Does Huygens’ principle apply to sound waves? To water waves? Expl4o l. moirdkz j,pt2y)9 ( az0zr6fts6ain.

What is the evidence that lighta0zs kb56 e-y,.,icvr-sfxzx np6usq9+ y:kk is energy?

Why is light sometimes described as rzjc -da/ fau3i(i 7*mxe)k gd1ays and sometimes as waves?

We can hear sounds around corners, but we cawb8 ic:f h5j j2i7bsx9nnot see around corners; yet both sous :7i52jb8h ibx9wcjf nd and light are waves. Explain the difference.

If Young’s double-slit experiment we5smyun(a 9b4dox8gs ,i.sl5 ure submerged in water, how would the fringe pa .sgsx,(54om uiay 5s9nbd8l uttern be changed?

Monochromatic red light u;w7 xxtl ox5zi;6vb/is incident on a double slit, and the interference pattern is viewed on a screv6xiz;/xxo7l;5 u wtben some 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 destru hwbs a vr384v6q4.pf7:9m sginld1 guctively interfere if their path lengths differ by ahpur8w:dqs9gv 16 iv3bln4f 7m.4 gshow much?

Why was the observationfwvud0b/ d i1; of the double-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffracti;vfd1 d/uwib0 on?

Compare a double-slit experimerb2idudc::wt2f;a 2 h9 f z wsbn5j20knt for sound waves to that for light waves. Discuss the similarities and dinub 0bti d r2k z;wfd5 ha92wsf2:cj2:fferences.

Why doesn’t the light from theu grt;z-: s3exa+q zb.imk++ma2dba0 two headlights of a distant car produce an interference 0qr x.mzd2 b+:ab etu+-zsi3; aa+kgm pattern?

Suppose white light falls on the two slits of Fig.y h4t03tu5o omb,1f nasx f9(k 24–7, but one slit is covered by a red filter (x 493 h y(5 abtfk0uf,oontsm1700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece 5,) 7cwkbupvk of window glass, it is not broken down into colors as it is by a prbu )pw v7,5ckkism. Explain.

For both converging and diverging lenses, discuss how the focal length z*aiez*kbv 2/a4v 7qv*b ud qw18nyv8 for red light differs from thbbwaqe *1 an*4/vkzzv*dyi28u vqv87at for violet light.

A ray of light is refracted through 6s; rss18 a xa:wn 8a-z 5b2t9cstlsglthree different materials (Fig. 24–55). Rank the materials acc gs8 rza8ssa ; s1-btl5:wn9c6alt2xsording to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light solj;*f pi8pmd) urce through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern)lpj8im d f*;p that you see.

What happens to the diffraction pattern of a single slit if the whole appar 6 zn0o. 9huh2hymdek,atus is immersed in,6. md0hkhn o2yeu hz9 (a) water, (b) a vacuum, instead of in air.

For diffraction by a sinv xj jlfl-r++pe4 z u;:+:drbu0z8iuu gle slit, what is the effect of increasing (a) the slit width, and (b) the waj:b4zl du0lx:pfrv- u + ru+8u+j;ezivelength?

What is the difference in the interfeks;fxl/u9 ftq1z:d/mtm/wece / . 1 n4xmtj g)rence 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 advantage of (a) many slixvqz5 ;y*- mkvsy +p5gts, (b) closely spavyzv 5 5-qyp+*k;gxm sced slits?

White light strikes (a) a diffraction gv gkg758do;wx rating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beamxdg7vk5 o;8wg 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 1m j)uo)bj n.*qqszg, nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Doe qq) *)ob ,.zjjgusm1ns your answer depend on the slit spacing?

Why are interference fringes noticeablg5l-qakuk7c 5zovs8g13tpt8v 3pvre: 8m5zde only for a thin film like a soap bubble and not for a thick piev5 753-18 ld8 kcokt85p3ga:rvuztgsem p zqvce of glass, say?

When a compact disk (CD) is held at an angle in white light, the reflfh (h;; w4ycblected light is a full spectrum (Fig. 24–fc;; h(lh4wyb 56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fan5* puuxga2dc v.l1b 5rther from the center?

