Does Huygens’ principle apply to sound waves? To water waves? lk8q-fx4 v; s qrib8cnw81qc+ Explain.

What is the evidence that l ck ryi 7gf29 -mq+mx0fsn43uaight is energy?

Why is light sometimes described as r),c2js/rtgy 2azm 3yz ays and sometimes as waves?

We can hear sounds around corners, but we cannot see art;ncnm kea+bk 1;;+hp ound corners; yet both sound and lig+ 1+tmb;an;pkhk ;encht are waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how wob..h hx2o6 zwduld the fringe pattern be chanhz o6 b.hwx2.dged?

Monochromatic red light is pds2j6 k0azu 5incident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the fringe pattern woua5dj2k6pzs0 uld change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively interfere if their path len.do a0p(x yjoj9 a2/zfgths/.(o9yza p0xf aj j2do differ by how much?

Why was the observation of the double-slit interference patterna/ygoa 3o1 bo-3u*pfmtuxxz 47y 1h;m more convincing evidence for the wave theory of light thx1m*f 3ayy-pt31o4g; h/xoubz7a u m oan the observation of diffraction?

Compare a double-slit expvaev2yym wnx/ 3d2:2 c4u)mn qeriment for sound waves to that for light waves. Discuss the similarities c3wvd2my a)4:v2nx2e/ nuqmyand differences.

Why doesn’t the light from the two headlights of a distant car prpe8+4 dfmc)i goduce an interferencc4 i8d+mg )pfee pattern?

Suppose white light falls on the two -;au lczw a43ju*jxw w vyz4;vu8-c(5 oq-hm gslits of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the scr;5u -zjcwqlu4;um*hjw(z8v-avo cwg xa3y- 4 een.

When white light passes through a flat piece of window glass, it is not brohi p)d, /ynxo3ken down into colors as it is by a prism. Explain/ ho3y,)d pinx.

For both converging and diverging lenses, discuss how the fo1zb4 *owik ;h 5xir-zqcal length for red light differsi; 5z41hqzo rwxb*ik- from that for violet light.

A ray of light is refracted through three differ5f /q7ksexuciz18j)mb i0f*so)a)c a ent materials (Fig. 24–55). Rank the materials acco)zek q8u7 scbxaf0 i5i fa)ocs*m1j)/rding to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a5r q6): b6cehhl ydkp0 distant light source through a narrow slit between two fingers. (Adjust0e6cbprq l :y6kh)d5h 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 whole apparatus :j-os2 b qu,gqsv2 o 1(s8hg3x wkcw5qis immersed in (a)x q:8j vg,-b2g52(usqhs wsw oqoc3k1 water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of inch;r7jvqplq6z / .o 8lgreasing (a) the slit width ;/ph q6llzq j8.og7vr, and (b) the wavelength?

What is the difference r z,d .k:s0 wvsg4wsfs4)wgx/in 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 of (a) many slits, (b) clolnw-9z(jymx81v se 4a sely spaced sna s9-xey8wj1z( v l4mlits?

White light strikes (a) a diffraction grating, and p.rfvi;t2w7 a 0a,-l qm vg74oxfrmx*(b) a prism. A rainbow appears on a w,mm.ogw* xfv f402-arxai 7trp 7;lvq all 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.

For light consisting of wavelengths between 400 nm a38 kvwh-6cd kend 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on 8-eh36kvw dckthe slit spacing?

Why are interference fringes noticeable only ffrqp sk0c4u; g;cl3r:gm 9dh, or a thin film like a soap bubble and no rdc sufm4 0lgch ;k,:r3;pgq9t for a thick piece of glass, say?

When a compact disk (CD) is 4 ck 5(k3aymebheld at an angle in white light, the reflected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic bk4m3e ca5(yklight was used?

Why are Newton’s rings (Fig. 24–31) closer togethd ; i;gnbrzj96l;c9sjuuqjs:d20r 5 yer farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What wa /lnccqmj-l.fac744v velengths do you suppose the coating is designed to transmit fj/cqvnal-l.cm4 7c4 completely?

A drop of oil on a pond appears bright at iyi1f h,)5mo5eu p,l du6j)ctwts edges, where its thickness is much less than the wavelengths of visible light. Whatwif5 uu ),cpjdy6 lt)m, 15eho can you say about the index of refraction of the oil?

What does polarization tell us about the nature /jy ( p*u7waxuof light?

Explain the advantage of polarized sunglasses+mja h:;f--v+uejayo ko3z2b over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizing or nr f2ft9)1eixky+w; lw ot?

Two polarized sheets rotat993i*hz :htp 8c5appg9 gy4b/achzm fed 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 Earth had no ;j sen fq5llv 8ad2w2)atmosphere?

