Does Huygens’ principle apply to sound waves? To water waves?yzx 9/z togv zld,3o33 Explain.

What is the evidence that light is enjq,de 60x2prk4p ahj;o yn4 k1ergy?

Why is light sometimes des9of)rjgo1 sf f vz//)zcribed as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; ynqe3t2,+j wf0mk6xu met both sound and light are waves. Exm+ n xfu 23k6tmq,je0wplain the difference.

If Young’s double-slit experiment were xma5sb+pbv .5submerged in water, how would the fringe pattern be chsba 5+5xbmpv.anged?

Monochromatic red light is incidee wij5a0e zi81jxh (u;nt on a double slit, and the interference pattern is viewed on a screen somej u 1xe(aiiw08hzej; 5 distance away. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if y7kag *t 0nl2/xrbfg+ 6bby3kk ih6p )their path lengths *6kirn y 2/yb )pxtb f376gakbk0+ glhdiffer by how much?

Why was the observation of the double-slit interference pattern more convincg4qa)yz63r yyy-/h 1nusnqr8 ing evidence for the wave theory of light than the observatio r/r3yzn8nhsq)qyy 4a- u1y6 gn of diffraction?

Compare a double-slit experiment for sound waves to that for lightt)*2x(c chnv5d*o3ey:abtjtw(( y m d waves. Discuss v2a(o3cnj (5*ed(tycdwxt* ht y:mb )the similarities and differences.

Why doesn’t the light from the two headlights of a distant car produce 16n((zncu4k lvk0 ynxqpawc:6g s6v29ls5d r an interference patterz(4l sk62ack:wvyu npcdq(n6 x90n g s1 5rlv6n?

Suppose white light falls on the two slits of Fig. 24y-1 xfl*yt fk/–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Des/-yxyf1lk ft* cribe the pattern on the screen.

When white light passes through a flat piece of window glass, it is no3s gq y6mw/dvv2jl *p/t broken down into c 2/p v3gyv/jqsm6 dwl*olors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length ford1aw5v. vb673z kwc nge.a6 bh red light differs fr ..7z wnvd1 awae66 vbcghkb35om that for violet light.

A ray of light is refracted through three d7y5 u (ba3e cll-ugr;alhg+- bifferent materials (Fig. 24–55). Rankl-- y+( gaguaeurl3 bhl57bc; the materials according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a dizp: q1at;s; 7 nnhxhni)c4 u)istant light source through a narrow slit bez: pc7i1h aq )tis;x)u;4 nhnntween two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a sin +w qgvflbk25q ev8+ tjw7(i)zgle slit if the whole apparatus is immerse e+f) 5bqk(i+q 872wvvgjwltzd in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the ex isx+6gu(x+ -.qs5mgt/ kbqwffect of increasing (a) the slit width,ixgtb6x+ (.s/ +sq-5 gmw uqkx and (b) the wavelength?

What is the difference in the inter4yh dwpa:kpn*0 ws0 a1ference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction gra ihh p2.l+wb7 lzs2mgiz(5sg)ting, what is the advantage of (a) many slits, (b) closely (h gssm.+wzg7i hbl 5) zl22pispaced slits?

White light strikes (a) a diffractio2t dnq 3;u:0vyqy ahz dpc/bnt *,aao*so,*;tn grating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow in each case? Explain,p *:a 0qyca 3y*z t*/votdnosah;n;du,qb2t.

For light consisting of wavelengths between 400 nm and 700 nmna,srtat3y u0 w;e 5vi8m;-m g, incident normally on a diffraction grating, for what orders (if any) would -3gita5tsamrn,v 0wu ;e m 8;ythere 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 soapb0bmg sgz8;4bwo3 y2o bubble and not fo02 ms;4ygwbgbb 8zo o3r a thick piece of glass, say?

When a compact disk (CD) is held at an angluu:3rjja78w : lv ya37lxhs0 te in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. Wh8s: tyjwua7u03 av3x l:j 7hrlat would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fartd no*q74 )pvk*44vxvu ccm+siher from the center?

Some coated lenses appear greenish yellow when seen 5+ulyteahg6+ qz 9mh; by reflected light. What wavelengths do you suppose the coating is designed to tranh a t6em9q;yzg h+5+lusmit completely?

