Does Huygens’ princi x5 ,*xuls.)rf z rq31trcrdu6.7 ssxmple apply to sound waves? To water waves? Explain.

What is the evidence that light is vc epzfd.u)-cmlwh ,th64gwh60e, 5s energy?

Why is light sometimes described as rapevj;r6oro5z+ z(y22 bu cv8wys and sometimes as waves?

We can hear sounds around1apr yl3 y es5a .6v06gx,tnuj corners, but we cannot see around corners; yet both sound and 0a6 6. vgrpe,3a1y tjsx5luynlight are waves. Explain the difference.

If Young’s double-slit experiment were sub ieg3 t24 sv.0o;lcnoka1 yj*dmerged in water, how would the fringe pa* yjs0tvlg1ode. a n234cok i;ttern be changed?

Monochromatic red light is incident on a double slit, and5v n-2)b+qg ,tyjh-pm zi8qve the interference pattern is viewed on a screen some distance away. Explain how the fringtyz, bv-82+np im qvg) ehq-j5e pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively in0h4 )mg :oy5kbp aut;vog. exj5a3 ds2terfere if their path lengths differ by h50ges 25;g b yx mu:h3a.dp avkt4ojo)ow much?

Why was the observation of the double-slit interference pattern v3*ndmxje c ;:more convincing evidence for tedc*x ; :jv3nmhe wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for lightr:f-y)f ki d(,*uhm z a c/ai+a,qy2em waves. Discuss the similarities and differencec)*y/k-fhma(z,qa yf, :ei 2 +damirus.

Why doesn’t the light from the9+p rmh,, z1mwiad4t ,j3zdne two headlights of a distant car produce an interfer z43r1mhz,i + pn dmw9a,tje,dence pattern?

Suppose white light falls on the two slits of Fig. 24–7, buwz::ond.d)hs t one slit is covered by a red filter (700 nm) and the other by a blue fi.n: so) :hddzwlter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glass, it is ne2 m/l9kcv rclydwe u 1l(0:)qot broken dowm l 2d:q/uvwcle(y0k19rl)ecn into colors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the r)g6rwi:42in vuk/zsfocal length for red light differs from thatgr2/)swir : 46kunzvi for violet light.

A ray of light is refracteu bj)vv6;v,mj d through three different materials (Fig. 24–55). Rank the materials accordin )b,v j;ju6vvmg to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light source through a na(ppacel *92ivhi : f1grrow slit between two 1l(a9heg2p*cp : iivf fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if the.- rni6 qu/zx-ae1f de whole apparatus is immersed in (a) f/ 1q-ze xua.6inder- water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (a*t 8 kb-xus6 wyf:i-yuqkld 7*) the slit width, and (b) the wavekyxu*i 8 q-y:7w6*s kbt-lufd length?

What is the difference in thw; mx x7,if,d*fv:pp ve interference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction gratic u* w)6 8kh/de)wflup; r3tming, what is the advantage of (a) many slits, (b) closely spaced se3lhr;6 wipmkuwu f dc/8*t) )lits?

White light strikes (a) *.)ykszn-mnn;a*x 2vjl a1zy/ctl 2ma diffraction grating, and (b) a prism. A rainbow appears on a wall just below than2t2 mjnk*a cmnxl zl.)s-y;1* yzv /e 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 betwee/y4y+:zc mnd0mxlsu -n 400 nm and 700 nm, incident normally on a diffraction gratingm-zmn/ xylcy+4d0:su , for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a s7,f bx sfsmz -e aco:0fq qg6cr5921ovoap bubble and -,mc6x 1cg e fab 9s0oqzvosq5r:7ff2 not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the reflected light2-fh0m l*6(atsg z( *gdyb -2xvb yezn is a fv(bmgze2*-y 0x(- nbf* lzd2t6s ah gyull spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) ccpjl3(p s k1r :zvleooa0p - ll8:j(v8loser together farther from the center?

Some coated lenses appear greenish yellow when feear4ldow7z;0m )5l+8 qbroseen by reflected light. What wavelengths do you suppose the coating is designq4 az8dor)+fl lro570mwb e;e ed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness is mruj xb47gmw4b7,c -umuch less than the wavelengm 7wur-7b x,uj4g4 bmcths of visible light. What can you say about the index of refraction of the oil?

