Does Huygens’ principle apply to sound waves? To water waves?m3;khpdc8 sx0 -x*qep Explain.

What is the evidence that light is energy mlzdat)b)bi472z.fec a w- l:?

Why is light sometimes described as rays and sometimes as waves?a.941.bq m f; 5pks(k decasmn

We can hear sounds around corners, but we cannot see around cornjg wf:o 3:o jam-wx1)eers; yet both sound and light are wavesj awj1wmf:-:eg3 o)xo. Explain the difference.

If Young’s double-slit experiment were submerged in water, how woux x) lc/em5h3uld the fringe pattern be ch xe)c/l 5hx3muanged?

Monochromatic red light is incident on a double slit, and th;hy;vp /d:zkt e interference pattern is viewed on a screen some distance away. Explain how the frypv;dk : zht;/inge pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same s:0vpph 5r5 6ght hyjcdxq7 .,lource destructively interfere if their path lengths differ hvg tcpph dq:yx6.50 jrl7,h 5by how much?

Why was the observation of the doubay: v0 s0kb(f,4t y2cer g:iufle-slit interference pattern more convincing evidence for the wave theory of light than the observation of diffracv4yu0:, g tfb(20 kay esifc:rtion?

Compare a double-slit experav53k0row o(6iw h.enu9f n t,iment for sound waves to that for light waves. Discuss the similaritiatn,v6 okrn0uei9w .f3w ho(5es and differences.

Why doesn’t the light from the two headlights of a distant car produce an interfvo( e,cru ao)jc;*1olerence oj r*co,l (cv1eu; ao)pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one s6 +ywa1,gih pnkhfc+,a tyr 01lit is covered by a red filter (700 nm) and the otherai+01cfg1 antrw,+ kp yh,yh6 by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flat 4ycrq/.xbgf:p roxg/931j ym piece of window glass, it is not broken down into4grcmpy 9 jf3 /q: 1gxbr.xo/y colors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how the focal lacd 6-tt+p +4fjrv:dbp0nprq6erx9 +ength for red light differs from tha 4++rapt-t cdd 0j:p fb6xqrp9n+ 6vret for violet light.

A ray of light is refracted through three differen1e9 i el6z3c1 fe8tmsat materials (Fig. 24–55). Rank the materials according to their index of refraction, least to greates6m az19eft3cie s 8l1et.

Hold one hand close to your eye and focus on a distant li5 f/:kqv3b 4zgqxsx4rtt5 h(i ght source through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you qxxv : 5g4i(4 tqht5kzrfb/s3see.

What happens to the diffraction pattern of a single slit1vqq/hcww55mig tajgg++6 y 9 if the whole apparatus is immersed in (a) water, (b)+cm 5q 9iat/ y6whgj gw+1gv5q a vacuum, instead of in air.

For diffraction by a single slit, what is the effect of increasing (a) e1j3otkx8qe rs0z 9f 4the slit width, and (b) the wavelength?4s0efr 981qotekjz3 x

What is the difference in the inteq2g0 k hdwv :ints1m::rference 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 sliw14cuuc; l8m wosz/83lwv)oua8w*oe 9 r:vwx ts, (b) closely sw 98 l3cu8a ;o*4wo 1lomx w)/8cewurwvuvs:zpaced slits?

White light strikes (a) a diffraction grat 8:,fyii :6lwa -nrwhuing, and (b) a prism. A rainbow appears on a wall just below tlwanfw-:iyhi,8 u6:rhe 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 and 700 nm, incident normallyp(kj 9nq 5,ivc on a diffraction grating, for what orders (if any) would there be overlap in the observed spectrum? Does your answer depend on the slnkj5iv(q, p 9cit spacing?

Why are interference fringes noticeable only for a thin film like ar4 1 )umjj+-zuy:tjia soap bubble and not for a thick piece of giz j4u )+u1:m- tjjayrlass, say?

