Does Huygens’ principledmd3. u4hb8q g k-hw5k apply to sound waves? To water waves? Explain.

What is the evidencey .+u1wkdpqii4+m d(j that light is energy?

Why is light sometimes az :7+qrc*i-qxcf: gddescribed as rays and sometimes as waves?

We can hear sounds around corners, but we cannot see around cornerhk xqsispjq1t713c1: s; yet both sound and ljh1iq k1s1t 3:xp qs7cight are waves. Explain the difference.

If Young’s double-slit experiment were submerged mu ei,aw*bkocr 75,xn yk ix wd6*--q3in water, how would the fringe pattern bek,aqo dkcw mwi x6-ye,3x7-5bu *rn* i changed?

Monochromatic red light is incident on a double sps84j 7ev.2-ttebwi7ba ,t f . iyc7ptlit, and the interference pattern is viewed on a screen som- s.b b827icep,tj4iap7f.t 7 tey wtve 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 long, lr03ip2 the same source destructively interfere if their path lengths nr,l3p 0igl2odiffer by how much?

Why was the observatiofe52 kk*lft a,pgkvy nw**7o;tn1 wh,n of the double-slit interference pattern more convincing evid wety5wkp2n;nt7avf h ofk*,**l, g1kence for the wave theory of light than the observation of diffraction?

Compare a double-slit exper;9kmwrja2;m bf7 x 4nq),g ocbiment for sound waves to that for light waves. Discuss the similarities and bmjrbx4 fgno;k ;2mwqca79,)differences.

Why doesn’t the light from the two headlfhlac wf6ytdi bwh4,4w9mb3 *h 0v9r99yxz q 9ights of a distant car produce an interfz9f4bbx wyfrh* c hlya ,h9d6i m934v9w9 0qtwerence pattern?

Suppose white light falls on the two sli q7iqjysr :+ aoxzuc1 j8c/w:*ts of Fig. 24–7, but one slit is covered by a red filter (700 nm) and the other by a blue filter8+ jiqz/aqrccx1s :u7 jywo:* (450 nm). Describe the pattern on the screen.

When white light passes through a flat piece of window glabw3 u* wz7n-6n;zaybc1o j,g-lpb3ciss, it is not broken down into colors as it is by a prism.cyuc,-z36lb zb n og3jp ;w1i abw-*n7 Explain.

For both converging and diverging lenses, discuss ho1 sgda:ni7s0r w the focal length for red lirndi:70 s 1sagght differs from that for violet light.

A ray of light is refracted through three different material0u8+l0gdqfpj - l;hmn s (Fig. 24–55). Rank the m pdfju +08lln0 qh;-gmaterials according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant s 3wytybjm22sru*- )plight source through a narrow slit between two fingers. (Adjust your fingem 3 wty*2 s)ju-brsp2yrs to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffraction pattern of a single slit if2 0/x.cw:) cx8ocablc)us h0f4la nmb the whole apparatus is immersed in (a) water, (b) a 4/8cl0fx.ba)us:xa h bm0ccnw 2)lcovacuum, instead of in air.

For diffraction by a single slit, what is the efule7y 1 2-w7y 0aoy+ vkpwhv5k jf9q-afect of increasing (a) the slit width, and (b) th-7uak ojea7lp2y1+ wv0k 5yqf yv9-wh e wavelength?

What is the difference in the interference patterns fo 6h4t oqy8b9ko- -mpbuk6e4 bdrmed (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 ./jz,cid )ch6k 5lagqof (a) many slits, (b) closely siqzcg/ jdlh.,a6kc ) 5paced slits?

White light strikes (a) a diffraction grating, and (b) a prism. A 8bge(w0dcb.pbpo 9g(bw 7 6o mrainbow appears on a wall just below thww pbog69.go((b8d bc p 0em7be 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 wavelen7mudosh2z62s uvb 63 cgths between 400 nm and 700 nm, incident normally on a diffraction grating, for what orders (if any) would there be overlap in z6u csdv uhb2632som7 the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeable only for a thin film like a s-t/ h4e8z9vfjxmd h9 w0j0hwroap bubble and not for a thick pxfe-0hw 9hzw0mv jhdjt/84r 9iece of glass, say?

When a compact disk (CD) is held at an angle in white lightw5wv-2gshin /)9s:san 9hm tv, the reflected light is a full spectrum -sv : w5n hs)9gvwht/mn9ais2(Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closerlw*l 2 sv,ehdxdz7e(( together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What wa-a.w5em2b ck7x, s acjvela,5sca-2 x mbk cw7ej.engths do you suppose the coating is designed to transmit completely?

