Does Huygens’ principle apply to sound bdwjfkp5ntv*y2 )9z9 ak*cwdq (x90ywaves? To water waves? Explain.

What is the evidence that light is e)/xxkuh ev3 sgv(f3v: nergy?

Why is light sometimes described as rays and sometiwo m7c ;9x6akp;afl7r mes as waves?

We can hear sounds around cornersq tkbxezhu f+r5+1 x*9, but we cannot see around corners; yet both sound and light are waves. Explain th *+r+9ex5 tubx1kqhz fe difference.

If Young’s double-slit experimdg-3hjj 39gv6szgag 3 ent were submerged in water, how would the fringe pattern be chg6-gh9 dj3gz 3jas3gvanged?

Monochromatic red light is incident on a double slit, and 2p: s1otati lr wa h4++z as34v,kx9ujthe interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light so9a3tlvz2t+uoa1k 4:h,+ax4 ws pr ijsurce is replaced by a blue light source.

Two rays of light from the same source destructively interfere if their path le )rm c0n:7zegnnrmgnz0)c: n7 egths differ by how much?

Why was the observation of the double-slit interference pattekb67urjl ;sve* y5c v-1ktvti6 /wv.k rn more convincing evidence for the wave theory of lig;/ k v sc 5w vv.u-t*ty6jri7lbvkk16eht than the observation of diffraction?

Compare a double-slit ex9x;l9qgpcrr9)c v bh8 o8xt7u periment for sound waves to that for light waves. Discuss the similc8hqr 9 c tr7o)xu9xp;9 v8bglarities and differences.

Why doesn’t the light from the two headlights of a distant car w ocs(l1msd m.j f51tj -6lxc6ia(fr7produce an interference patterr66x5 icf(w-1os(j7sm1t. mf jdca lln?

Suppose white light falls on the two slits of pe l ./ns3yez*pn+ 2hy/a8uio Fig. 24–7, but one slit is covered by a red filter 3yp/l8+*e i n.ypush 2ane /zo(700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a0v6po ( tz5pla flat piece of window glass, it is not broken down into colors as it is by a prism. Explain(0t5app v6 loz.

For both converging and didc r396tm 3i5(picp arverging lenses, discuss how the focal length for red light differs from that for 3r3pia(t6rci pmd 9c5 violet light.

A ray of light is refract-:,;m spogvjm8 9r alved through three different materials (Fig. 24–55). Rank the materir9;s: ml 8ov-jvgapm,als according to their index of refraction, least to greatest.

Hold one hand close to your eye and foqvm 3c**ktab:ud t) (tcus on a distant light source through a narrow slit* k3bu( t) :datc*qvmt between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single asq *h7yz tu99u3ty5hslit if the whole apparatus is immersed in (a) water, (b) h5zhst 9*a 7yutq9yu3a vacuum, instead of in air.

For diffraction by a single slit, what isq 3, -rsrpzo7x the effect of increasing (a) the slit widoz- xr,7qprs 3th, and (b) the wavelength?

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

For a diffraction grating, what is the adcv6ki;jtkn8yml kph ryz0 d.cg 036)/vantage of (a) many slits, (b) closely 0 6.gdpty )38mzck;l ihn ryjk0vc/k6spaced slits?

White light strikes (a) o . vkksw323fqmgfv:*a diffraction grating, and (b) a prism. A rainbow appears on a wall just sqk3v3g: f vmw*.fok2 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 7009 fi;38iipwj- wrs3k):lvss l nm, incident normally on a diffraction grating, for what sv)r;p 98ii jlkf3-i l w:ws3sorders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference frow sntm07hi3+w/vm 3tinges noticeable only for a thin film like a soap bubble and not for a thick piece o/ t+n3 hstvwmi7m 0o3wf glass, say?