Some coated lenses appear greenish yellow when/6 ;fbqnx s,dj seen by reflected light. What wavelebq6 ;jnd,/ sfxngths do you suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges,9x2 +zrmvjbb; where its thickness is much less than the wavelengt x+ r2b;bmv9zjhs of visible light. What can you say about the index of refraction of the oil?

What does polarization telbam5 kb/6xcsm /q t8 (8i0oyogl us about the nature of light?

Explain the advantage o)h pe a.ff/vv0f polarized sunglasses over normal tinted sunglasses.

How can you tell if a pair of sung5 c*:wbyzagbj3f* /nl5 oi7qplasses is polarizing or not?

Two polarized sheets rotated at an angle of 9 b-pf+7yl2szv0$^{\circ}\,$ 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 had tf 6 * wka3cfffv93h2wno atmosphere?

If the Earth’s atmosphere were 50 times denser than it is, w 8ekogm86 . ik6hs7q;au:rszoould sunlight still be whi k:mg e7 k6ruso6h.q 88zo;saite, or would it be some other color?

  Monochromatic light falling on two slits 0.016 mm apart produces the fic2g-zy i9cyg4 rc+:om fth-order fringe a c9ig4r -z:2 c+mocyygt 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 v)k(na uuyv 4nfo8uj: exj3+164fbw pobserved 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 uzr s on*f;(i0two very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the centerfu ; (*iorszn0 of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a3fsi s8nr; y-b wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far fsri3s 8 y-;bnapart 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 interferc6dq,khu fy027qyic3 ence pattern in which the fourth-order fringe is 38 6f,0chqq dyuc27i3ykmm 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 thre sv 5ly/ayu*4b5c .hwm1lp m6ough two slits 0.58 mm apart, how far apart are thymupv wcl5y/l 5ae46 1bhm.s* e second-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it i l na0f4rm2z+z gi0i gapfp2)f 7z)6qcs found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible24+ nia2 zl0q )crg76zzm )fapp gffi0 light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass through two opv-vxrqw r,-t( enings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relvqvwx,r t-- r(ative 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 Fig. 24–78k yw9q+v rcw0 so that the two waves enter yk8rqv9cww+ 0the 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 m-qmb gm/z :);mjsd4e;flk .mmitb5v9 aximum for 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 nmk-.vj:qmm;mfid);gts elb m/m5 9b4z 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 p /7u ei)d -yjq,nd8o6;cvebvby 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fringes ond cq7/) v8enyu6;-veo, bpdij a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two slitsh3cb igl pio( i:vd,gyc5)5 .s $6.00 \times10^{-2 }\;mm$ 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 one slit of a double-slit-5m5: kkfjt5k bs h0wb apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximuwt5 s k-b5mk5: khj0fbm, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700 nm) exceed tdqsjb seu3+n4v4j-4 6ezv ml/hat of violet light (400 nm) in silicate flint glass? (See Fig. 24–14.q-44 dsv4m+s znulj j3b/ev 6e)    %

  A light beam strikes a piece of glass at a 602zy :f isp;z:zip7*l7h cc)zty wu52u.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 1nw flutuo0p6 rgdo1,gc89y; 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 fallst/ +piet ldn80y/(gy8se,xyr on a slit 0.0440 mm wide, what is the full angular width of+ 8dnp0x lt r,yyeyte8i/(sg/ the central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls iz3x6g z2in2yv1cgfqnu; s+ (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 im ebo 11ls5j-e(k8clnm 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-q+v3hl ys8c9 wnm light. What is the width of the central maximum (in cm) in the diff3lhcvwy9+8sq raction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm fal)3f*7-1ey p/b6nlra vrw sj rals on a slit. If the angle between thyaf r61- pel )wv n7bsrj3*a/re first bright fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffract n+7hvwihomztmb98 5 3ion peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm lig79mzibo nv 53h+8mwhtht?    cm

  When blue light of wavelength 4408gnh8y.i t5 b/3me; h ziyg830nyyahm nm falls on a single slit, the first dark bands on either side of center ai iy g.n;he3/0ghy8yhn5mayt zb 388mre separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nuzfnyox:; rz 2bjbalr ,75*5qm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55zf2,n lj:7rybabu *;x5z5r oq m away. How wide is the slit?    mm

