Does Huygens’ principle apply to sound waves? To water waves? Explainb8o9gdy 0bb8v1gzhq9 0 aa80okzeln5.

What is the evidence that light is ener 6pwg8cl o7c5xo*caj3,)zh2e fpe .cd gy?

Why is light sometimes described as rays and sometimes as wavd/ h ukx 8f0gtgb45c:bes?

We can hear sounds around corners, but we cannot see aroun s5dp) st6eb5dd corners; yet both sound a e56)d5 pbtsdsnd light are waves. Explain the difference.

If Young’s double-slit experiment were 0gl;g0j g+ oansubmerged in water, how would the fringe pattern be changedl0 0gna+jogg; ?

Monochromatic red ligh,tscm,gfcp (s5(9yww+e,sj k t is incident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the re w,(mctyj5+fgswk( e ss, pc,9d light source is replaced by a blue light source.

Two rays of light from the samecw.gtuw 4 t9 gk*c+6+e*xunes source destructively interfere if their path lengths differ by 9ugtncww 6g+tsx.u+* e *k4cehow much?

Why was the observation of the double-slit inj,xkt5()60h 5eba5daorb;f j cusn1z terference pattern more convincing evidence for xoe 6 rjbaj(nzc d5,h5s 5b1)t0fua;kthe wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for ljn k2x2wk21bar )wagk+688s ogz)x eeight waves. Discuss the similarities k)1s6ja2kea2ww) gox 8x+8b k2ngr ze and differences.

Why doesn’t the light from the two headlights of p0wbn7*on +wwv*ad xe*hgs 6, a distant car produce an interference pattero *nsnh ewwp6a+*vw dg *,7xb0n?

Suppose white light falls on the two slits of Fig. 24–7, but one sno0mmqsu: r47sfx*f1 lit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Descr 0 x1q fsmnfm4o7*sur:ibe the pattern on the screen.

When white light passes through azfkk3u4o, -qd flat piece of window glass, it is not broken down into colors qkk d -of,43zuas it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length for red9dxk7(hz/j/ i4s xx ha light differs from that for violet light /xas kh74z9(d /jhxix.

A ray of light is refracted thrgd7-vm2m+ea3p(lu s ypsy(a7 ough three different materials (Fig. 24–55). Rank the materials according toyamp+ s-m3u 7 yd7velag2( p(s their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a :cniqtmj 5v6. q5bso w3d/wa ;distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe55q bjmo;q6/3v:wtwnsi acd. the pattern that you see.

What happens to the diffraction pattern of a single sl3gyfs 6ldscf-i2 62h ,ic-xej it if the whole apparatus is immersed in (a) water, (b) a vacuum, instead 22xy 3-d,ihjsc6c-l6 fgefs iof in air.

For diffraction by a single slit, what is the effr-tbx (u2wts4dxnciq o q0m, (pe( k;/kveq76ect of increasing (a) the slit width, and (b) the wavei/07 m b6uq(dkcqrexwe,s(2k tn vp 4xt(qo;-length?

What is the difference gxwzncy jri,.p27r,thx ul x4-)(i6rin the 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 advantage ofoa70q9*2czr pi zkbetu +v(3u (a) many slits, (b) closely spaced sli*2z bu+ea7 ut o3c0riqp v(zk9ts?

White light strikes (a) a diffraction grating, andp - bccps;;b-b ;ssb.r gz)v0x (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is thb;s - xg pp-;)v cz;cb0bb.srse color of the top of the rainbow in each case? Explain.

For light consisting of wavelengths between 40vazb*.n0 )x9-cuf vhe 0 nm and 700 nm, incident normally on a f)ae0*-xuncvb.h z 9vdiffraction grating, 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 noticeablel7w; i(bo7 rxc only for a thin film like a soap bubble acxr7;(lowib 7nd not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white lightu qeu/sp )sz0 z8/6of 32gv+dtzu 3qvu, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromaticud govzt zu6 p2q)evzq u83f+/s3/0su light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the centek:ws qe5 io.o)r?

Some coated lenses appear greenish yellow when;qlih7 s3su h0j85b em seen by reflected light. What waveleng3ih7 bs;l0je 85mh uqsths do you suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, wher,knf9b/kar exf 41 5ol-+h - otrkano.e its thickness is much less than the wavelengths of visible light. What can you say about the ind/nk+or9 b nkra 1,kt-.a-h4 5foexlofex of refraction of the oil?

