Does Huygens’ princip5a4hg2bwul t, *p 9xxvle apply to sound waves? To water waves? Explain.

What is the evidence that light 1-lq ztaqv -h 6l876b teqoam/is energy?

Why is light sometimes described as rg lkb;nx ld-9 1nf-f k-).zsgkays and sometimes as waves?

We can hear sounds around corners, but we cannot see around corners; dj 3x)y+nbz)7fro e ,syet both sound and ligh3f )ndr zo7 je,y)+sbxt are waves. Explain the difference.

If Young’s double-slit experimentma e6q0g p1uc, were submerged in water, how would the fringe pattern 6 e,cgup1qam0 be changed?

Monochromatic red light is incident on a double slit, and the interfeh7e6v6y;k. 2ti mecowrence pattern is viewed on a screen some distance away. w7ke cte;v662 omihy. Explain how the fringe pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same source destructively v6-e5lv h/ i6;uxxjnxinterfere if their path lengths 6xej h/n;-5v6lxvui x differ by how much?

Why was the observation of the doueirmz+b2xt/nq 7:,h4cvumd0n9bw,-uu u5 o gble-slit interference pattern more convincing evidence for the wave t b bq 4: inv/m uwx20en,ot-5rz,guc9uu+d7mhheory of light than the observation of diffraction?

Compare a double-slit experiment for sound waves to that for light i6eem, m,(knu5yo *a -glid8wwaves. Discuss the similarities and w*m8 6ei-go,kmlnd a u(y5i,edifferences.

Why doesn’t the light from the ,ph /w9 sh+toxcsbj8 a8zm:c ,two headlights of a distant car produce an interference pato+, 8c:x m ,ha8ws z/j9hptsbctern?

Suppose white light falls on the two slits of Fig. 24–7, but ost -2ggh5h/s1ic y+xb-c sa n3ne slit is covered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe theyx15-cag/cth bhgs +s3 in-s2 pattern on the screen.

When white light passes thq hi5gt 5rc vd7k--f5erough a flat piece of window glass, it is not broken down into colors as 5hrkc5i-7-dvet q gf5 it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal length for ye971 vxhvarz8eh-j -red light differs from that for violet li 7v1j -zhe-av8yhe xr9ght.

A ray of light is refracted through three b2ll op(91ke i7 2gwaydw8a:jdifferent materials (Fig. 24–55). Rank the materials according to their index of refraction, least to le ajk1 l9 :(yo2a2p7iwgd8bw greatest.

Hold one hand close to your eye and fo* 8rkahl zaw)8j9 obz;cus on a distant light source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you *a 8l r9w)bahojk;z8zsee.

What happens to the diffraction pattern of a single y0ca* ql fwi ,)67hngyslit if the whole apparatus is, ag)wi6q0cl7yh yn*f immersed in (a) water, (b) a vacuum, instead of in air.

For diffraction by a single slit, what is the et h7mtux4g5qihk)sfj0kyv/j+ +uc( :ffect of increasing (a) the slit width, and (b)4tk5t(kchfi 07y+u hgvj: j) /u+q smx the wavelength?

What is the difference in the interference paw:4wytmz* c18w ,hbbntterns 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 c sxwl7z)ko8 n:jsy1h) qn4. sjgxb07 advantage of (a) many slits, (b) closely spaced s1x 7gw.q kon:cy z l0)jx4hsbjs 8s7)nlits?

White light strikes (a) a diffraction grat g0iw;n.. f8la/d*vdrjoqj r0ing, and (b) a prism. A rainbow appears on a wall just below th./g.*jawi ;dn f0rdlrqov 8j0e 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 anx24. gv,e2 ;aviqbgpn d 700 nm, incident normally on a dipeiv4xnvqb ; ag22.g ,ffraction 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 noticeable only for al),r(p,mkimpb96jpx nhnxc sm ruq)585 x68 k thin film like a soap bubble and nox5 h8pm,r8ml pupn6k(q ni k jcb)s)69rmxx,5t for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, the ref**2 pkmz.cc 7umuez 5xlected light is a full spectrum (Fig. 24–56). Explain. What would you expect to see if monochromatic lig mx *257kzz cm.puuec*ht was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the ceno55 g1qjfg g1n9i;l7qck j8c loc9fn2ter?