A drop of oil on a pond appears bripd4xzbl: imjh, su/*. ght at its edges, where its thickness is much less than the wavelengths of zlb/x4:s hpum jd,i.*visible light. What can you say about the index of refraction of the oil?

What does polarization tell us abolrf zx-j k/(t2ut the nature of light?

Explain the advantage ppxdj(g6; sp / 8q)/uhoff9sj of polarized sunglasses over normal tinted sunglasses.

How can you tell if a pso 3n m4/ffhd)air of sunglasses is polarizing or not?

Two polarized sheets rotated at an angdilfywti1:on:s19 +qw m 7 l*ple 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 Eq9c zd37 -i,fqc2aw ys8l3s v;*df.5g ze ozfjarth had no atmosphere?

If the Earth’s atmosphere were 50 times denser emiiqs,k 2ww )1iv6 t8than it is, would sunlight still be white, or would it be somse8i 6t, 2)mikwi vq1we other color?

  Monochromatic light falling on two slits 0.016 mm apart produc7qfi3we nas4 *es the fifth-order fringe at a7weqs*ani4f 3 n 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 at an angle of 18*k+z ntxxh u8;$^{\circ}\,$ 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. Successive f4k0il gcxb6uia* en7.c 86eefringes on a screen 8e0e cb k6.4luen6*cx agifi7 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wa cc fevjr,5)bkf q4v9gl, h48ivelength 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 m away9,l rji8g4ffk 4)vch5ecqb v,?    cm

  Light of wavelength 680 nm falls on two slits and produces an interference patt.b kbb: rn*1pzern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separatio znbbp.bk:r1*n of the two slits?    mm

  If 720-nm and 660-nm lid 4w47cpt2twg;fnc3 eght passes through two slits 0.58 mm apart, how far apart are the second-order fringes for these two wavelengths on a screc24;fe4p tcwt7dg 3nw en 1.0 m away?    mm

  In a double-slit experiment,:ok130 6v-ec.crcng)p t fpkj 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 have a 0.k oc) -tfkg6 nepc:p3crj1 vminimum at the same location?    nm

Water waves having parallel crests 2.5 chyd4w;um2jm e)i q1xr0+ x 3xvm 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-throu4v ;m)rixh3ey x qm0 dxu2jw1+gh” direction would there be little or no wave action?

Suppose a thin piece of glimzfj349j+yo ass is placed in front of the lower slit in Fig. 24–7 so t3fo9i+jz4j myhat 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 expe 7ge;pq+lyuqdi;/ ng 4riment, the third-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 will the secondi;qq y+/gd 7e;p4g unl-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illuminated b ev4dsm,cr8 2uy 544 nm light. Find the distance between adjacent bright fringes on a screen 5.0 m from the smc,s 4v8rdu2elits.    mm

  Light of wavelength 480 nm in air falls on two s;ru0i*b.j fzklits $6.00 \times10^{-2 }\;mm$ 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) cover1nf 87df nr51 opfr*ds9 b,vyys one slit of a double-slit apparatus illuminated by 640-nm light. rvodrfyb8* 1,n 7pfn5sf19 dy 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, approximately, does the speed of red light (700 nm) exc ynnpc1m.+hhb(8)ujs eed that of violet light (400 nm) in silicate flint glass? (S.n+)cbys mh(np81h uj ee Fig. 24–14.)    %

  A light beam strikes a piece of glass at a 6ld8tclchkj72- u- w9ux9fce0 0.00$^{\circ}\,$ 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 c.11glqqh9 lg)fj2wv; la 15mqpj ,ykwavelengths, $\lambda_1\;=\;450\;nm$ 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 m:o.y2t0w byonu,oyo8 e* cvw- m wide, what is the full angular width of the centralvo.o* 82 noy cyw:owyb0u-e ,t diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a svkal wioewgy ;y: 85hn j/39wedn9 .h;lit 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)jguq ej -i1cimw8 0n. 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 light. What is thee:cd)dh(q3zf:rz cy2o,iuvw3 akk.,e q5j 2a width of the c2y:,, k.hw3rza equ dkez:cj( 2fiv5d3 aq)coentral maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If t,t0 /.teeg.x 1hxv bzfhe angle between the first bright fringes on eith.,vx .fgx/bh z0eett1 er 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 8o 9lbsc-*lodt:adb7 0.0348-mm-wide slit illumina-dlc lba7o*od:9b ts 8ted by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the fic7s if w1y*f( kma;m)tm p 3x8cotqn-)rst dark bands on either side of center are separated byxf)3-qiy8 ;t saw p(okn*f m)c7mm1t c 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 creat d,2dgo +ryrp)es a central diffraction, org+)2dr pyd peak that is 9.20 cm wide on a screen that is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffraction maximum is 4dhb ;c.8kum*bd 8 p,.kngqf9z.0 cm wide on a screen 1.50 m away, what will be the width of the diffracti;9 d. , mgunqc8bzkh k.f*8pdbon maximum for light of wavelength 420 nm?    cm