When a compact disk (CD) is ggtvomr2 q:u m: ri,r.p)z vy:*b*y ;fheld at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?*grv:bmy rrpzmv2* .:;:yu, f oq )tig

Why are Newton’s rings (Fig. 24–31e4qxdzi3q/ 3p cz)m2e) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. W;* cvq0-w fzblhat wavelengths do you suppose the coating is designedf c z;-v*w0bql to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thiuul-zhf 3b9c oqi(o- :ckness is much less than the wavelengths of visible light. What can you sahbz9o -o3- iuc (uqf:ly about the index of refraction of the oil?

What does polarization tell us about the nature of lvb u)*tw3jg8rtbb1 9u9tr *xpight?

Explain the advantage of polarized sunglasses over normal tint 1eilk ium( e1r0iy8e8ed sunglasses.

How can you tell if a pb* j6tt:itwbj 32 atuc/x,b5 jair of sunglasses is polarizing or not?

Two polarized sheets rotated at r 6ts -f00nlhm)svgc 9qm fw*4an 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 Earth haxnxf3f.z np ,hwk:m/ 4d no atmosphere?

If the Earth’s atmosphere were 50 times denser than it is, would sunlight s 4a swkev )p.)y/x4fzstill be whitss)zp.vae /y)wxk44 f e, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces thewn :hxu1 /az(f fifth-order fringe at wf(h1nuxa z :/an 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm 3 ra2e*d cng kcbh9;j(light is observed at an angle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two very narrow slits 0.048 mm ap3sx -9vysm m. :k tok8hwjxm,gsi5/ 6part. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center :pk w.x9m3j6-xh,mk ioyst5 ss/vg m8of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne lasvev 8 kujrq;v+,bx(-gj(6p kyer, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are theqy6upv+8x,(r k gj;vvj(k -be fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two slits and produces an interference pac9x +lfki6c:;zy ( jd d+eah3ettern in which the fourth-order fringe is 38 mm from the zake6hf+jde( +xi c3 cd l;9y: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 passescm4apon vfv 8u:j/d7m dl ):3j through two slits 0.58 mm apart, how far apart are the se jo a lnf8jd vcm34/vpm:ud):7cond-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit exp )hkb.;rb;m vx-p-cq deriment, it is found that blue light of wavelength 460 nm gives a second-order maxk;qvr-mxd ; -) bbpc.himum at a certain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having paraah +.y4rz :irx-/5uu*hnr h8l46 ergzq n1u zpllel crests 2.5 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 relative to the “straight-through” direction wz4y.*hr4-:lu z qh eu +a xrn6i8rg5pu nzrh1/ould there be little or no wave action?

Suppose a thin piece of glass is placed in front of then)z.5qp,th ,h. db cza lower slit in Fig. 24–7 so that the two waves enter the slits ,.h) hc5pzb,t.zan d q180$^{\circ}\,$ 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 for fbd-6 4ltb ug-light of wavelength 500 nm is located 12 mm from 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 willdbft-4ug l 6b- the second-order maximum of this light be located?    mm

  Two narrow slits separxfv0 xk .w;uva(poqn-.9aqp(ated by 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the sa(ox9qu0wfqkapv. xn p-v.; (lits.    mm

  Light of wavelength 480 nm in air falls on .wm whkn* obsm7+b4,w.8eqrf 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 plasti lphd937 hbtz. tix6:mc (n=1.60) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screttxm:h3h67l.b d9pzi en, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed nsf293g)be er9 db sjrmtisx(0 vy*-5of red light (700 nm) exceed that of violet light 92*gixme-fv9nr 3r tj sb0y)d(5essb (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piecez2;gdzl a2y0t 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 lighkqec f4x+xz; e2bz:8o hvuj- 5t containing 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 ma( 3y+qawz,uuouh:. the full angular width of the central diffraction peaua,+y.m ow zqua h:3u(k?    $^{\circ}\,$