What does polarization tell us aboud:qr0 f:1o rhd7:pza ft the nature of light?

Explain the advantage of polarized sunglasses over normal ti b2l(cbbful yi71o.p)nted sunglasses.

How can you tell if a pair of srt;q/b ge );fuga9v (junglasses is polarizing or not?

Two polarized sheets rotated at/ ljbo/-y7l*pe3mb*d d.bqi. iqfv /i 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 ofrh12 qd x7 qgc3t17yji the sky if the Earth had no atmosphere?

If the Earth’s atmosphere were 5jk0 i6q:o;lu x o.0ixg0 times denser than it is, would sunlight still be white, or would it be someox.;k i 0jui6gq:x0lo other color?

  Monochromatic light falling on two slits 0.016 mm apart pzjv mx(t6; domxtqug(8s(( iz3l ;yh3 roduces the fifth-order fringe at an 8.lqj;zm(z 3s8ixx ht(dtyuv( 6(;go 3m 8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observ8*thzpez zy 5y;y5f :oed 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 apart. Successive4iio xm++ q4oeju,s): :qe mje fringes on a screen 5.00 m away are 6.5oq i:je )+4ioq+4:xumemjse, cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light y+gmsmg yx*5-q0v/) anp6 rxtfrom a He-Ne laser, with a wavelength 656 nm, falls on two very nar* s v) 0 n/mqyxg56pxryatm+-grow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two 2acsj8ur87b o slits and produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. s 7a8ojb urc82What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, how far a) gup k4m+x;gjpart are the second-order fringes for these two wavelengths on a screen 1.0 gm)up x +kgj4;m away?    mm

  In a double-slit experiment, it is found that blue light of wavel, 5tn 1lctm 7uzso 7oz1oll7+cength 460 nm gives a second-order maximum at a cerz lsol1on cot5l+c77,tz7mu 1 tain location on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two openingd .b k -;2:c+npdv j.zug7mh.a dfpwhpme4+6ss 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “straighthzv.; ed4fm.j s.pbpk:h +c+mwpdgu d2na 6-7-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 Fig. 7ndji9ch z wv;0m8a (lo3st8p 24–7 so that tw;0hsv 3i(o 8dznj7 ml89pac the two waves enter 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 maximum for light of wavelength 5. :t ameppl5lfy 1n wmnf4,9p/00 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wave5mp w.lnlpt9 n,y:1ffm ap4/ elength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illumi;kvcf46mwrv6w;2u6pxn f:8 z yzadb 9nated by 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the slits. ncb:w 62r8wu p; ;zkff9 46v 6xamydvz   mm

  Light of wavelength 48z+qk kn3g(i; a:ihgx)xy35 hs0 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) cove anwjj2j 7ba/h7waa :cy(cgk1+24q ta rs one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a tqac2h4:(a j 7wyjnbaagc 17ja+/w 2 kmaximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximath rvb*d3ds57h/w x2o xely, does the speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flintx /vd5dr 3hbwsox h72* glass? (See Fig. 24–14.)    %

  A light beam strikes aqi zy /wbdzs4y 1tbe3 po2z6++ piece of glass at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light c:x h+deewoka tv)j1x8z 1m2m;ontaining 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 theejb056,v mkd f full angular width of the central diffractidebk0 vfj ,5m6on peak?    $^{\circ}\,$

  Monochromatic light y5n27x6yp 5 zzyoc;z34i put)e3bnodfalls on a slit that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength 520 nm fall2zdme ,5z.r tb6 nehf(s 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 lig mk7vkxu;(2seht. What is the width of the central maximum (in cm) in the diffractioukk2 m(vs;e 7xn pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falljpw5f/n g)9f o e/ /wixtbih44s on a slit. If the angle between the first bright fringes on either si n9e/4 wifgioh5x4f j)/t/pwbde of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on0 5eu mgnx lbf5i5+f8ty kj..c a screen 2.30 m behind a 0.0348-mm-wide slit illu. f5kn 5cemi5jgf +0lbtxy8. uminated by 589-nm light?    cm