A drop of oil on a pond appears bright at its(nj(lb yw;w1pj1 qc f9gs p5m/ edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of ryglcp( f1j51mjs9; /pnbwq (wefraction of the oil?

What does polarization tell us about the nature of le) d8bmbgtu9) ight?

Explain the advantage of polarized sunglasses over normal tinted sunglasses. 15)cr5xi/a(yuu otsn

How can you tell if a pb0m +whgzm y.7pyqn7;8r hu4qair of sunglasses is polarizing or not?

Two polarized sheets rotate:p o-njqxz1(rney4 - sd 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 Eart- l7( .tg* 2wuqfta;knwyp r9ph had no atmosphere?

If the Earth’s atmosphere wevz k48,h gx:fqre 50 times denser than it is, would sunlight still be white, or would it be some other x, 8vhf q4z:gkcolor?

  Monochromatic light falling on two slits 0.016 mm apart produces the fifth-orsld6og 6 n*unf+x5 tn9zef(b(der fringe at antsn o(e9f6zln(6ugbdn5 x* + f 8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is obserc8qd) .qtrqin xga/ -4ved 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. Sucr ;cs(+kd dq .b eob1rw7x9f,gcessive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Dxq1b+rr(bo dd.7;kw ,9 fg escetermine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of lig*wqg 0evu1o s0ht from a He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits u0g voqew01*s0.060 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 slits and produces an in2: g)6lx4is5q( t.tcrnqw jm fterference pattern6t q5r) 4gqswfn:(lj t. xm2ic in which 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 apart,*;c*am43iwvwk t /zkd how far apart are the second-order fringes for thesezw** kci/a d3k;mvt4w two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it if-jaobyx /0o iq44 wv-s found that blue light of wavelength 460 nm gives a second-ordojx fyb40/-iqwo-v4 aer maximum at a certain 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 ptm7) koom1j8dqlk 5) dass through two openings 5.0 cm apart in a board. At 8jdqk) 5ol)m md1okt7a 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 plac+ujbds( pb9 m*m)+n tged in front of the lower slit in Fig. 24–7 so t j)sn9dmp(b*b+umgt+hat 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 li,n,qakd eg7ic i1 1wx7ght of wavelength 500 nm is located 12 mm from the central bright spot qn77k1dg,e,ciaxwi 1on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm ligh/+ qhup8zdiaff** s h4 qo2/qgt. Find the distance between adjacaf duog8 q4pq2hsh/ifz*/ *+ qent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air fis i -(r.;xrbialls 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) covers + i4c:jdm 3detshei1p0k7e5rone slit of a double-slit apparatus4 kde eiim:h5eps1rcdt j70 3+ illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximatelmmj b: ;w(zpti.*qpl) y, does the speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass? (See Fig. 2pm*l: ( m)w.ptizq jb;4–14.)    %

  A light beam strikes a p/tqjv j5k,;0yvhypj7 eo 9n+w iece 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 containua.djb 7mvb c* k6 -.wfx.-s tro9iux6ing 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 an3w nxq+1,sfpj gular width of the central diffraction peak?1fqsxp, n+3jw    $^{\circ}\,$

  Monochromatic light falls on 9kd-oxobyz r9)0 so2d 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 -zdtxx4b8 g7 d cz.c;l520 nm 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 0(8i0 7dvoj 1 i*s;ggfxuyzsblight. What is the width of the central maximum (in cm) in the diffraction pattern on a z10i70jvgs*(oxdsiyg b f8u; screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 w* n;e1 or xg:v3xpu4qnm falls on a slit. If the angle between the first bright fringes on epvwqxg ;4*r:ox 3enu1ither 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 0.0344vch; u0m4nheqq4k2g j c53kx8-mm-wide slit illumixj 4kh c 0eh v2qkm54g4qunc3;nated by 589-nm light?    cm