  Monochromatic light falls on 8 wvn1ao:ks6 oa slit that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength 520 nm falls on a 0 js i) (009yxrf:pyfqxy:wn+e:kk js 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 b,gfir7a3z x,3i 1f jm uel rr)m4+-es2czr xm*y 450-nm light. What is the width of the central maximum (in cm) in the dif27 mfuir+rjams1 x ,l3 3) zec*r-emzx,firg4fraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the anrwyl :u0657vs2h e hoagle between the first bright fringe2ays:vo 7hhlw5eu0r6 s 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 screen 2.30 m behind a 0.0388vj9py omfgr0fc62 i 48-mm-wide slit illuminated byofvr9pg 86ji cm2fy 80 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first da o)eur6gto/2wwll0( vrk bands o/ etglo6 r2lo( wwu0)vn either 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 falls9sd*dd sz;or27. kebx on a single slit, it creates a central di b7 2s;zo s9.*rxdddekffraction peak that 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 9xasqb;:o f6q diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what wofqa;s9 :xb6 qill be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength n+ k 0dt*42wvotw ebf/$\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-orderrk;g9z7x2k.qtoz3ii u qm v: : maximum when falling on a gqk:3 xi ;qu:zg o9zir.kmvt 27rating whose slits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

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

  How many lines per centimeter does a grating have if the third)ha,;gd7 ulqz1vhvhn 9dn 0y 2-order occurs at an 1hz,v2;hd u nqvg7any190 ld)h8.0$^{\circ}\,$ 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 58juds vt ky s)vpc61ysjf x,s/-t*7o :*9-nm light falling on a diffraction grating is observed at a/jsf k 76)s *1t: j vtd,x-*ycvupsoys 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratin6ozbp -gkjm b z38 ;xox7q -;yty8( sx0-aivvkg 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 normally26-sqoj j9ou7/d mzab 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 can be seen if a grating with 60xsvx c/ ;cxu/4phk 7p900 lines per cm is illuminated w ucvhc/ x;9s7xp/x 4kpith 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on eitherslw5fxq uk7jo,5c+g 58rb 6ct side of the central maximum when white light t7f5c ,ls cb+5x8r5kguo6wj q is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a graqlcf i.srd1+/i vyx6 5c,pvd:ting withr5v.iv,fyid 1 6 c/l+s:qcxdp $8500\;lines/cm$ 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 wavelength /088zsl2d cm,c wklm s$\lambda\;=\;6.328\times10^{-7 }\;m$ 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 linj6h8asw r,9/fn2vja bes 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,bvtyf *zmpb/,x)s(p e27m2g a what wavelength is most strongly reflected at the cenbv 2s/g7b(am2 p*zxe)f y,mp tter of the outer surface 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 if the glass plat-ytjuh+to7y +6f z ab4es are each 26.5 cm lon y yj6 b-7a4+ufzhtot+g?    cm

  What is the smallest thicknezst ,5xkbpmgb;ta4;,d ( 8svn ss 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 gm.mky 4p ioob6p*vtrv/+x. :($\lambda\;=\;570\;mm$ 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 0 9 syqj(6slj.;kxcz uand 31 dark Newton’s rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a kusz ( 6qx.0;ljcs j9yflat glass surface (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one en -2 ,y2wu8: m;n,t qmg2ru lyo5xjiezgd of two pieces of optically flat glass, as in Fig. 24–33.:xtwg22yy ,l-mu5 ,z2;rj muq8 en iog When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the air/yqj efma p) ni:;wo93,1j7bg)y9z ;sunsh hl layer be between two flat glass surfaces if the glass is to appear bright when 450-nm light is incident l b yq7jhou 931j9,)y/nigfsasm ; z;)wpn e:hnormally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a sdec9kwcjajq-)x7c bpx 1wwk:s e:6x c,0:ay:tolen 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 alcohw2 cv2xakz7j; ol $(n=1.36)$ 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 apparatvv/v2gp g5vex. 2obovms+;uk 5x u6 (aus (Fig. 24–31) is immersed in a liquid, the diameter of the eighth dark ring decreao5gv+x;6xp.2vu2 / v (gv bvoms5uaekses from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength oflk1dq xm dwwc h)od:ji3x4mpc qo5.ik8: 7 86l the light entering an interferometer if 644 bright fringewpd x:8 jccmomq5x )6k7k3hw 4oi:1l.d8di qls are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer.h)9+k,uliq l b ncox k;oca*4: When the micrometer is tightened down on a thin metal fokq) lin4+u:x*olocc, ;a9 kh bil, 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 mirr ngzbt ny.p)7)or $M_1$ in a Michelson interferometer be moved if 850 fringes of 589-nm light are to pass by a reference line?    mm