When a compact disk (CD) is heldyh +*l eo h.sl2ssa1xesddc mggq p*2,88 3i2n 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 ligd2 8lg *x+lg, sschs2piam s.o*eyn1ed38 q2 hht was used?

Why are Newton’s rings (Fig. fgfq3z 9 r(n obxo/x5)lqb5i024–31) closer together farther from the center?

Some coated lenses appear greenish yellow when seen by reflected light. What n +ly.so2ioc8 wavelengths do you suppose thoi loc2.+s8nye coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness is muc;-p con7vgh;rh less than the wavelengths of visible light. What can you say about the ;v pch-;n7ogrindex of refraction of the oil?

What does polarization tell us about the nature of lig,;8lie9 dsazn.cy/ z pht?

Explain the advantage of polarizedw:mz re:/ud3opbo n*- sunglasses over normal tinted sunglasses.

How can you tell if a pair of sungl 1cp loqsk,vd:gdbe n8 2il): z1*m,fpasses is polarizing or not?

Two polarized sheets rotated at an an /j.7u xi7vb r3qdm2mggle 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 Earthre pi(2f*1 jc3rrs1wx had no atmosphere?

If the Earth’s atmosphere were 5j(mn)+.tgo in y46 bbo0 times denser than it is, would sunlight still be white, or would it be so6y nmngbob .+i4tjo)(me other color?

  Monochromatic light falling on two slits 0.016 mm apart produces thepdc l9/zu:h7 vr87-3wutibh v :8z xma( ert2w fifth-order fring e:ih-r 2h upvxm(r/9l37 zact7v:bdz tu8w8we at 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 at an angle or f;fi31jz2l yf 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 0.048v) k ftbbvio p5(.v)u)-,jmio mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the pattern. Determine the wavelength and frequency of the lf i m.,)vv -)bj)bkiuotp( ov5ight.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656q pdou8qit;( 2 nm, falls on two very narrow slits 0.2i(;t qdo8 qup060 mm apart. How far apart are the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two sar /u3 qwxn6-y pw)08s,vd ptelits and produces an interference pattern in w sw -nea t/wx8p3dv q0ryu),6phich the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m away. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passes through two slits 0.58 mm apart, how f*nf vxv-uub3r1 go8 2rar apart are the second-order fringes for these two waveleuo38-brxn2 1v*ufr gvngths on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nm 7fdyg9j 0d0akur7g 0zgives a second-order maximum at a certain location on the screen. What wavelength of visible light would have a minimum gdauj9 rgkf07070yz dat the same location?    nm

Water waves having parallel ,5i6u1dds/ 9b)ftd/s3enin*xl z ckz 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 the “straight-through” direction would there be little or no wau5ed)*ncfs d kiln 9 / isd/b,x3z61ztve action?

Suppose a thin piece of glass is vtlz dys iv2(/us.:w, placed in front of the lower slit in Fig. 24–7 so that the twodzyw :v(s/il tu s2v,. 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 experiment, the third-order maximump0x cp 4yr6lmn0, 4rfv 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 second-order maximum of this light be loc0x4y 40cv 6p pf,nlrrmated?    mm

  Two narrow slits separated by 1.0 mm are illuminated by 544 nm light. Find the y)aqs . (lqwg6distance between adjacent bright fringes on a screen 5.0 m from the slitq g qwl6)(ys.as.    mm

  Light of wavelength 480 nm in air falls on two slit9 knetw1 e80zbs $6.00 \times10^{-2 }\;mm$ 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) coverm j3 nec1.lfg3s one slit of a double-slit apparatus illuminated by 6l.cg3mj 3fe1n40-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 (700 nm) exce ug;pc z8i m zs.1+*fr:d+pfrzed that of violet +rf*u c+dfzpzpg ;s1r izm.:8light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at 5ruz3p yk:g qdf 7 z,)2xbgqe3a 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 containif r )l7,oh*ka 5w ff4fpf4qnc;ng two wavelengths, $\lambda_1\;=\;450\;nm$ and $\lambda_2\;=\;650\;nm$, enters the silicate flint glass of an equilateral prism as shown in Fig. 24–58. At what angle does each beam leave the prism (give angle with normal to the face)?
$\theta_{d1}$    $^{\circ}\,$ from the normal
$\theta_{d2}$    $^{\circ}\,$ from the normal