  When blue light of wavelength 440 d f(,,/bl e 1ik4ecukenm falls on a single slit, the first dark bands on efebe u1ck(il,,dk e /4ither 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 slit, it rz/2yosdtbhwsu p6ucn 33:7c 0 q* w-lcreates a central36nqwb3 d2ts7 :w -ucucplzh*/r0yso diffraction 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 tdnkl+0 0 2e5 :hrdmn0ak*ljlf hat the diffraction maximum is 4.0 cm wide on a5ldh fl 20 kmklrn:+adj0*en0 screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt/5a+i 5mj wvcl..sllkdr/e c-h $\lambda$, 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 falfapc:;s/m9)m j .xbq eling on a grating whosecmb .sq9:p/fm xa je;) 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 thegyt7 v)t9j2t/ ogybf) third-order occurs at an 18.0 9yyf 27tt/vbg))j otg$^{\circ}\,$ 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 fp9wqmgp60;*k q-k va) qym :nnalling on a diffraction grating is observeq mnyp06* m)pkva9w :k-gn qq;d 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 h) r5l-dwr ypy-k.p0feas $ 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 xjxx-)gqk1u(s5s ah1 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 spzc7j1o1tg* 7t(g3jko jugg 8vectral order that can be seen if a grating with 6000 lines per cm is illuminated with 6kgz co*v7gtu3g71jjo ( t81gj 33-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of the k 8ko0 uwr-8/ljp:hec central maximum when white light is sent t8u-k rkoeh08w/lp: j chrough 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 fallsu7.xh ,t1bxy ttwexr;ou 2kd;3 w: ck+ on a grating with . 1docx ut;wtx: k+ery xhw;k,32t7 bu$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic lufd g 13ul)al+ight 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 l33/r k:nr y eux6+kyhby 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 wavels0jp,i6r .coikpu/mj f /a5/nength is most strongly reflected at the center of the outer surface when illuminated normally by white light?/,jkinpaof m/5i.j/sp cru 06 Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass pl2e4n7d yfjdzw. 7w wt0ates are each 26.5 cm longf.d 0 4ztj2y77 ewwdnw?    cm

  What is the smallest thickness ofy .o. 4ro xx1vtni.-wu 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 yello2kb1 hz ;9hvj)pcssv*w ($\lambda\;=\;570\;mm$ 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 (notehk-0 t9spke 1 counting the dark spot at the center) are observed 1ktk e0esp9 -hwhen 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 onei2f c2+ae jba2 end of two pieces of optically flat glass, as in Fig. 24–33b2aeaf j+2 c2i. 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 air3i 3gaoi)h sa/ layer be between two flat glass surfaces if the glass is to oa)3shgaii/ 3appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspey: eeef03aog; rnyvc( v, q16xcted 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 alcohol*u y1wh tb8m-gp4:ylz $(n=1.36)$ 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, 6qg ns cbj2s5mh(j76w) xveq(p ilv,+the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of thq+q75x(v)s lji2 ec6h,g( vmpbwj6sne liquid?   

  What is the wavelength of the(zlffc- 2,0 r hxt(koi light entering an interferometer if 644 bright fringes are , xil0hr((f-otck f 2zcounted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected (qi rz74 mza3uto 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 27am4zu 7(r3iz q2. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirro0 ywayb2d k0ze 2c;ij8r $M_1$ 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 z2xmz2g.*oetii 3t ; oyg-,p;-lz ax iinterferometer (Fig. 24–59) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are counted toyl-2-i3.t i* xgot a,;zizme; ogpx2z 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 oriented at 2 owu :- f*,bai3rwlln65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle f2mv hz51e)p:fo hagz9or an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond subm-;ls9( dl( r9 pxg8szse)s pvnerged in water if the light is hitting the 8(sspd;-pvss )gl rzn9el(9x diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned s0m .77r,pbmg/+ lwjs+mm mu q97srawso 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 by half sb7 r ,srwulg .7wjmmma7m9+m0+ sp/q?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the in/: w7 yzs.xw. 3dofjq3h aq)3uw6plj vtxf) aqv 633 3/7qw swuol.j jhydp:w.zensity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented at 4e bk:t39:d4hhptbunev3,v y 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 o 4vi3l2gzqaz5k (q2fz riented at 38.0$^{\circ}\,$ to one another. Light polarized at a 19.0$^{\circ}\,$ angle to each polarizer passes through both. What percent reduction in intensity takes place?    %