  If a slit diffracts 650-utp34( 1yhm11 f pytrpaup0e) nm light so that the diffraction maximum is 4.0 cm wide on a screen 1.4(p1t e1 pha3mfpu0u1pt)ryy 50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengtl9b*- do2z wzvh $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a se m5afabsaz:z01y d4dov6f .42 hn9dp ocond-order maximum when falling on a grating whose slits :ya04dmpaad2nh1fo 94 sz .vz6bfo5 dare $1.45 \times10^{-3 }\;cm$ 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-order ( 5.pj/kemiryl, uw2yoccurs at an 18.0uewr 2/j (yylk.p5m ,i$^{\circ}\,$ 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 observe2 qond +*xk9revyi10nd at a 15*vi0e1n9x2+knr oqdy .5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating ha( km0)cocif7q s $ 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 o2 p8dj ldxd6b g./u;0h:gergpn 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 n :im dmb7m94i ;d8vzbspectral order that can be seen if a grating with 6000 lines per cm is illuminated with8imd v9: dbm;ib7m4nz 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spec jir2z w0gz-ij8v.)occns89 atral orders can be seen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximjzgz-n.8w2s8aico0 j9 v)r cium 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 grath-qf ( +,vms 0kv/,eap2xz bheing with h0vkxz 2/pes-,f+ h(, qeambv$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces d:*k to:bnv5 ge*mg-3; e tzz)lkp7aj 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 lines are measi7 9y 2nf8vj3kpxvtw(ured 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 1rn/to ts, 6nrk 6zgn(7mml9v120 nm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normally by white light? Assume tha61sg,on(knvt z 7nr9t /r6mlmt $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass plater*xe;r0l,4u1oa m p dv9;ki6g3. fep *vyexyos are each 26.5 cm lo; 4.rx0 v*vo3 iu9,e6ypmlydef1rxpg;e*ka ong?    cm

  What is the smallest thickness of n7si wz*bhwiz mjxlt6e )c6:;y//f1ua 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 .u-h1jp:acxw;br3cgw6z r1d($\lambda\;=\;570\;mm$ 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 c- mfli3;kv p0bounting the dark spot at the center) are observed when b-mi;l p0f 3vk550-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,ux(q) jxc:w(efsy j512zghlc p-*j r9 as in Fig. 24–33. When light of wavelength 670 nm ic 9wfsxuq *rj5 y1c (e x:(pz-j)gh2ljs 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 layer be b6l+0uh1 z1g+ :ow oshtfupg:getween two flat glass surfaces if the glass is to ag: tufzg6uh +1l 0+ghsoo1 :wpppear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, smy)tn1 bh:esf /ku5 )-droclpnk007 buspected 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 n+j. xrsa9882wly xt f$(n=1.36)$ 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. 24u+h8of5 orf kcb;*ck,o r *aw2–31) is immersed in a liquid, the diameter of the eighth dark riwobk+kf au,c o;5f 28rr*co*hng decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light t(/d0gc+yrxd gv8 gi6a* b 55 )mypgwsentering an interferometer if 644 bright fringes are cx6gg*(dvg) cs i gd+yr8p50 b/5maytwounted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. Wm0 )yaqeo;b i9e2,qs ohen the micromea2;oq0b 9,) yio esmqeter 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 used is 589 nm.    $\mu m$