  If 580-nm light falls on a sli)l 0as- 7aaiewy*/eih7att ;0 g jvp,tt 0.0440 mm wide, what is the full angular width of the centraa t vy0s,;jga0lt)atepi*aw /-7 i eh7l diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a;:zs/3iwz dkc 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 52kx d40lhj k/e/0 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 illuminated5y e;d5 tz4sof n+xm0d by 450-nm light. What is the width of the central maximum (in cm) insn+ft y50; mo dx4dez5 the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the +44en3tpt wun angle between the first bright fringes on eithewten u+ 4pt43nr side of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffra2 kyfmg;m4 3fxction peak on a screen 2.30 m behind a 0.0348-mm-wide slit ily4 m23f;m fxgkluminated by 589-nm light?    cm

  When blue light of wavelength 440 nm fallsq h eoj0 ,w7lp8kw8h5u on a single slit, the first dark bands on eithhph 8o0k 7,lw quejw85er side of center are separated by 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of wavelength 415 nm falls 1uoi5eoh p7xk m6p/8t on a single slit, it creates a central diffrmi xot58up 1 ohp/7ek6action 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 sz,jh.7t.xdhb; eq iu kb2,j)do that the diffraction maximum is 4.0 cm wide on a screen 1.50 m away, what will be the widku dbhjzhe ;x qt27,.,ib.d j)th of the diffraction maximum for light of wavelength 420 nm?    cm

For a given wavelenggg+rm d5+zvsby69me htkj, *e bh+a57th $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm lzb5k :)qtf3g tight produce a second-order maximum when falling on a : )gtb5qz k3ftgrating 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 have ifmytq9*7u:f ep v4**.k mto uqq the third-order occurs at an 18.9.quq*m ft 7*uykeqmp 4*o:vt0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

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

  The first-order line of 589-nm light falling on a diffraction grating igqh4gz x3:0cr/ac9 hu s observed h r/uc 039gax4:qc gzhat a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingh+mrhd:hv-nf08 ry1 k has $ 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 on2ya5.sn uefwr, f7u8c(.t dr x 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 ca 7f4qiqzi3d6wn be seen if a grating with 6000 lines per cm is illuminated with 633-nm laser lightqdi37w6f q i4z? Assume normal incidence.   

  Two (and only two) full spectral orders can be se.vh;t:/mbms hcv4ew8;/ bokeen on either side of the central maximum when white light is sent through a diffraction grating. What is the maximum number of mt.8;v e/oh/vbbmh:w ks 4 e;clines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengths from 410 nm to 750 nm falls on a ;sw;0dfuttymz9 3cnn9 b vh9. grating with . wd39;t vsfc bzthnm;n990y u$8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromath zu,9cpytb- -ic light of a known wavelength $\lambda\;=\;6.328\times10^{-7 }\;m$ is used to calibrate a reflection grating in a spectroscope. The first-order diffraction line is found at an angle of 21.5$^{\circ}\,$ to the incident beam. How many lines per meter are there on the grating?    $ \times10^{ 5}\;lines/m$

  Two first-order spectrum lines are measured bydlk,0g99ts ,yi9o lssp eo1, k 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 wavelength is most strongly reflected a2xmx: o,n; qd kt4baf6t the center of the outer surface when illuminated normally by white light? Assume,6 fnbqtax:md; ox2k4 that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Example 24–8 i p:u.7h+u kb7ooxj4cwpzs . i*f the glass plates are each 26.5 o*ihb.x 4uz:jpu7kc .op7w+s cm long?    cm

