the inciden r7kb-.ev hs;ox.d5qd sn1 v)vt unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are os6zt 7 u3z0kgo6jx nb:riented 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 atnrf 9 tjl)8p2+u4d( xmv kz6wd 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 ofi qgv7ehk/0zr p8b t)-f the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from ab8v gzh0tie-7 pbqrk)/ove 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 througlby 5)mcvh6 rhpt-, l:h five successive Polaroid sheets, each of whose axis make: ph6-l5)cvm, yrbhtl s a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength xq ;p87k pgaoy7qk(f-$ 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: u b,dbj --.lrd;1zz ilkml/z from mountains or airplanes can interfere with the direct si :/-d1r;,zu.ij-k lzbz mlldbgnal 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 sezo: rue8/(1-v8df,idln fuykparate sources passes through a diffraction grating with kfno8l(y riez/ud : 81 fv-u,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 passesji59h3frnh(pb0ru nl zk3o ./)oo or7 through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces it .o foi hjuh03znor3p(b/r79o5l)krn s second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from twoow*pug dl1cc(fc c;pt 96qt+/ 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 tqdgptl 1w9c c;ucf*t/ 6+ cp(ohe 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 outsidhw;9etg / mfk1e doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(sm fwk;19ghe/t ) 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 sliav0s6 ftm. 2wgt of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain b/)61kf5i aab3rb fc k84kbmgyeetle have a series of parallel lines across them. When normally incident 460-nm light is kgi a 8kb4b/fm)r1 a5by6ckf3reflected 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 must a grating have if there is to be no sd,;qzdhmq,b p 5c7cu :econd-order spectrum for any visible wave ,;cqdhm57:, udpb cqzlength?   $ lines/cm$

Show that the second- and third-order spectra of white light prod5c .eev:dgx 11r fv,druced by a diffraction grating always overlap. What wavelengths overlap exactly.:d e r cvev1,xgr51df?

  When yellow sodium light, v( 5tp)w 5upbq$\lambda\;=\;$ 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 patt0;yky;bafj 9 y ovdoby2e2 j,:ern is viewed on a screen ;kbo9ydvajy: o2by,f0j ;ye 22.5 m from the grating. The incident light beam consists of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of r9.-eqzjji nd8 l it) /hku,yt7efraction 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 when light of 600 nm is incident normally upon it? Do you have a choice for an azt8lk /-djune9tyi hj ), q7i.nswer?

  Monochromatic light of variable wavelength is incident normally on a thin she-fz(q;vv o/beet of(qve;/ bz fv-o plastic 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 for annwn3,wfa e yvy7 dj+;+ 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 layer betweg/-xbswfdktm ( 5 o/lg p4/t,gen two flat glass surfaces if the glass is to appear dark when 64/o tdx(/fgkm , w/b4tpgg5s-l 0-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light ol0thyz+: (z f/kzrfa a6b06w transmitted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative sizflrf ktwyo /b z:za6hz 60a+0(e of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when:/wkrt /z3d gd(i tct1l ,0m,ddqol 9n light reflecting off a smooth lake is polariz t/:,9 gn10mtdw,rtdd(kql 3z i/cldoed most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the w(bxjq5v-6q 0ah (d /6jonlh d3wyr6 kintensity of the incident unpolarized light by an additional factor (after the f6- / 6xoh0qj3nahb(vjlrwdw q(d y 5k6irst Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose tra:hm0z;f 9rxwnnsmission axes are at right angles. A third polarizer is placed between the first two so t:mh9wzf0rx; nhat 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 vertical, a w/7f; mtw)5xv4i rdect 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 pointedur68xff(wegg, h g5auxph/ku20y :v 0 at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam wf0 u/ryk 2xg:h6f0 xgw,v8(puue5ahghen it reaches the Moon.    km

  A series of polarizenj+9 l-dnv5wvz ktpp yf9.2:brs are 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 gynqxc:q9yb;6 ;jh1 x g 8yqs6$(n=1.34)$ 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 wav*.1 f ig/ t6jkc+wtv3j3zkri by8 bf1mes in phase with each other. They are located atw j jry 31 /*.zf6k1+3 v8gmikfitcbtb 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 and 650 nm, entw(n)x*coe t 8ku0v1yx ers a sv1*)ux 8( yecn0t okxwilicate flint glass equilateral prism (Fig. 24–58).
(a) What is the angle between the two beams leaving the prism?    $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with    $^{\circ}\,$

  A Lucite planoconvex lens has 5sbsbv n+0/heone 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