If the Earth’s atmosphere were 50 times denser than ik3 oj(y ew;t*(n,fskp vf7ru*t is, would sunlight still be white, or would it be somuywfk*p ( n r*f,k;7oj3e(s vte other color?

  Monochromatic light falling on t 4f6hf .15kgkai)w*8srk .d - bkrxclxwo slits 0.016 mm apart produces the fifth-order fringe sw1ik bfx.krx kah )f6l8 -r *4kdcg.5at 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 observed atl swzld8p0f*oc 0m7*ceny-j * 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 0x* cirppf p+ s/8h7sunarrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart /0pspuf+ip 87rhcsx* near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of ligf e l-i(tm(t:r4 nmtjqc:u:wt1ji8s 1 ht from a He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far apart arecitltw -ime un:8qmr: :st ft((411 jj 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 prod3ybtn/* x8t6+goeyhg uces 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 sepxh+y3yt g6/t o 8b*ngearation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, hoqfyek*;v3tbsm3j n k,(dwvg: ( g ic,/w far apart are the second-order fr ,s(w k/ gy( ficvj;e*tm3dgn:bkv,q3inges for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experimenti*ko-q5win4i/ m( kgk, it is found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light would havg o5q/ii(- 4* kkmwikne a minimum at the same location?    nm

Water waves having parallel crest4ff 38 kpo-ires 2.5 cm apart pass through two openings 5.0 cm apart in a board. At a point 2.0 m beyond the board, at what angle relative to the “straight-throug8k e4fo3 rifp-h” direction would there be little or no wave action?

Suppose a thin piece of glass is placed in fron0mq;cl2v 3f tligyolq., 3 lm2t of the lower slit in Fig. 24–7 so that the two waves enter the slits 18flqo;y3m2 0q2tlm llc 3.g,vi0$^{\circ}\,$ 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 thxo vv7/3ndl2tird-order maximum 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 nm is then projected through the same slits. How far from the central bright spot oxlvtv2/d7 n 3will the second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 m(;7 yye vxatgn;uu/ ou+xt:s .m are illuminated by 544 nm light. Find the distance between adjacyv(/toxuu ;uygen a .:st;7x+ent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two slit,)y a*2 xoug 5(nvqke:vsz u4ss $6.00 \times10^{-2 }\;mm$ 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 (a-ej:k nobbh:q7jfuz,b icjt7 3;( nplastic (n=1.60) 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.o3ei7q -u:jnt hf bn7cj;baz, :b((kj What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, doer :jr(. ayxj2x 49c0krllu5qcs the speed of red light (700 nm) exceed that of violet 9j:q r (rcc5ykular04j2xx .llight (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes yss4 j emawwvqpu; 2v;1k;u;p 5qu 0s1a 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 containing two wavelengths, w36/pszdo7 msp 3vl2n $\lambda_1\;=\;450\;nm$ 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 o is/ t9s-h)zgy:gl3z wide, what is the full angular width of the central diffractiong/)zy l3sh9: io stgz- peak?    $^{\circ}\,$

  Monochromatic light falls on a slitas p im k.r9-rc :l cy-m5i9.tv4p(acy that is $ 2.60\times10^{ -3}\;mm$ wide. If the angle between the first dark fringes on either side of the central maximum is 35.0$^{\circ}\,$ (dark fringe to dark fringe), what is the wavelength of the light used?    nm

  Light of wavelength 520 nm falls on a sli0vluc,nfhx -o5 wq q:4t 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 illuminatedmx -tl(2en/ob by 450-nm light. What is the width of the central maximum (in cm) in the diffra- 2xe bol(/nmtction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wau dih1l8w2rowtt2 * 1wvelength 653 nm falls on a slit. If the angle between the first bt82 wihorl2wwd1t1 u *right fringes on either side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffractintpg8d1 m8y*gon peak on a screen 2.30 m behind a 0.0348-mm-wide slit illuminated by 589-nm light1 8gng8tdpy m*?    cm