For a given waveleng.vg;ptkvmz9 q4ujv*( t /wvmk35 3oiith $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a swemsz0(zte t 22o *b(second-order maximum when falling on a gratz( ezmte0wos* st2(2bing 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 dc0(u**e cm9m 6rhe/9wndyipc oes a grating have if the third-order occurs at an 18p*wu09*e6n/9hym rde(mccci.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 diffractioneai9h.0 nt 3;kmji;ac grating is observedh ji3i9;a a0tn kec;.m 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 hascxt -lafs4 k63j -xd,d $ 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 -g.(c (v maibvon a $9700-line/cm$ grating is revealed to contain three lines in the first-order spectrum at angles of 31.2$^{\circ}\,$, 36.4$^{\circ}\,$, and 47.5$^{\circ}\,$. What wavelengths are these?
$\lambda_{31.2}$    nm
$\lambda_{36.4}$    nm
$\lambda_{47.5}$    nm

  What is the highest spectral order that can be seen if a grating with 6000 6; ndswimul) i d;yg-(lines per cm is illuminated with 633-nm laser light? Assume nor;u;g midy6ds-i( lwn)mal incidence.   

  Two (and only two) full spectral orders can be se0ldzyi a+dty8 u1 2xa6en on either side of the central maximum when white light is sent through a diffraction grating. Wh6lu8tyd ai02 dx+a1yzat is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls ul8 ro3 85/bygdp)xs1 huj -ri.p:,dxyod0wson a grating with5wjdg p-1 lry8) uo0yx/.,o8u bsid3r:x hsdp $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromatic light ofr9h(zlfd7cc l+f6kr ; 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 measurlim j/jjo q9l7m c )5c* o-y1uay95eiwed 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 wavelengtz3 b rn,kfs5j3h is most strongly reflected at the center of the outer surface wh nksbr53j z3f,en 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 gla0r(x: i:qsxaa ss plates are each 26.5 cm long? rxqxaa :i (s0:    cm

  What is the smallest thickness of a soap ar;8 s(gjhjxb.7g;3 yuwe)9d.zjabb 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 k :7 nsfmxs-o yj;5s/lyellow ($\lambda\;=\;570\;mm$ 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’+ls2(dit gl0 ds rings (not counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting ond sd2(+ 0gtlli 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( 0vd*ohge5 k. k/d. bny2bnfs flat glass, as in Fig. 24–33. ysn(d.boh*dk/fe 2 bn .k5g0vWhen 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) shoulzt7 0j/cix +xd+0+/vigh4oenb.rsr bd the air layer be between two flat glass surfaces if tzn47 xi vxg/ bh drt/ 0jr0is.++boec+he glass is to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspetn lhi- h4* ic:li3/oected 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 alcoholxltfdmx(0o *qe*t 78b $(n=1.36)$ 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 (soa/j2pbb-5gu7 iddv98 wp:qvpy 29pFig. 24–31) 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 thevqw/-9 :gu2poj7 v a289spi dpdp5y bb liquid?   