What does polarization tell us about the nature of light?xhy h8wqc. *5568 wzbysopg8 xy)ckw3

Explain the advantage of polarized sunglasses over normal tinted sungla2mr+k3-ha: *o nzgs upsses.

How can you tell if a pair of sun fdd8mp9evw. ,glasses is polarizing or not?

Two polarized sheets rotated at an angle of*m,akdpj:zhr *z*38ei8isjo 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 )o nnqt 08x8i tzc1d*8kts,ygEarth had no atmosphere?

If the Earth’s atmosphere were 50 timh0+uc7qb+ahol7fgc 0 g xkr/3es denser than it is, would sunlight still bk qgohbh/c07 30cx 7rf lu+ga+e white, or would it be some other color?

  Monochromatic light falling on two slits yq4hcy u 9w;nctr9:u.0.016 mm apart produces the fifth-order fringe at an 4.ucy:t9;w yrc9q n hu8.8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 61f, -byba)q(n ggky (t/0 nm 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 nardq6k 84a2bez b)gn m.trow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determin6d8bm. eqbag nz4) 2tke the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a waved ropm-o.,av k+ xr1) e)(6lrpvm4beflength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6(+.v)lo1a -r) bvefx4pdrp,km r6emo m away?    cm

  Light of wavelength 680 nm fa/k.bi r)c 6hszicw-,ylls on two 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. What is the separationsc . c-by,k z6w/hri)i of the two slits?    mm

  If 720-nm and 660-nm l n ):gi6ler;+i*au omqight passes through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screen 1.0 m awayg ie*o+m a:)l6;r nqui?    mm

  In a double-slit experiment, l9xfhg-a8: xpit is found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the sc -lhgf 9xa:p8xreen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having para,c c )edmm:7io:go 7r-t6ezcyllel 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 dm rz ccmg7e7eooy)-::tc,i6the “straight-through” direction would there be little or no wave action?

Suppose a thin piece of glass is pl p3n4gzhn+r7 yk01d izaced in front of the lower slit in Fig. 24–7 so that the two waves enterh yznk731rp0gd +zni4 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 wavele yw uknp+d9).pgxi xw63b (jh,ngth 500 nm is located 12 mm from the centra pw hpwu6bdy)3 .(n,+jxx g9kil bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm ligq8jr sb h7j4*eht. Find the distance j eh* sbj47q8rbetween adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two slits1 2).j8ihpwb p;crqc fu ars:*5ay9av $6.00 \times10^{-2 }\;mm$ 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=1.60sajxr2n/1,rqb 3 /lj n) covers one slit of a double-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plasts 1/ na3bjlqjxrn2/,ric?    nm

  By what percent, approximately, does r4v -+e;hhqlb 5do0bm -fn .ks4z)s sxthe speed of red light (700 nm) exceed that of violet light (400 nm) in silicate flint glass rq l0+m h4 d4sb- )ssv5ne-hoz.bkf;x? (See Fig. 24–14.)    %

  A light beam strikes a p/o9 umi q3o,kkiece 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 containing two wavelengagkcz/g/c+9 y,w au, pths, $\lambda_1\;=\;450\;nm$ 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.j+b3 x , z;qs5u+g8m7sz iqamy0440 mm wide, what is the full angular width of the central diffi mqsza8zqyj+ g5;b,7 sux+m 3raction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit that w ii4kgo pxa y9(/--c2y p8qxx+f0 *b9rtdunvis $ 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 slit that is-c7-aw *v x-hlalhow0le6k2d /h- krr $ 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 5 gj9u(hih; -x.lubjx450-nm light. What is the width of the central mu5hlu g-x.xj i j;(9hbaximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of vebv:h rek u,0a6 ,e/zwavelength 653 nm falls on a slit. If the angle between the first bright fringhv0a,k ez6ere:vu ,/bes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak o:v)mp0ha/ rfuk6,omiptn ;.-k6zjk tn a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 58kr .n- ) hkv0otiuj,;a /6f6p tm:zmkp9-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the fiy;d -6idl,c zlrst dark bands on either side of center are sepl- 6dz; c,diylarated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 n3t2js5wwq aje umg dsw064w 6-m falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide tjw23j0q5wd es-uaw6m6sgw4 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 maximum v8 (dolr5x zbs /6d(srd,.ond is 4.0 cm wide on a screen 1.50 m away, what will be the width of thezorsrdb.n o,d58/s dv(lx6 d ( diffraction maximum for light of wavelength 420 nm?    cm