  When blue light of wavelength 440 nm falls on a single syhy2inmocs*g;3pt kp 5 9nq5 )lit, the first dark bands on either side ofc; )*ohnkt2 mgyis5 5y3qpn p9 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 singl+y:pq fefrf( o;d/c- ce slit, it creates a central diffraction peak that is 9.20 cm wide on a screen that is 2.55 erdqy(c/ co+;:fff - pm away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum is 4 su-b y :.vlu7b/bjlt4.0 cm wide on a screen 1.50 m away, what will be the widt. -b vjslb:uluty 7/b4h of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelength gmw87; fa1o-;uuez os$\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a s rua lxp2t-k *8zvh1d6econd-order maximum when falling on a grahl- t z6d82 1*rkvaxputing 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 h7mqok/ h 3yw8gen w2cam/6.s:w fs3lhave if the third-order occurs at an s .68c fnwwahqs2k//ly:w 37 emgo3h m18.0$^{\circ}\,$ 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 fallief0ndpkb5* ( yq( (mopd/eez+ng on a diffraction grating is observed5e* mkdpepq0o/ +( def(nz( yb 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 f a7;b:(gp wpsp c9c*nhas $ 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 i23qy+8q fsnv v6di.ja $9700-line/cm$ 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 th7i07zx hdoii:at can be seen if a grating with 6000 lines per cm is illuminated with 633- ixzo70dhi7i: nm laser light? Assume normal incidence.   

  Two (and only two) full spectral orders can be seen on 9sbbtoz5*1s*r (e ycuwfno44 2 f 7ynaolj4g9either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of lines per cm for the gratilo51(7sns9yoc4e rtjnu9 g44y2ff ba* w o*bzng?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a grv);ss : 230/mfzj3kjtpph gnwating withsp)t: 0;/mfw gk 233jpvzhsj n $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromati-y6(tlxh05zol9grj u c 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 l+pl*hzt c.+u rines are measured by a $9500-line/cm$ spectroscope at angles, on each side of center, of +26$^{\circ}\,$ 38$^\prime$,+41$^{\circ}\,$ 08$^\prime$ and -26$^{\circ}\,$48$^\prime$,-41$^{\circ}\,$ 19$^\prime$. What are the wavelengths?
$\lambda_{26.72^{\circ}}\;=\;$    nm
$\lambda_{41.23^{\circ}}\;=\;$    nm

  If a soap bubble is 120 nm thick, what waveleq5kgw pcr :-hy1 , an3jf pqtyix47;(ength is most strongly reflected at the centn3:x(1qhk7;4 w-etpgyyfc 5r qpa ji,er of the outer surface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 if the glass plate(ru j177r qm0a k24 tr-jk 63rvebcyyws are each 26.5 cm lkatrm-rq03 4rky wjj6r b 7(7uey 2v1cong?    cm

  What is the smallest thickness of a soap fd,9dk zem 9f ,0k6re4 h5hduj.qx :cvfilm $(n\;=\;1.42)$ 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 yeh7)g+nwc*ell llow ($\lambda\;=\;570\;mm$ 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 counting 11a7pdtcsskwvm o( ls+4( -i1fp6fv dthe dark spot at the center) are observe klwisdasdf 6417m1op(p1 vs( cf+t-v d 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 fl.)q-s0opa53w 8e -e bli*k8iris lyluat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thice i0oi.slysb k-e-lupwi*8 l85) q3ark is the foil?    $\mu m$

  How thick (minimum) should 5 wusw(ud.:oithe air layer be between two flat glass surfaces if the glass is to appear bright when 450-u ud5 .i(osww:nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen diamond rdk-z7d7+mlh..cu5z)y fvhe )b2mx2 jg g;wl$(n=2.42)$ 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 alcoh+ zibgx ),tkz .km;s0kol $(n=1.36)$ 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–zq*c9m7 s rer331) is immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractive index of the liqm 7 q*rrcsz93euid?   

  What is the wavelenguk78texsk+ up(.k0 j lth of the light entering an interferometer if 644 bright fringe.+ tkl(eku70ux sj8pk s are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable milfk;z *,wvc r9rror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared;f* c,l9vzr wk 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 mir0huga 4b9r glx 79arcd6 r5h4rror $M_1$ 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 int1up9 tsj(k(zaerferometer (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 (1kp zj(atu9 sto 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 orientedckfjll(6*b 8+z8mj k -bkcvw :q4/eh i at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s anwfnagch,z6 w/h-gac2.i9s 4 sgle 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 04b*at3 jv,gmyywh,w hitting tw,yjym ag ,ht43b*w0 vhe diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are alignez 5 bjwta1yhb067t ni05mo 1dqd so that the light passing through them is a maximum. At what angle should one of them be placed so that the intensity is subsequ 6m1z tqt7550bn0hijow bd 1ayently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be pzv1 15cmrmzgn /pc9 f)laced so as to reduce the intensity of the inp) nmzcfz/vmrc 9 g151cident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orient94nyv/oo scpm 0xee y1h;/zc0 ed 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 orien+l* gc 6cito2yted 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 relr6h5hm urb0imjow *kqp/)2w9 a 5*nbflections off the surface of water for light coming from beneath the surface? Compare to the angle fowaw05o9nb/l 6rm*5b) h mjiuqhr*2pkr 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 ikj5*z6kkc x tjm;m30;,cmeiof whose axis makes a 45x06em 3citc5jzm* ;jk,ki k;m $^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength v850mn bl7gh6i w hk0l$ 5.0\times10^{7 }\;m$ passes through two parallel slits and falls on a screen 4.0 m away. Adjacent bright bands of the interference pattern are 2.0 cm apart.
(a) Find the distance between the slits.    mm
(b) The same two slits are next illuminated by light of a different wavelength, and the fifth-order minimum for this light occurs at the same point on the screen as the fourth-order minimum for the previous light. What is the wavelength of the second source of light? $\lambda_2$    $ \times10^{-7 }\;m$