  What is the smallest thickness of a soap uj93lch;b7l 7aorx u7film $(n\;=\;1.42)$ 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 greenishjplb0m;p6gg+ 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 rings (not counting the dark spo e*2j6 d tducm:c;6wrlt at the center) are observed whenj cu6r;tc*2w :6edl dm 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 opticallolfjxj. 4s20ir x(j .ly flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 darkl0(j2 orlij4x .xj s.f lines are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should the 0ievl w 2opcnp16*t *, c+zyfoair layer be between two flat glass surfaces if the glass is to appear bright when 450-nm light iw 2y pnooc v*c,lfe 1i0pt*6z+s incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of beings;7zjpe-vv e b1+w+g y 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 alcoholochy5- n67h os $(n=1.36)$ 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. 24–31) is immersed in a liquid, the diametes5d p pwpccpnc3n 2h zr96r1*s4/xo/kr of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What irnnc/z1occ2p/sx*sd p5kp9w 6ph r 43s the refractive index of the liquid?   

  What is the wavelength of the lighd dgvyu;o5uh0oo7b/-nncjux0)f ( 6z* ix9llt entering an interferometer if 644 bright fringes are counted when txbod07lf9 d5 x/njl* z;vio(0u6gn-hc)uou yhe movable mirror moves 0.225 mm?    nm

  A micrometer is conne47p20/oremuy3 yab zzcted to 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 micrometer, is 272. What is the thickness of the foil? The wavelength of light used is 58y/ruo z30 7p4eby2ma z9 nm.    $\mu m$

  How far must the mirror-m gl (i*22ru7qg,a t gog/3qqtaoa n- $M_1$ 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 small8nm ;i 00kixu*hlfgfw5v9fx , 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. Tfil x00nuf9 igx5*;vfh,8 km whe 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 orienteg.dx-zdtfufs38d( 6 vd 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–glawt asu 6wb-s,4ss $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for vb2 ;4s rbjw) qsl,yv 6 dpmj0gs6ga4)a diamond submerged in water if the light is hittingsd6v ,6wy4br)javs4s g)b ;2ljqm 0g p the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through the ;d)vm8j:hua tm is a maximum. At what angle should one of them be placed so that the intensity is subsu); dv8 amj:thequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed/ 3 jjlwq 35xapmed3h- so as to reduce the intenwl aeh/dj3m-jq x353 psity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented a3rpnqi1/+ w eat 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 orient;wxs flv 1q4a)ed 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/t6a ,dl97q7v( vzi s /-kyhx8czckng for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the surface. 7/d tyncqilz(,/ks7-9zgva cx6 k8vh
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 of whom:o ;gl fq0ipi9 pey7xed/+63 fk z4qlse axis makes a 45o mg9y+ i0zed 3fpf4;ll:6kpq7 e/xqi$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength nmxo5t:q1 ve 5$ 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 mou57ai szr2:jn*zbxu 5 :l0 gjountains or airplanes can interfere with the dsb5::jj lrx ioa 0zg52 u*unz7irect 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 sources passes through a diffraction grating withgi*bc, yagn c8e79z+ky -pk5 w eknpw7* k98zby -+ ci gyga5,c$ 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 thh), nnwe;6 y4xuijr +brough two narrow slits 0.60 mm apart. The screen is 1.70 m rjbnu w4e6 ;,)x+nyhi away. 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 broadcastsvmar.g x0t) l5c n6f6w-lqo:f from two identical antennae at the same elevation but separated by an 8.0-m horizontal distance d, Fig. 24–60. A maximum signal is found along the midline, perpendicular to d at its midpoint and extending horizontally in both directions. If the wx -vmc l): o5 66r0ngtafl.qfmidline 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 wide, and blowcmn6,a.9l vvzw , 5talc x8l:sw d2fk:s a whistle of frequd8ta:v: xwsc w 65vl f .9lm2aln,kc,zency 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 m1aw )kqdr t)k 9t(6eyof width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series oglbs /j35la;c . *n8b ijhoh1mf parallel lines across them. When normally incident 460-nm c 58;bno jbhl*/hmsai31l jg. light 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 *bok 7cv*5oez)e r1ngif there is to be no second-order spectrum for any visible wavelength*ev1 eo)*c5obnrz gk7?   $ lines/cm$