Some coated lenses appear greenish yellow when seen by reflectebzpcf7 anf9wh6nor tje.+0-/ ye uz)( d light. What wavelengths do you suppose the coating is deu+bz/79tecn frn-e)hzpo 6w a 0.(jfysigned to transmit completely?

A drop of oil on a pond appears bright at its edges, where its 3ujr1,ch1 5gl r0rnrdy/tbz6thickness is much less than the wavelengths of visible light. What can you say about the index of re,hrl/rdycjrbgu65 z10nr 1 3tfraction of the oil?

What does polarization tell us about the nature of ad2t .* 3w0xrek mn9ntlight?

Explain the advantage of polarized su.n rbeem (t2s8nglasses over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizing ord tno,// .vuo4aoam/ ne wlia27(3 ada not?

Two polarized sheets rotated at an angle odx( yi:j3on5; p (g8lq;sujkmf 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;p.,opg5fnoklg 2sd-p39k , mrj/qbl atmosphere?

If the Earth’s atmosphere were 50 times denser ts *p9lk,noj-++uq5 1j qhyl rohan it is, would sunlight still be white, or would it be soh +-1 j+o*5lpkr yqol,9qjn sume other color?

  Monochromatic light falling on two slits 0.016 mm apart prh otwbt7 o, tr*7:5nxloduces the fifth-order fringe at an 8.,7t*o t lxbtw:o7h n5r8$^{\circ}\,$ angle. What is the wavelength of the light used?    $ \times10^{-7 }\;m$

  The third-order fringe of 610 nm light is observed at an a4jok4cfv6 4g nngle of 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light falls on two very narrow slits 0.048 mm a sav2q61- z2gsd su,6mmiwy f;dg;br )part. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the gsu );dmis -; df6,2g2swrqvy b1zm6awavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser2vu 58ibby-j dfc4 bty+uyc4), with a wavelength 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 f)b4 buyyd+v4 tc2iu8-j5bycm away?    cm

  Light of wavelength 680 nm falls on two slits and produces an interference41alel8o.blq1uchf1 b, m/yk pattern in which the fourth-order fringe is 38 mm from the ce uf/la4 bcoqymlk81h1,bl.e1 ntral fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm akm3joxpufl-/+fi055 41n tj. m teqhfy.x 0avpart, how far apart are the sef5o-./4n xu1qt3ph0flm+jyijta 0v x.f5 mekcond-order fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavva8 s5a 8n-lrkelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength ofva -ks8lr5na8 visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cms unin c597ym, 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-through” direction would there be little or , m7i 59usycnnno wave action?

Suppose a thin piece ofsaz 4; s,n+xwo glass is placed in front of the lower slit in Fig. 24–7 so that the two waves enter the slits ;ss4,z waon+x180$^{\circ}\,$ 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 th8-w g 1rys/w5ytq:jav ird-order maximum for light of wavelength 500 nm is w8y r twg vsyj-:/1a5qlocated 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 second-order maximum of this light be located?    mm

  Two narrow slits separated by 1.0 mm are illumocec,ea26l*v9)bnhd kh3ur 2inated by 544 nm light. Find the distance between adjacent bright fringes on a s9nho6vechldab32 u2 * ce, k)rcreen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on two slits6 exd 2zbsv:/m $6.00 \times10^{-2 }\;mm$ 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 pltzsbq )0tn4czrp6-+g astic (n=1.60) covers one slit of a double-slit apparatus illzt4pb cgtns+z-rq60) uminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimum) thickness of the plastic?    nm