  When blue light of wavelength 440 nm fallsjpqj6e kr5z5 i;8aj p33ul:wk on a single slit, the first dark bands on either side of center are separ ek6j;p r3j kqw5pa3luj8: iz5ated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls on a singgvoj*: al *2uale slit, it creates a central dif ajgvu*2:o l*afraction 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 diffraction 95t9xl,h*dke ck fde(maximum is 4.0 cm wide o 99(k5fcl ,*kde thdxen a screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt34a hfz3a kgebi( j5/ch $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produ ,hs2qu1 z7mq*my8iwmce a second-order maximum when falling on ahq7qy12mz, m u*m8ws i grating 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-order2-rw m,xv*eu r occurs at an 1w -r2*rmvu xe,8.0$^{\circ}\,$ 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 diffraction grating is wc s3,y)hs6ek 1t 3zqtobserved at a 15.1)h 6s s,zq3k3c wetyt5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratinmu,1ycb4vzz+ 5 n- t19zgftax9o f7 uvg 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 normalgw(o o/r a5s.fly 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 orde n-o )wipnv d0+rqou*e 0anr.-r that can be seen if a grating with 6000 lines per cm is illuminated with 633-nm las0 aov+iq- ) w enun.n0r*rd-oper light? Assume normal incidence.   

  Two (and only two) full spectral orders c .flt ,3;4d+spkgk/uqhp h3 ohan be seen on either side of the central maxitk33 dh+plopk/ ;fu.sqg h h4,mum when white light 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 grating 5fd +u3ppvgd;with5dg p pf3dv+u; $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which producesn a k prl-a9f :wx+ddp202k3hj monochromatic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum rk-s7n,2z uv3c .ywql 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 th4(;zqqi)in l -z5heoaick, what wavelength is most strongly reflected at the ;zqiq)(ona i5 eh4z-lcenter 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 fring.c r d61u4oqt.; owoh8 hxiv7ges in Example 24–8 if the glass plates are each 26.5 cm long? 4hoovx r t. .6c8w71hdg;iuoq   cm

  What is the smallest k8:.1b 1g icd z:jpra3oiw5uo 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 greenishnbzl.ehk0 s5co+ hn0, yellow ($\lambda\;=\;570\;mm$ 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 (e g;,io *vr7 jkq,v;gc :eg)rfnot counting the dark spot at the center) are obsr gq e;ov*g,7;j)kc:er v,igferved when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces of optically flat glass, ak9llo 2ho2 7v wg-dvkfjo+) c/s in Fig. 24–33. When light of wavelength 670 nm is inciclhwj+-)g22vk olv9o7d/fkodent normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) shou*sb*bc) x 9ljold the air layer be between two flat glass surfaces if the glass is to appear bright when 450-nm light is incident normally?bs* lbx*co9 )j    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stlu :6tj bl6nhup h1x0z/, e*byolen 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 alcoho8qua 5 tti)z2q m9kt)3egyjtn26,kf i.jotv 8l $(n=1.36)$ 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 liqukwysl jpxv3i11c6 1p.id, the diameter of the eighth dark ring decreases y3 kplj1.sv1cx61piw from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light enteri4 hj;j 6j h:egpf,)jm/ h8d5i6bm6szpg9bgb rng an interferometer if 644 bright fringes are czh);mbg:br/8h6bfijd5694em6 j g h ,p gpjjsounted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connec:q*hb v/hxj3 eted to the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer, is 272. What is the thickness of the foil? The wavelength of light vh/x3: j *ebhqused is 589 nm.    $\mu m$

  How far must the mirror u msp*k ,jl6d /bkt30p$M_1$ 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 ths6z6 3c - slvskf4be- 8kr) ymtx/yp+frough 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 wavelsesvk)lfz b4+3c/y- s xy68tfk m-pr6ength of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oi(mx da.6ke7y1 hpod,pjwu31 riented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anwt(6jtrv mo. 4t(zna45 f) wndgle for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in walbl -x3h0. d9trjid6rter if the light is hitting the diamon-hrl0.6td93jd lr xibd $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing throu) 3lzijdeib0hyapjk5 m ;*/2lgh them is a maximum. At what angle should one of them be placed so that the intensit5eai khjl 23mp;j0*dyl bi) /zy is subsequently reduced by half?    $^{\circ}\,$