  What is the wavelength of the light entering an interferometer +,o 8t bxx+klnif 644 bright fringes are counted when the mova8kl+bot+,x xn ble mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror of an interferoadw5man3rr jws 9 fq:+9*c)j kmeter. When the micrometer isas5+)9 3drr jkc :fj*m9qwa wn 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 mirri . vaahosyn3:3:6b pior $M_1$ 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 interfu g(9; c2idnxlerometer (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 to move past a reference line. The light used has a wavelengthd;2 x n(c9giul 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 6 bkt-ja l+6ic(*pczq 05$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angleh.x ymupc0 p74yala 8. for an air–glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if tc.zgxyo(lam xka;6 ;0he light is hitting the diamondyxa .gl;0 ko6cza(;xm $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned b2q(v(rl z8to so that the light passing through them is a maximum. At what angle should one of them be placed so 8t( v(rb 2qzlothat the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reducvi,:d/3r,pq3tulv k6 ne y*kge the intensrp kt/d:u ,q*3v,y 3vklegn6 iity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented af-ndxc;fj ve68wj58 -w5g wpcf 6a/ect 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 orientem(d0imax lm5 :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 lmunv c8e4*b9i/ym7 kbe for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle fmimy 9u 7*c8klvb4/enrom 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 pasgwxzai23vl *, ses through five successive Polaroid sheets, each of whose axis makegv 3w*zxli, a2s a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength c/re k ku li/5rnb,*j9$ 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 airp:s axv5bucz441e 3wvs lanes can interfere with the direct:u5 v31zcx44 sbesvwa 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 separate sfu us .cotv8f0o/ hl35ources passes through a diffraction grating with o l5usf3t8.hovu/ 0cf$ 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 thvao :fxh5l/x 0rough two narrow 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 c:fx0ox5a/ v hlentral 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 identick; gcqdn xav2ii8)xdo6g(e ,/al antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the midline (g2v)ixo ke ;dg i8nq6/d x,acis 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 bacm*uec jbt zq7gtgu: +-pce3; 4k 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 *eug;t cu cmbj7 pt:eqz-g+ 34not possible to hear the whistle clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls 0hlx4 g,m,x oton 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 ac xxk:iu .yudl94) miu/ross them. When normally incident 460-nm ligdlu/i)miyuxk. 9x4 :uht is reflected from the wing, the wing appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have ifo58s bwsa/kt2n +6ezf there is to be no second-order spectrum for any vinb2ae z5+tos8/skf6w sible wavelength?   $ lines/cm$

Show that the second- and third-orn zhb0x+tuh7n0q w9.bder spectra of white light produced by a diffraction gth+ub 0q 0b w7.nxhzn9rating always overlap. What wavelengths overlap exactly?

  When yellow sodium lq6s oo:tl7x0l:yna /j7jj7mzight, $\lambda\;=\;$ 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 diffracti/v sy.ni ign;h/tx(6 jon grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consig.; x(/jnit hv6isn/ysts of two wavelengths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ and $\lambda_2\;=\; 6.5\times10^{ -7}\;m$. Calculate the linear distance between the first-order bright fringes of these two wavelengths on the screen.    m

What is the index of refraction of a clear material if a minimum of 150 nm iz:tuykj(v qlwu e1:95 3u1d hthickness of it, when laid on glass, is needed to reduce reflection tu3 vtq w 1 :(91jez:idluyk5uho 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 incidenthry0 w5vc y9f2h 2d9l6 rm9zwn normally on a thin sheet of plastic film in air. The reflected light is a mi50yz drn2h f9wyrl9h6 cmv9w2 nimum 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 coatit)0i zxn/ lk)xng $(n=1.38)$ 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) thic8zwnoqj/nm(6,q7 ld l kness for the air layer between two flat glass surfaces if the glass is to appe7wndn8j(,mo zllq 6/ qar dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted ly8g gmm*9s27 nbd hv6through 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 values of index of refraction. Discuss the relativs2mgn*lghv b78 9yd6m e 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 off a s9nc2) (gdwbo lmooth lake is polarized most strong(9cwld)2bn og ly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to rj05cv0y6h vdun3 wbi :e8md+ weduce the intensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it inmy5ch+ jnu0wb6 :d vdev30i 8w half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls dfgnx7;km .7rl0i) 9 a t glc8wps:f:bon two polarizer sheets whose transmission axes are at right angles. A third polarizer is placed between the first two so that its axis makes)abft7f k mg.;sip:0 8n xrlg79:ldcw a 62$^{\circ}\,$ angle with the axis of the first polarizer.
(a) What fraction of the incident light intensity is transmitted?    $I_0$
(b) What if the third polarizer is in front of the other two?

Four polarizers are placed in succession with their axes ve3 oe,p18f d)g/ti wu5;4rp( sbalt lmirtical, 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 thro ny 9pt56xoh ()cv o3uzv4ku,hugh a slit 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 whhz chk(9v)u43t n, o65ouxvypen it reaches the Moon.    km

  A series of polarizers are each place1lwj0f.:1sh bp t7xg rd 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 dwmm w;+m85y+id,kc f.gj f4e$(n=1.34)$ 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 radiatinh9zr.av7ocetab ;2 z (g 6.0-MHz radio waves in phase with each other. They are located atb.oz;v 2hr(t9a c7e az 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 ligtqa 4ma* h);paht containing two wavelengths, 420 nm and 650 nm, enters a silicathap4m t a;a)q*e 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 ;n h 7pko u+(5dpu3(r,rauuicv2 fm0dhas 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