  By what percent, approximately, does the speed of red light (700u:nvx5hg/gstm jrz6y1d:cfr/ o440 r nm) exceed that of violet light (400 nm) in silicate flint glasvx0jt:/cg41 dr: fo5/h zs4 ruyn grm6s? (See Fig. 24–14.)    %

  A light beam strikes a piece of glasx fay8pse;l;d n 78if1g8wl3 as 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 wavepx,o8xey t/i fg.wk28 lengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a slit 0.0440 mm wide, what is the full angular wid q)laa ,e.v3w jfq5iuuho.j )a2v/ b*oth of the central diffraction j)elh2* uo,/oaivvbqw53.ua . q j)fapeak?    $^{\circ}\,$

  Monochromatic light falls o1/roqmsdtjn8vrq3,lkz 2 v00 n 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 hq0les49(k/hxtn cjn0 x-mm/n7f6z w 520 nm falls on a slit that is $ 3.20\times10^{ -3}\;mm$ wide. Estimate how far the first brightish diffraction fringe is from the strong central maximum if the screen is 10.0 m away.    m

  A single slit 1.0 mm wide is illuminated 8h0l-w9ng*u bykwt- 5gojwa+ o3uh /u by 450-nm light. What is the width of the central maximum (in cm) in the diffraction pattern on wa-uu/ ggw-l * +08k uhonyh5bj9tow3 a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the ash 8wsv1s,:pv ngle between the first bright fringes on either side of the central maxiv h8spw ,v1ss:mum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen 2.30 m behind a 0.03/8xtwa (b(jkv48-mm-wide slit illw tbk/j((v8 xauminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls on a single slit, the first jl ns w sg ,6o v-7jcw1476jda*gk,x* mjiyo2adark bands on either side of center are separated by 55o*n*cjj7a-wks gw6s 2lvag 6 i,4m,odx1jyj7.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelen 5o(9dv g*8lxmpwl/,p s yjtl:gth 415 nm falls on a single slit, it creates a central diffraction pealyv5:wtglxpdm l*89/ (o,jp sk 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 liml4s9j8u t y;rght so that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the widtrtm uy84l;s 9jh of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelengt: qkc,9dqpjjy *ixh 814 0lu+s1ha aggh $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a second-order (z)er4xxq3fli ul2 bs7l9 w 9gmaximum when falling on a grating whose slll2rz 9f q(u4sw) gb9xx7ie3lits are $1.45 \times10^{-3 }\;cm$ apart?    $^{\circ}\,$

  A $3500-line/cm$ grating produces a third-order fringe at a 28.0$^{\circ}\,$ angle. What wavelength of light is being used?    nm

  How many lines per centimeter does a grating have if the third-order occurs a-s u akh5q:as-t an 18.0sq a -hs:a-uk5$^{\circ}\,$ 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 /dfmc ntnr q5 *xd59g8grating is observed at ax*n/t m5c9nrdd qf8 5g 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction grating has iebi/f. 7mb 9e$ 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 oi,exl/ -b n( 7decwz6 2kaly*;kjpm :on 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 600;d t mpbge. hxj9i6b3odxrr71 g)f7t; 0 lines per cm is illuminated with 633-nm laser light? Assum et3bo ;f.6d7rib7t19 p mjxdggh)x; re normal incidence.   