  Television and radio waves reflecting from mountains or airplanes can )1v ilh-5unevf9pt (linterfere with the direct signal ( lhelnivf -tu1)p9v5from the station.
(a) What kind of interference will occur when 75-MHz television signals arrive at a receiver directly from a distant station, and are reflected from a nearby airplane 118 m directly above the receiver? Assume $\frac{1}{2}\;\lambda$ change in phase of the signal upon reflection.  ----待选择----constructivedestructive 
(b) What kind of interference will occur if the plane is 22 m closer to the receiver?  ----待选择----constructivedestructive 

  Red light from three separate sources passes through a diffraction gkfajr2c,f2 i u0wvo6 )rating with k20,iraf c)j26fuw vo $ 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 pass0* vb6eylcl: jes through two narrow slits 0.60 mm apart. The screen is 1.70 m awaycj:v60l elby*. 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 of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two ident82xh)r wf1k6qm jevk 5ical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A kkm)12je6r8 v 5fwq hxmaximum 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 bacs boa jst)d4dj 0 u:gzwt*b 5-v(w*s2pk from 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 the doorway.-v4t ) sjwotp :jg5a2 b0dwsd**(szbu    $^{\circ}\,$ either side of the normal.

If parallel light fanj7ux7cx8 8gz lls 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 parallel lines across them. Wo)r5dq2y bwhywux6 +,hen normally incident 460-nm light is reflected from the wiwqb) d,ryo +5h6y xw2ung, the wing appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if therery r4i g b-yudv 6tab m**s)n:j;p:)te is to be no second-order spectrum for any visible wav r**)4gt-r bajy :6:;deyupnbmtivs )elength?   $ lines/cm$

Show that the second- and third-order spectra of white light prown1o2-k1k py hwhm;5sduced by a diffraction grating always overlap. What wavelengtoys hn;21h m5-k1k wpwhs overlap exactly?

  When yellow sodium light, 9uqdg)smys83:xoo2 y $\lambda\;=\;$ 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 vief3-r10qqv raz wed on a screen 2.5 m from the grating. The incident lightzv0f-3qr q 1ra 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 clearj 96-jg((ki1c x9erf4aqr ps;gttluv8s i09n material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 prx1t(69u9cssiin l f9g vrg;j 4-(0ke 8aqjtnm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of variable wavelength is incident normalq7l 9tbcm:5b tly on a thin sheet of plastic film in air. Tht9m7lb b5qt: ce reflected light is a minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an anti-reflective coating-9lvr o0pz;z q $(n=1.38)$ 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 thehqudlbmzw8ybt *+ 5-; air layer between two flat glass surfaces if the glass is to appear dark when 640-nm liguq dz 5bbl;hy w*-mt+8ht is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmi;c /x+ oqt*fgltted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describe the conditions required for maxima and minima. Consider all possible va/lco x+ qtfg*;lues 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 wheap ha8s q,8k8mn light reflecting off a smooth lake is polarizp8qhmaa k,s 88ed most strongly?    $^{\circ}\,$

  At what angle should the - +6akzk/vambaxes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an addi b6ak-/ mk+zvational 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 transmiss seosbwj;,,a+ ion axes are at right angles. A third polari ,wsj o,b+;saezer 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 plac kg;+xi zcwg9oqx /0d93zq1w oed 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 -4x 2c*a.iyqquyh +s,f k: p(mc1 nzzwa slit of width 1.0 cm and is pointed at the Moon, which is approximately 380,000 km from the Earth. Assume the la.cyc :*,izufs12m(qx p+nw h ayz-4kqser 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 a3 y4ejq*5+*ojrh z yoju* (tfkt 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 +2qb tomqlv7sqzh2 0) $(n=1.34)$ 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 radiom;r z95 se9uma waves in phase with each other. They arem; 9 ur5eaz9ms 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 ligh nn8tlzj66zxoe,s(1x )h+ vi lt containing two wavelengths, 420 nm and 650 nm, enters a silicatesl+eh ljxtiz v8n6 nxo(6z1), 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 su rfropv+f .zb:a;l rilg274j 0rface 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