  How far must the mirrofi jny2z8iw+ .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 through a small gaa pky;c1 +1aklass 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 a+ka 11 kcp;ayline. 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 i1rc,w8 zq1 jdwc9kj :at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anglep0ppom.*itw - 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 hittiniz ymht s)ol9*.p9b ;jg theh9sy9*i t.pb oz)j ;lm diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passinzpsve95r i7g 0g through them is a maximum. At what angle should one of them be placed so that the intensity is subsequentlpseg5r709z v iy reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed souw4/os:2 pm 0l qks-xj as to reduce the intensity of the incidlpk:qx/o-jss u24m0 went unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orix/oufm8d b8ub 9k1k 9m.sjv6hc9vm/ wented 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 roynaux1s ut4 +f:l5(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 n j;nbeuj +o)1surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from ou;+ jnb1)nje 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 pav(2bab :r sx+lsses through five successive Polaroid sheets, each of whose axis makes a 4(b b2+a:rvxs l5$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength h voh7r2t-hv :0bl9+0pp;w o .j u,vjmrhn7xc$ 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 mount)zoro(m6a jln sklqb,pvt 23i38*r:rf/ ysp: ains or airplanes can interfere with theoav yk / ib:2r8mp(oz3 f3*nqtl:r,)j6 lpssr 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 separate6qnf0 0cf 1ngx sources passes through a diffraction grating with 6f ngcn q001fx$ 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 a*0iwtxdnv 8 ;through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A sed va0x8w n*it;cond 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 of the unknown light? $\lambda_2$    nm

A radio station operatix cqy3-psl 1j0ng at 102.1 MHz broadcasts from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both direction plyqx1j-30 css. 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 widr68lk 3nlj8 the, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible83njh l8ktr 6l to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single sjv--u9x+s)t (wyud c ylit 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 parallel l6 gr8 y54tkgmuines across them. When normally incident 460-nm light is reflect 6umy8tgk54gr ed 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 cent+(wk*jq )r6qx a zb diho*h5vi ta/z)4imeter must a grating have if there is to be no second-order spectrum for any visible waveli(/q d+4z*oaa) 5kt hqj*i6)vzhr bxwength?   $ lines/cm$

Show that the second- and third-order spectra of white lk;/xjgogq+v8o tx ;p((l jgb 8ight produced by a diffraction grating alwayo8 ;qxx8o gjlp;g(k bg(/tjv+s overlap. What wavelengths overlap exactly?

  When yellow sodium light, /vw8xynan kh rl5)9 -w$\lambda\;=\;$ 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 odswf.t c(8:g( 5c)wt9f9r* mnq bobtand the pattern is viewed on a screen 2.5 m from the gdbg5 cffcwnso*(: wmt b8t(rtq9.9o) rating. 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 minfmx05g 1l)d5 wxsgl :uimum of 150 nm thickness of it, 5xfld mg s)x051ugwl: 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 answer?

  Monochromatic light of variable wavelength is 1yu b b.70xxq kmvyi6y3w:7 oobi4l5wincident normally on a thin sheet of plastic film in air. Th:i37uxi715 k.xoyo wbbbyyv0 l w 64qme 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 an2v+ nu) 0i.b jjjww6jdti-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) thiclu/u1 dd.ct,cwv 1x o4 du.jd.kness for the air layer between two flat glass surfaces if the glass is to appluwud,dc..1ocx t1v/dd u j4.ear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted thrr+9r ln kz+q)cts1/br ough 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 9cnb /zsrrr+qkl +t)1possible 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 reflecti9czby(5,x:d+zjbkzkh a 61wpng off a smooth lake is po k 5pz+y(jzdaw 6kbz:9cx1hb,larized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce t*4 ml2lwv58u vx myzcv-ocn )o 5o0(eahe intensity of the incident unpolarized light by an additvc*cuom y8-ve0noz2 ov5a4) l(ml x5wional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whoseyz 5lu:qaqu q.;rl*e9 transmission axes are at right angles. A third polarizer is placed between the first two so that its axis .z9*:qe yu5aqlrq ;ul 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 pt.y);fl eveb b x, ud4;mf*km;w gzu-d 5y,*xqlaced in succession with 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 slit of wi8,hqok onzz64 zrd86cc le;1rdth 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Eartz l;ko h66c4zq8d1rreo n ,8czh. 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 are each placed ajl bq, 3jkf-ai-jqj6cp6 3a)z t 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 5hblvvsyb2 r.jkz:abr-zi1,4i7s a;$(n=1.34)$ 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 phase with each oth((3e8e.g*r ut oojzbler. They 3jrlouo(b.(e8*zt eg 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 light containing two wavelengths, 420 nm a xd if*4;6yzdb.t)h i ,naww9dnd 650 nm, enters a silicate9 d aw ,;xn *hf.tid)zwy6i4bd 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 one flat surface +k1kezm7st3 hand 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