  One of the beams of an interferometer (Fig. 24–59) passes through a smalld97hz3fxw h bf wq5/q) glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a tot9zw qf35fhb)q 7d wx/hal of 236 dark fringes are counted to move past a reference line. The light used has a wavelength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orie8v,a-e z rmo9c5thmg* nted at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air–glbbsz lt iscpuw;1 .7s4;znv6( ass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamon ga6bj kzt.yhn:g1d57on))9 h q,xlqod submerged in water if the light is hitting the diam tdx7 :)1nhgzo6oh q nk5jqg.9,a)yblond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned s2kq 9y2x q8j.cs4lt nio that the light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequently reduced b2siqqc 8 2ny4.j9xlk ty half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the +h oly .ey2qzeac88 y);0i(uee1qtd rintensity of the incident unpolarized lightae+8;uyqe2r qyli 8ozc)e (e1h0ytd . to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orieza l:h ha./i:fnted 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 orientq2(rp evq5wgov2lo /81 jyjq 4ed 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 anh,yp bhc28e /m1ar +vp*w4tcpgle be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total inter/hc81t vbew,*p 4cyhr+ap2 pmnal reflection, and to Brewster’s angle from above the surface.
If the light is coming from water to air, $\theta_{p}$    $^{\circ}\,$For the refraction at the critical angle from water to air $\theta_c$   $^{\circ}$ If the light is coming from air to water $\theta_p'$   $^{\circ}$

  Unpolarized light passes through five successive Polaroid sheets, eax4r:hpmly- 8o)ki2zaz( zo0 jch of whose axis mz)az2 lo xi-k:(omp yrjzh480akes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength u)1 *mwbrbfsw5f 9b64pq yh1z $ 5.0\times10^{7 }\;m$ passes through two parallel slits and falls on a screen 4.0 m away. Adjacent bright bands of the interference pattern are 2.0 cm apart.
(a) Find the distance between the slits.    mm
(b) The same two slits are next illuminated by light of a different wavelength, and the fifth-order minimum for this light occurs at the same point on the screen as the fourth-order minimum for the previous light. What is the wavelength of the second source of light? $\lambda_2$    $ \times10^{-7 }\;m$

  Television and radio waves reflecting from mountains or airplanes cav1 0w 87zfioiziy-t+mn interfere with the direcy+i1z t0 v8oi wm-f7izt signal 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 grating with/q*xe9doji3hc-q*s s xoijsq sh9 d3*eqc/-*$ 3.00\times10^{5 }\;lines/m.$ The wavelengths of the three lines are $ 6.56\times10^{-7 }\;m$ (hydrogen), $ 6.50\times10^{ -7}\;m$ (neon), and $6.97 \times10^{ -7}\;m$ (argon). Calculate the angles for the first-order diffraction lines of each of these sources. $\theta_{h}$    $^{\circ}\,$ $\theta_{n}$    $^{\circ}\,$ $\theta_{a}$    $^{\circ}\,$

  Light of wavelength 590 nm passes through two narrowjc+jd*y s63xujv/og j8 st e*: 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 th jsj*tyc8 vg*o d/3s+uejx:j 6e 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 fromxkcz9,4 f,rpgy+b1 cdh0f9 jq 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 horizontal c 49hbkfdy +0gjzx1q,pcfr,9ly in both directions. If the midline is taken as 0$^{\circ}\,$, at what other angle(s) $\theta$ is a maximum signal detected? A minimum signal? Assume all measurements are made much farther than 8.0 m from the antenna towers.