  Two (and only two) full spectral orders can be seen on eithe /3d :omuny:guc y;3cyr side of the central maximum when wh3c3uyydy o: :/ugcm;nite light is sent through a diffraction grating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a grf m1x:gnm+ic ,8mdqr2z 3m9wbating with c q m:+zb1gmwdfnx i2m39 m,8r$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochkwb;n f0k 4wdrg3z h2.romatic 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 lin5 so:( v: z2nli/exws15h uf8kphw1if es 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,t72m 9a-uhz nh what wavelength is most strongly reflected at the center of the outer surface n29hm zu-ah7 twhen 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 glasss0r5n/bghms9l qjm 8 q :,pvb 57jo,la plates are each apj8 vqso7j9,hlmrbqg:0mn5, 5sl /b26.5 cm long?    cm

  What is the smallest thickness of a soap fy+ e7sqd9m;pi ilm $(n\;=\;1.42)$ 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 greenib+z l-1v 7fj vc6z wqk2yp4dv:sh yellow ($\lambda\;=\;570\;mm$ 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 rinh rp v-)( (qscl0/ qta;i6anuigs (not counting the dark spot at the center) are observed when ; qln hapv6i( rt0a)-suiq/c (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 efv rymyq9r(s/rvp; +7 nd of two pieces of optically flat glass, as in Fig. v 9qy(ryfm/7+rv p;rs24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should thrvetly 3w-7--u q mcj*e air layer be between two flat glass surfaces if the glass is to appear bright when 450-nm light is incident normall73m*el rc- qv -w-uytjy?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected ofoeb wa:vu5a q4)o4h ;nzzy+s * 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 guew (ui93np) $(n=1.36)$ 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. 24hmi.)jy ejobd(,xs o6:n6d( lru:6ci1h h1lf–31) is immersed in a liquid, the diameter of the eighth dark ring decreases:sme bif1hjdon l,ux) (j: di6c.or6 hly 6(h1 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 interferoh2chx ;sw)he1.6tceheb :ri-hzv;c; meter if 644 bright fringes are counted when the movable mir 6;es)rw:hb.ch ;ve1hzxi2c h ;h-ectror moves 0.225 mm?    nm

  A micrometer is connected todf wyrqnd y665/vp2r 7 the movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, compared to the empty micrometer627ydr/5wn6 rfypd vq, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirror 55 86nj fcal2wux-kjm $M_1$ 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 glass a4t )mwj:z7k jzmx-r 0container containing a cavity 1.30 cm deep. When a gas is allowed to slowly fill the container, a total of 236 dark fringes are co4-k :0wmzaz7r)t mxjjunted 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 ori +6y: f)w8kbf(.xzuqot lkd:vented at 65$^{\circ}\,$ to one another. Unpolarized light falls on them. What fraction of the light intensity is transmitted?   

  What is Brewster’s angle for an air– /x;sdfm,6 hvcmq14roa)nn6r glass $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the lighusnb3 *;go tmjn9n0+ut is hitting the d;b n*usj no3m+gu09 tniamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maximgexds- 2bq49eq*yr:j 4i)z jfum. At what angle should one of them be placed sjq):* q exgzjs-b de4r2f9y 4io that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placee0ieq,r u:2sm+ (ecrfr pgnrge1)*b8 d so as to reduce the intensity of the incident unpolariib8 mecn2s1+p g(r*0:eerrf, ) euqr gzed light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orient,fs;i58fwdv0 bmc h.nuss2yuj.+i8i 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 oriented at 3 bf,yx 7fi*z4 e i.:;k3;vpsbbqo v9rz8.0$^{\circ}\,$ 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 surfaceu2q-d uka/( w4i uo9ro of water for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from a4u aw2/ 9u-u( qkrdioobove 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 t6/6vr(2rqtpapc)5 a srpj,ax hrough five successive Polaroid sheets, each of whose ax 6qat ,5 )v/x2pcpprsrajar(6is makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength lsyv,t19,q5c4n xzpz $ 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 bb y6 x+*0jywdv/)fdxinterfere with the direct signal f0ydx) y/w6bv+f*bd j xrom 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 grating with /o/m fr4g af5if/ ar5/ if4mgo$ 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 0hy:45d +r cx6d1svbijocf0w8 .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 5 +0fb divcwh6d:8s1o 4yxrjccentral maximum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 Mqx8;(p h1 2ss l,fw6a3bl h/b(lv udgtHz broadcasts from two identical antennae at the same elevation but separaw /dl; 1h,xsl(6b3avu s t(qbghl f28pted 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 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 w q1j ylq6vt.fp j:4 uumsi5-j:ide, and blows a whistleul:.t u645vm:-jj qiqp1 sfjy 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.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit of width7 l i9*3aipw8chx +gls 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 thubtvr.gs2-kw97. jku em. When normally incident 460-nm light is reflected from the wing, the wing appears bright wh-ks t7buvrj2 .g uk9w.en viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is to be no secrtrrj )k, ;uv0.4l mo .pblr3sond-order spectrum for any visible. r3k04m ;.,vl rs)oblprrtju wavelength?   $ lines/cm$