Show that the second- and third-order spectra of wkesuedgbn0 *bzwr y,l-o+*,4hite light produced by a diffraction grating always overlap. What wavelengths overla kl,s4z be*eon+ b0*d-u,gy wrp exactly?

  When yellow sodium lidlgv, /f/) t(ez(vslmght, $\lambda\;=\;$ 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 graj 8v zadfpe 1omx5cj.;4dd0idpp2o3-ting with and the pattern is viewed on a screen 2.5 m from the grating. The incident light 3xef ipd8 vc0;5 mj.pjp4-oaddo21z dbeam 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 of 150 nm tvmm0 ms ay.wh bppxzb 42,c769hickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of 600 nm is incident normally upon it? Do you have a choice for ,zamm9v 026hbycwpp.4bm s 7xan answer?

  Monochromatic light of variable wavelength is inciden31,j br6jmoj5hqf2ie ax: s+ut normally on a thin sheet of plastic film in xom i: f ,53jjsqej+ 62ru1ahbair. 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 th gj9k6r*.9dhf zu7c sbickness needed for 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 d)ovcitp/o1, 6b0ml o /xjl 5mugpb/ *air layer between two flat glass surfaces if the glass is to appear dark when 640-nm ligcv6ud5*0 /ml1 olb,o /mxogiptp)/b jht is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light tran 8isyejx8zrl*/m0:jfi rn 43qsmitted through a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24–30 or 24–36, and describez ij4/erfqn*sir0ly 83x8 :mj the conditions required for maxima and 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 c * .m(+y 7r(ss4qdkavoly* dsthe Sun when light reflecting off a smooth lakem*(vas(qd y4ks7s r.+ody* lc is polarized most strongly?    $^{\circ}\,$

  At what angle should the axes of two Polar-q/wd7 be alf e0c:3vuoids be placed so as to reduce the intensity of the incident unpolarized light by an additional factor (after the first Pola7favdcblqu/w3:e e0-roid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light fa- 3hpg br3)e.i )id1mp/j txlulls on two polarizer sheets whose transmission axes are at rightpe)b u)igmx.i hld-/3rpt31j 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 with their ;v9 7em7(bnhibt;1wmkx fau8 axes vertical, at 30$^{\circ}\,$ to the vertical, at 60$^{\circ}\,$ to the vertical, and at 90° to the vertical.
(a) Calculate what fraction of the incident unpolarized light is transmitted by the four polarizers.
(b) Can the transmitted light be decreased by removing one of the polarizers? If so, which one?
(c) Can the transmitted light intensity be extinguished by removing polarizers? If so, which one(s)?

  A laser beam passes through a slit of width 1.0 cm and is pointed at xr 0+x+ufpzo9 djdq y-t9u/q7 the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red lixx-zq +j7r9o y+ 9t/dupdfqu0ght of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers .bw 0om:1vsw ow19ijf/zg aih /z gb06are each 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 d 2r0 j-xir:sc$(n=1.34)$ 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 radi1)x-m hsvw*at6dp:u;fp-wm i ating 6.0-MHz radio waves in phase with each other. They are located at u;6p *s1:-mvih- dpxatwf w)mpoints $S_1$ 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 l2:fkktw-j* e lo nu,oif78d4cight containing two wavelengths, 420 nm and 650 nm, enters a silicate flintkid*,fo-tn 8u 4jw2:ok7fe cl 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 lesrkva 8(k;zb: ns has 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