Does Huygens’ principle apply to sound waves? To wate:c bp,.bcoya2d;+ mkq1o chw2r waves? Explain.

What is the evidence that l8zf nsnep; t(+ight is energy?

Why is light sometimes describcdyv*n/ag6 -e q 8zjs(ed as rays and sometimes as waves?

We can hear sounds around corners, but.wz7. iadre3f we cannot see around corners; yet both sound and light are waves. Explaz7a3.weri d. fin the difference.

If Young’s double-slit experiment were submerged in water, how would the fri a(lfk.) qycs4oq6z+ tnge pattern 6)ak flo +s.qty(cq 4zbe changed?

Monochromatic red light is incienl m -9rltd;29zc) bcd jvn1*dent on a double slit, and the interference pattern is viewed on a screen some di )v1n;- ncl rdbmdj9z9tc*el2stance 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 the same source destructively interfere if their pag j+oak,p2m88vz w2roth lengr2ag8wv2 z+po o8j, kmths differ by how much?

Why was the observation of the double-slit interferencwn8u ejt3n 4l/cko9:z e pattern more convincing evidence for the wave theory of light than the w9n/o :j3zc4nlkt8ue observation of diffraction?

Compare a double-slit experiment for sound4 /2.2dygkvwh-s15j m nqk goh waves to that for light waves. Discuss thekgw5h-djk1sy h/.v n2og 2qm4 similarities and differences.

Why doesn’t the light from the two headlights7 f2a bcfw5za: of a distant car produce an interfer:2f fbzaac7 5wence pattern?

Suppose white light fall 3t8ymv*a w(hj i8 xvpa(av.:vs on the two slits of Fig. 24–7, but one slit is covered by aj*8y(8vxw3a i tmapv:av (h .v red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattern on the screen.

When white light passes through a flys :w7g yw(i jd5j7jem1/t 5xtat piece of window glass, it is not broken down into colors as it ism jw(igtyx/ 15wy75jes:tjd 7 by a prism. Explain.

For both converging and diverging lenses, discuss how tq,1 nwyy1o+k2ri 3coj he focal length for red light differs from that fo jyoq+2ik,c 11y3ow nrr violet light.

A ray of light is refracte86y6yyf z4k 6lailn4 jd through three different materials (Fig. 24–55). Rank the material6ayfnz 4ilyy6k86j4ls according to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a distant light sofq8thhrv2aqc-q6.j ,7cg9zky(. ksh urce through a narrow slit between two fingers. (Adjust your fingers to obtain the best pattern.) Describe the pa-9q.t68sq fkhcqvyrkg2,jhz7 h ca.( ttern that you see.

What happens to the diffraction pattern of a single slit if t q/ewnf 6+rmo/he whole apparatus is immersed in (a) water, (b) a vacu+re /qm of6w/num, instead of in air.

For diffraction by a single slit, what is the e5xd k)x )f0ln;1j bciyhdch11 ffect of increasing (a) the slit width, and (b) the wavelength jyd;x bnhl 1k0x1hcif) c51)d?

What is the difference in the -zxib k mt1l*02ta 6glg tt6*jinterference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grati/ljc (f7cvqy b blx, 2b:;uruh;hh8 i;ng, what is the advantage of (a) many slits, (b) closely cv,q 2yb8lf;h u xuc7ji(rh b:/;;hlb spaced slits?

White light strikes (a) a diffrn7zmx py,j7pfq/rjop2/4 h v-5pqji; action grating, and (b) a prism. A rainbow appears on a wall just below the direction of the horizontal incident beam in each case. What is the color of the top of the rainbow in each4/i ojz;- vhpxpy/ r2qp77mf5, jqjp n case? Explain.

For light consisting of wavelengthskz b5 b43awaejs.8er/ between 400 nm and 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 the slit a ebk485r3jzes/.wab spacing?

Why are interference fringes noticeable only fo;kjul. 213pfbvf 10v5rb oxcqr a thin film like a soap bubble xor2 f fc 01lb35vk; jpqb1vu.and not for a thick piece of glass, say?