For a given waveleng/nb5hgg w xcqgs9yj/(; ab(;nth $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm ay4ln;b l.:pm light produce a second-order maximum when falling on a grating whose slits ; ba4y.l :mlnpare $1.45 \times10^{-3 }\;cm$ 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 hav-fb*/ eeowec6t .3rwijp s68ie if the third-order occurs at antjbfe6o8* 3isww6p .re /c ie- 18.0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

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

  The first-order line of 589-nm light falling on a diffrpqlxu,xy(:bda 81h 1aaction grating is observed at ah,a(1 blyx8q a:xp1ud 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating hdcd-(gv9.0lf rm o6 enas $ 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 a towebs+hhe0ox0 ( 82j $9700-line/cm$ 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 thahdwj+9 3qex4yt can be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser ligdwxq 9e4jh3y+ ht? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on either side of the centbif70nx;1m.l3f gmqeu yd +8 n8jczi8ral maximum when white light is sent through a diffraction grating. What is the z7 8lm1 g nm y8iexn;j f0bic3d.q+u8fmaximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on alq;-gqg t4hl54 daq+ i grating with 4ha q gt-4;qqi5 lgld+$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic lig.z v8 txf3xs/y:d (wkbht 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 areg7le9b5 2x5-qlb+x xiqlq) te 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, what wan u oy/2um7b3nvelength is most strongly reflected at the center of the outer surface when 3boy/uunmn 72illuminated 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 the0 /e* tu 0; s xyiqx*x0(v6bdxixyqb2g glass plates are each 26.5s*tqx0(;*iv xxix quey6 bx0dg0 yb/ 2 cm long?    cm

  What is the smallest thickness ofhqa1o- z097cmht l g2d 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 8umr e dj+-jgac) p37tyellow ($\lambda\;=\;570\;mm$ 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 (55w;*tkav zg 5m;be2 .cndkvjnot counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flawz5 gv k5.ek; a;tvjnc5b2dm*t 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, ce4 (lf;9ej1t9ux7;bys; -w mlyeg0qr kiwc,as in Fig. 24–33. When l-c1wyxf re e7tlg9usyl q,c; e4b;;m (i9j 0wkight 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 kq hs 5blh (,78ffl9wnlayer be between two flat glass surfaces if the glass is lbnf79kf8qh5h( s w,l to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a s krpj )ektxrg*9g/pb61q+f 7,d(t gxmtolen 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 alcoholcj2v6jod * cmmc i+ 43kk qc54esi,t* imun7r3 $(n=1.36)$ 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 *iu3) c jm y;vw7qc:rs(Fig. 24–31) is immersed in a liquid, the diameter of the eighth ;wr3j7cvs:miu)yq *c dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interfer(usbmy o+gpk- v./9nzometer if 644 bright fringpkgo. v-nmz( u+ s/y9bes are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferometer. qp.su(j /hf/zWhen 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 thicknq. /s/fp(ju hzess of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror jd u5me23fng7bd**( hl *mjq s$M_1$ 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. 24–5w)d.. y7yc adx9) passes through a small glass container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the containerc.xy . d7w)dya, a total 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 orient3oi 0 sp(rhvbp)5 va7led at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s a6gok:slrj+umf4 mi. +ngle 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 hi); qim(yywt-utting the dyuwm)(- i;qyt iamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are alros*.*n 0k.gc czmtf-igned so that the light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subse-s* * mnt.gc.rcofz0kquently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Pol+qd, x*r/zyfwtf; 9ffaroids be placed so as to reduce the intensity of the incident unpoxwf,ft q /*9f z;dfr+ylarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriear1 ;r9ls tvw awn0m+98.i9g z(kbetented 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 oriente9o,mcjz 9kvt: d 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 water fortsd)p 79tvsn0 light coming from beneath the surface? C7vt dp0 n)9tssompare 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 Polaros(x2eg q tt)dp56kew( id sheets, each of whose qk2pdx6s ((ettg w)5eaxis makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength 6v c i iyhi5j0bvj7(fbj 00arvsz82b-$ 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 reflectdrv1 -+xzzn3ging from mountains or airplanes can interfere with t nxzvgr+-1 dz3he 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 sepa/3lh vxrvom8 7rate sources passes through a diffraction grating with /o8hvmv 3r7x l$ 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 0.6uq.fh 7b u(3x,o ufrz00 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 ,uz.f3 0obuqfr7(xh u 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at ng.h.e bx( 9vi102.1 MHz broadcasts from two identical antennae at the same elevation but separated by an 8.0-m horizontgv nxi.(.bh9e al 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 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 r; qfejf2/i p.an outside doorway 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on the playground outside tj/ ;e.if fp2rqhe doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of wi.d;x vwsfg- b:8oa2xfdth D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have :,ln,f p8kfq7qcgh+ ra series of parallel lines across them. When normally incident 460-nm light is reflected from the wing, the wing appears bright when viewed at an a,8fqcrf k7+qh: pl,gnngle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have)xqdwh 2 9in3b if there is to be no second-order spectrum for any visible wavelength)i nxb9whd 32q?   $ lines/cm$