  What would Brewster’s angle be for reflections off the surface of wate,xg1s:;ef tvu l t6 4p4zxr5tk3kps/p r for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle fromf tuk6 zes/5:lppx 3;p4x v1gttr4s,k 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 succesind8phc6 xkt-rpgh 9-- 8knq5sive Polaroid sheets, each of whose axis makes6 5x -8q pickkh-rd89hnp -gnt a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength -5lnjq yg. ik/xi8+ol$ 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 wa4w lax v)7 e2yj0lks3nves reflecting from mountains or airplanes can interfere with )j lek 0wy7vas l3xn24the 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 sh03sj9sc yn (tl5mj,( zkdf1 neparate sources passes through a diffraction grating with 0n mk 53yc1sn(djt9(,lfhs zj$ 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 dw r1kd4a:wb+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 the central maximum than the 590-nm light. What is the wavelength :rdbda+1w w4k of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broad3dc1nw3jf /hi+e dys,casts 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 midf3cj/ i1de,n yd+ shw3point 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 outside doorway 0.88 m wiq76tz8 p k2yytcc(;j zde, and blows a whistle of frequency 750 Hz. Ignoring rzptjz ;8qcy(26 c ty7keflections, estimate at what 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 fal-zo iwchly.h2 -s o73nls on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series of p9tly:45iie i.mgoi )parallel lines across them. When normally incident 460-nm light is reflected from the wing, e 9i4t oiy:pm5i.gl)ithe 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 ioynx74y) iv)mb4lh 8hs to be no second-order spectrum)xyio lbhhn8y 7)v4m4 for any visible wavelength?   $ lines/cm$

Show that the second- and third-order spectra of white light produced by a di,s,cv s ,lj9ajffraction grating always overlap. What wavelengtj,,j ,vs9alschs overlap exactly?

  When yellow sodium light,zbd8aad9q y,ef2 qukg zv*q*h /-j;/ q $\lambda\;=\;$ 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 gratingb:se-c9f ca,o(l3g9 z0*ya dzuv/ kq u with and the pattern is viewed on a screen 2.5 m from the grating. The incidel3u *fzc 9 oqaa :/ ed9yzgk,u(bcv-0snt 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 materiamdv*9p;( naj*;pp(gj 5 knvwpl if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when ligh;a*g vn*p 9k5j wj(ppvpnm; (dt of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength imc2.l xq2cj/ zpo 4)vps incident normally on a thin sheet of plastic film in air. Thqxlcz 4m/.)ppoj22c ve 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 an,/vu0 o kju+3 p s5qd060hpuvekji,m xti-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 (n/x qlh5x2wcr+95f vgnon-zero) thickness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm qn /c+fgx9w5v 2rhx5llight is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the lightml0ghpg5 skd 2 9i3j1g 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 possibl 35di9 gmgp2hkjgs 10le 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 refle b)133dzi ob6g ja7pmzcting off a smooth lake is polarized b )oimzz3 b61adj73p gmost strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce tbo-lwp( -/ x5 hb5l xjbg+x9adhe intensity of the incident unpolarized light blbw g5+x5xl-ho9 x /(babp jd-y 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 two polarize5 tgo(7laf-jgp zj /o;r sheets whose transmission axes are at right angles. A third polarizer is placed between the l5/ foao-j(p gjt;7zg 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 witiow+ap-kybo5y/*, o 3,pxtr kh their axes vertical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a sliu*q+ *5s, d uusmov0fmt of width 1.0 cm and is pointed at the Moon, which is approximately 380um,d50 * uom+ssqv*uf,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers jj97bb/aezz:;gq,g p 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 f v,c4- j9mcciu3cbz5$(n=1.34)$ 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 waves in phaseqe.gbc t8-w8 ag5 9lyn with each other. Thq85lw cn.etbg8 y-9agey are 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 li4m j0av;l6(-i egaq owght containing two wavelengths, 420 nm and 650 nm, enters a silicate flint glass equila 04olva emi -(g6;qwajteral 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 lenq;xw rq9t)frd0i4jn; s 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