When a compact disk (CD) is held at an angle in whlz tv :9k1pl- 3 whj1vh(serymfie/-*ite light, the reflected light is a full spectrum (Fig. 24–56). Explain. Whak3ey v h-rlz11(h: 9- sl* wtjmev/pift would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from6glxbb ,2/cae the center?

Some coated lenses appear gr8/ k 5bj ph :czizi,5t2p6bysweenish yellow when seen by reflected light. What wavelengths do yoyw5 zb,s :5hji6p2/p8tizkb c u suppose the coating is designed to transmit completely?

A drop of oil on a pond aut r1 h .mme-d)1myi:lppears bright at its edges, where its thickness is much less than the wavelengths of visible light. What can you say about the index of refraction he)ummyit-:r .1l1md of the oil?

What does polarization tell us j-isxvx ;enl* my;x) 2about the nature of light?

Explain the advantage of polarized sunglasses over normal tinted sunglasseshh5mt-m 8 qfv )g-vpl..

How can you tell if a pairqz/fg f/sz-) w of sunglasses is polarizing or not?

Two polarized sheets rotated at an 5t(e- jjl lf- yruij45angle 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 Eac3e:d)s jd ikk;4r*av rth had no atmosphere?

If the Earth’s atmosphtb+;(9ra rye:(qfg mbere were 50 times denser than it is, would sunlight still be whitefyr qtabbr(( :+g e9;m, or would it be some other color?

  Monochromatic light falling on t/b bp3 pw66sxl-p5uls wo slits 0.016 mm apart produces the fifth-order fringe /pl wxlb6pbs36p5u -s 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 anh-df/n9 exku6 gle 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 apart. Successive fr/9 qd. :ubdpkljpp*s4inges on a screen 5.00 m away are 6.5 cm apart near the center of the pattern p.: sjp4/*ubp lkqdd9. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of light from a He-Ne laser, with a wavelength 656 l)uuarf4j * c9sst4i0 nm, falls on two veryflst jas40 4i)uuc9* r narrow slits 0.060 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 fsxq 5hcn9q/x*ps9px 2 alls on two slits and produces an interference pattern in which the fourth-order fringe is 38 mm from the central f9csx p9xq2nhs5 p*qx/ringe 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 far a5 nhzpr ki: hfb-rf( 0op4mv5-part are the second-order fringes for these two wavelengtomfriz4pn:b5fh r0 pvk ( h5--hs on a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelev g3re*wq-k;gl8 ct6angth 460 nm gives a second-order maximum at a certain locationr8tl*g- qak3; vecg6w on the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pasj-vwx3n pj h- qi6 (eeqa//2xms 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 wave acqx-qe-(h/env p ja6x iw m3/2jtion?

Suppose a thin piece of glass is placed8i0 y(wktm:v l in front of the lower slit in Fig. 24–7 so that the two waves enter the sl yiktmw: v0(l8its 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 olu :5p+kfs-amaximum for light of wavelength 500 nm is located 12 p:u-ok a5l+ fsmm 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 illuminated u nigej:v(nn-6:jt 4 fby 544 nm light. Find the distance between avji4jn u:-e 6:n fg(ntdjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air f n n asy- 2nhlxjz14eja:do.p3 7f4np1alls on two slits $6.00 \times10^{-2 }\;mm$ 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) covers one slit of a dv p. i;5vy 7d(vviif2pouble-slit apparatus illum 5fvvppd;i2iv(v.i7y inated 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( i o4kusj,aw3 speed of red light (700 nm) exceed that wioau34k (j,sof violet light (400 nm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikes a piece of glass at 0e5jfalnx2z: tu1mz5 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 cur gtnybp +,5zl/76knontaining 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 a6fkzfd1385(ub1khf b1 axa/a nf zl(y slit 0.0440 mm wide, what is the full angular width of the centrbzy5b8f k l1n(kfhz6 f/fau1 1a3xda(al diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a slit thapfn ieo g0l*8g,d+z w;t 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 tlbw fz/-w:3 a1tzr (1c +hcjtfalls 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 by 450-nm xnd c026v(qru+lx8myx5+pkd light. What is the width of the central maxim(rvcyx k0q +5dxx+2l8u d6n pmum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 n6jynfe3z, m7qi7 mc 026p9:-uz/y e wq ovkevtm falls on a slit. If the angle between the first bright fringes on either side of the central ma0w/e6yui27 zc t:7 ojq,veqvze-pm 9mk 3fy6nximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak ono;sh jq5mf00p a screen 2.30 m behind a 0.0348-mm-wid0;smf0 5 joqhpe slit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm fa7uxo 92vh :ovb8i egu i3+p0xglls on a single slit, the first dark bands on either side of c h2: i+9g0g7xv3v oup8xbuoi eenter 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 single slit, it creat1dm9cuf mb26 res a central diffract6fbmr 1 u2dcm9ion 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 4.0 cm wier 0 f mxw6ugr1zl-wp0,f1t a*de on awfgtm-*upl1rer060 ax,zw f1 screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelength 420 nm?    cm