Show that the second- and third-order spectr:xqfihl- 5ngu w/1- pga of white light produced by a diffraction gratng1u - h/q-:g5i xwfpling always overlap. What wavelengths overlap exactly?

  When yellow sodium lixwvnf8 tl71p7:s 9den ght, $\lambda\;=\;$ 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 gratingzbtd4g 9ku k1oy))sisc3tcw/: 0tqo( with and the pattern is viewed on a screen 2.5 m from t owdb t9 kc1qczt(g 0ytsski 4u3:)/)ohe grating. 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 ij kago.d m 7-fc.0 gvs5ypra(-f a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is inao50.fy as(gg --j .mcrdkp7v cident normally upon it? Do you have a choice for an answer?

  Monochromatic light of vt7 p(yff7c zu5;:oz7o:m3ymk dk e i6zariable wavelength is incident normally on a thin sheet of plastic film in me tzcd 7o:(u;z opk zf:56yifm7y3k7air. The 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 dh5:yo8tv lyg(yu ;hh71+xxn ic/ i3wfor an anti-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) thickness for the air layer between two flat 16vwtyl+)z0( ofi u7 frgh f3lglass surfaces if the glass is to appear dark when 640-nzvi h+y7(l1ufg lfwf )t or063m light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin dg48w )m*56qzx /dsf he(e aeqfilm 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 refractionfs5gdhd*4) e6eeqma w8(zxq/ . 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 z6; ta1mghh )othe Sun when light reflecting off a smooth lake is polarized most strongl)ht1zha;og6m y?    $^{\circ}\,$

  At what angle should tek;g+zezh,.fs66p 0) off cmcb5.k urhe axes of two Polaroids be placed so as to reduce the intensity of the incident unpolarized light by an additional foe5ckp,zug+fbh.6r 6 sf fm e k.0c);zactor (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 a5(jk r sg7w7sk2 vmyg8:vbu 8ut right angles. A third polarizer is placed between the first two so that its a:7ym88s v2 (ubrw vsk5k gug7jxis 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 with their axesivu6 .bk*-t;1 xm ejls 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 width 1.0 cm and is pointed at the-4sn r ;qm2l0uzr6npa3wf 6w w (mu*mm Moon, which is approximate(w2w0sl- mn6pfunm wrm 3u4a mz*qr;6 ly 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.    km

  A series of polarizers are eachflf-a+ :e3o4r:a ro ao placed at a 10$^{\circ}\,$ interval from the previous polarizer. Unpolarized light is incident on this series of polarizers. How many polarizers does the light have to go through before it is $\frac{1}{4}$ of its original intensity?   

  A thin film of soap z:sg g ic3 feq*c+:ss)nh+ bjhty2h+8$(n=1.34)$ 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 eak1adg9bel9m ).i-q o vch other. They are g.ia1dm vq -l9)9kboelocated 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 and 650 7z5:bbrm-kx o6zt d;tr ;eiap/c3p q2nm, enters a silicate flintip;a37kq62t;zo z /br dc-:mx 5eprtb 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 ah fzr49lx o-gr,/ vl1nf*ggc1l:2 t xbnd 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