  At what angle should pn dznl:ww4r4k /z;5k the axes of two Polaroids be placed so as to reduce the intens4zlnwk:k r5 n ;pdw4/zity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at 40 afmcv64;e0sronyhdkk qiq 034 m)sf8 jvh13 8$^{\circ}\,$ 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 37)v;a4 ne8kilrvgzt ctx8o+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 anglczv)vsi ct 89l0f a3m5 ;aw;uke be for reflections off the surface of water for light coming from beneathwiacvk s)lu;zft ;mv8ca 3059 the surface? Compare to the angle for total internal 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, each of u ;ku9w-1tj00:4z yzp0k j 4jc wydcxiwhose axis makes a 45jpjx w4tw 1:yu;c0kk-4 djz 0cz0uiy9$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 2 6w;rklghef0 8wn8 gd$ 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 . ic(of0o)jvpdd 7 kej3a1 n4vairplanes can interfere pi.f )c3vnd vk0e 41d(ajoo7j with the direct 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 separatebc6vsg h5es 06 sources passes through a diffraction grating with c e6s5 60bgvhs$ 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 narrow slits 0.60 mm apart9h a(fjd 9n0ai. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm light. What is 9hj (f9a in0adthe wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broad qhy,ng*r,* xycasts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline ,*, gnyr*qhy xis 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 out*zmzck 8nqi7; side doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what* q7i;zmck8zn angle(s) it is not possible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a p/ 1xu tl( fxw29y.koqsingle slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain bb+7msj;t8 l h h;jpa+keetle have a series of parallel lines across them. When normally incid7thlsm+b ;h; +jj8kpaent 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 cenvv2vw+ n wk,37kodf2vtimeter must a grating have if there is to be no second-order spectrum for any visiblewvvkno fvv 2,7dw+2 3k wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light81lj;w o1vjc z8(+p0u fd;n(hrxc lxt produced by a diffraction jhlt 8zo8cx lv j0w(;p rn1 (du1xcf;+grating always overlap. What wavelengths overlap exactly?

  When yellow sodium l8by sht m().+/ vnxbylight, $\lambda\;=\;$ 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 hm rf)8 ;+ajob7ltk .gdiffraction grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam c7k fhjbamg).o8+ ;l rtonsists 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 159)9 yd r cxsxl x*nhi(ylbi3360 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normallynrx )99x cl(h i63y *i3dybxls upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelen j;jz)s6h1edxygr0i 4gth is incident normally on a thin sheet of plastic film in air. The reflected light is a minim0jes)z; 164ijrgd xhyum 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 an4. n nzw5zx +wtjoqx7*ti-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:w qhdjby/ ( ,*f6cvgg air layer between two flat glass surfaces if the glass is to appear dad,jq :gh/*yb c fgw6(vrk 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 thi 4g fyd1/mnyw(n film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the condition14/fmn( y gywds required for maxima and minima. Consider all possible values of index of refraction. Discuss the relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is the Sun when light reflecting od-h7 be bzwnsv ,nt y7v;1(+yoff a smooth lake is polarized mostb(; h7tv sv1z+7enon -w bd,yy strongly?    $^{\circ}\,$

  At what angle should the axes of l4,w .cj eam6d; ihudq4j w9p*two Polaroids be placed so as to reduce the intensity of the euijj 6ha 4 pw;w,l.c d*qdm94incident unpolarized light 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 two0--0b lybw jv:wg q ulfp-*.wq polarizer sheets whose transmission axes are at right angles. A third polarizer is pll.w-qb- 0 wy-vf*wpblg0j:q uaced between the first two so that its axis makes a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axes vertica89mf o i*z.8clyhs f2nl, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 1.0 cm and is pointk9(o .9 -lcs1elz, ydc sud)oned 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 then-y ks9o(dc.z9e,cou1)d l sl beam when it reaches the Moon.    km

  A series of polarizers areu+u dqxf1ui.u;kp 4bwj5 x :o4 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 g2lqi 26etq h3$(n=1.34)$ 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(w v-tip0io*2, twliw -vy/pe radio waves in phase with each other. They are0(oywewp*v /2lt, t v-ii- piw 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 lighy uqup,t+- hcs 7of+k/u(*xtht containing two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateralk(,/ +uo hfphq*y7-+ttuu xs c 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 -; qzc-2ma(i-sujvzf/n g j n/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