Show that the second- and) j p40s*4ormnm orh*f8q9xqm third-order spectra of white light produced by a diffraction8m**)mop rqro4q49 j0 h nfxsm grating always overlap. What wavelengths overlap exactly?

  When yellow sodium lightc5 mi7x3 o1)qjevi t7g, $\lambda\;=\;$ falls on a diffraction grating, its first-order peak on a screen 60.0 cm away falls 3.32 cm from the central peak. Another source produces a line 3.71 cm from the central peak. What is the wavelength of the new source? How many $lines/cm$ are on the grating?
   nm
  $ lines/cm$

  Light is incident on a diffraction grating with and the pattern is vie.mx::nus +gompvyi (5 wed on a screen 2.5 m from the grating. The incident lighm(u5nos v:gp: xym +.it 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 ltuap k*-7lj *of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero w**pul a t-lj7khen light of 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of v3bnfep2 s )qe3ariable wavelength is incident normally on a thin sheet of plastic film in air. The reflected light is a minimnee 3)fs 3b2qpum 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 coatine i )a7d xdz,y7p3cj9wg $(n=1.38)$ applied to a glass lens in order to eliminate
(a) blue (450 nm),    nm
(b) red (700 nm) reflections for light at normal incidence.    nm

  What is the minimum (non-zero) thickness for the air layer between two flat j+wv39vepoivct o//*glass surfaces if the glass is to appear dark when 640-nm light is incident norm/cvw 3e*/vi tojo+ p9vally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layered + 3m0fwznk1 wlon a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima anzlwn k01 3wf+md 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 yriag oxu;wm 6+6;(p*pigav1off a smooth lake is polar* ipg ;g; a1aw6rxym(pvi+6o uized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce th4yu /iyc+uds 7e intensity of the incident unpolarized light by an 4yd+7us/i cyuadditional 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 whose transmission axes are ai 8xseu2pn4.d t rigpexud2is4 .8n ht angles. A third polarizer is placed 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 wit7q)kg 2bueuz9 h 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 mg1e5//c io/v; xy.xl/ig:l x/vaq xuslit 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. ux gg qlcie5 l/y :ixovx;avm1 //.//x   km

  A series of polarizers are each placpsd) ed:z67 v1o ;wnzmed 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 k*x1uz ko 6x9o$(n=1.34)$ 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 ra0k; svlw97+86cy0 5ov jgg w/jm dq0bxmql0xjdiating 6.0-MHz radio waves in phase with each other. They are located at pom7x+c8gwm ; l06wy0v jjg9sokq/ xbldj 00qv5ints $S_1$ 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 wavelelt v9lcy e8 1 spexa30,7jsfv+r3 +dlwngths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism (Fig. 24aftw+l y,v7 x 8ve1sls3j+93 lce0drp –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 oyi-d. v:gc uh9ne 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