  A teacher stands well back from an outside doorway 0.88 m wide, and blows a whisgv19 de1 3mq3;c oi af;cjx/ostle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playgrouoeics/x; fmj d9 ;vo cg13qa31nd outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of woiq7*q 0h-/efn ide) lidth D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of parallel lcl3tc.m- kyokv, -q :fines across them. When normally qto. v3ky-ml cc, k-:fincident 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 must a grating have if there is0re oi fc qkhrs4h:0br iqvh49d(8j:3 to be no second-order sp98rc0 ieo4vh:0:d 43rf iqq(j b hhkrsectrum for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light pmkutk e85* p (besp6,n2tnbisyp j-40roduced by a diffraction grating always overlap. What wavelengths overlap exact6y8np ( 0mbk-p nue, ts iskpbt5e4j*2ly?

  When yellow sodium light9-b bua7rh *j5buum4ufw o+ i:, $\lambda\;=\;$ 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 w tr ,y,jujk w9kas2h12ith and the pattern is viewed on a screen 2.5 m s ,kh9wa j2kr1y2t ,jufrom 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 refraction of a clear material if a minimum of 150 nm94 n8 awhmp1 e(on k1/eklecx5 thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upoe(19 w khpk 5amex 84n/encl1on it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident normally on a thin 6ol+vuv ,5jt ihn-. fksheet of plastic film in ahu n.,6o tl5fivk+v-jir. The reflected light is a minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an anti-reflective coatio;18l6yqbsc xng $(n=1.38)$ 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 (no8nu lqf07j a( hfbsa)g4prs87n-zero) thickness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm light is incident normally? (f h0r)7 bplf8ju4g8a asq7n s   nm
What if the glass is to appear bright?    nm

Suppose you viewed the light tw3l77v4uy 6+irmnyb y; o7m riransmitted 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 size of the minima compared to the maxima+6b vl7riimouw7;myr 74nyy3 and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflec.rp x wwjo3s)vl6e53udr86toting off a smooth lake is polarized most st)serox6p533drw. 6luo 8tj vwrongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to red7cwi1/ a,(yiihlx tyvs22 u:o twg*e ;uce the intensity of the incident unpolarized lighth:so12 i*yixw eg /wcti 72,vyua(;lt by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on t.;agdr k -nlshdc(i51wo polarizer sheets whose transmission axes are at right angles. A third polarizer is placed b1 n sdl (r-g5dcha.ki;etween the first two so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axesgenn--/htdnyoq nb/ +o9 g;-n 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 throughiq:i0dqiynd5(i u+4.zl whp9 a slit of width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon. hiu+ i4 lpidz0(yiqn q.:w5d9    km

  A series of polarizers arexp v.s21y2ru9uaml 0p4im0ri 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 g4ypr/lm )f,5z*pqcft)o, ovayj*u3$(n=1.34)$ 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 raq as b0pj/.ej+dio waves in phase with each other. They are located at poi+0e/bpajqs. jnts $S_1$ 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 t *xff zhx2n-qa9ky7-x wo wavelengths, 420 nm and 650 nm, enters a silicate fli x*a n-zy-h72qfx9fxk nt glass equilateral prism (Fig. 24–58).
(a) What is the angle between the two beams leaving the prism?    $^{\circ}\,$
(b) Repeat part (a) for a diffraction grating with    $^{\circ}\,$

  A Lucite planoconvex lens has one flat surface and one with pp.m/k6qmw03n87yxsymez turq.n* kv,2 vk ,$R\;=\;18.4\,cm$ 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