For a given waveleng bo3uk 3oz0j8js5thp3th $\lambda$, 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 maximum wh/ysf, x8lm9,pxwj*v a en falling on a gra/ x,8y9vws pa,fljx* mting 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 gratpan-nv4y 8i px(pbb:+hq2sx o30 gc;king have if the third-order occurs at anpxnb +8: (30kyshxcq-4ipav; gpbon2 18.0$^{\circ}\,$ angle for 630-nm light?    $ \times10^{3 }\,lines/cm$

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

  The first-order line of 589-nm light faltu48d nd3knv6cu33) bvdc 6heling on a diffraction grating is observed at ac h36uddbecv k4v)udn836 nt3 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingu;jess;kp6snsq +- (f 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 rufpw 1q+ nzwuj-7(c,wc nr 05ag1cz*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 i15t( u/4me0uofaaah9f 8v zo gy4a.z6b8dl j tf a grating with 6000 lines per cm is illuminated with 633-nm laser light? Assume normal incizmuu a4/. aalozg1a te08o9 bfd5f8 jyv(t46hdence.   

  Two (and only two) full st0g 3,fdbtmg syvdlbf0e9,m j * b :n3.gn9ik2pectral orders can be seen on either side of the central maximum when white light is sent thr. gj0 9n 0km bgs3923,ftidymget bndvb,*:lfough 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 grating wi ,2 /u,3u.s rzj a70hx)eocmhdg dic1ethdze/c 2euh,37dm .a0)ujc1,xo hg r si $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromati vde*wi8-hmrmff)3+ uuhe)m )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 spect- *egtjg vrzfe3q v.vhe6;v39rum lines 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 wavelength is mh, v;* v;owxaojhad54ost strongly reflected at the center of the outer surface when ilow hoa54v av*x;h ,;jdluminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the de789 sqg w0dkuark fringes in Example 24–8 if the glass plates are each 26.5dk g9u8ewq s07 cm long?    cm

  What is the smallest thickness of ach /pbl8:dqhjo .u8+l soap film $(n\;=\;1.42)$ that would appear black if illuminated with 480-nm light? Assume there is air on both sides of the soap film. $t_min$    nm

  A lens appears greenish kx5i*m wsq y), 8flq(myellow ($\lambda\;=\;570\;mm$ 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 (nwco.i d247 ,qhko7jqdatx34m ot counting the dark spot at the center) are observed when 550-nm light falls normally on a planoconvex lens resting on a flat glass surface (Fig. 2 it4 kcqj7,oh xo.2dqwd 34m7a4–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces ocbp6n ;b9c-yvz+.j cw7 qa+w zf optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark licz za;w7jy.bn wcqv-b6+ p9c +nes are observed (with one at each end). How thick is the foil?    $\mu m$

  How thick (minimum) should;px rmqxyv7 s; 8n, htery4u:f*b/sj5 the air layer be between two flat glass surfaces if the glass is to appear bright when 450-nm light is incident normally?4;njf xsmh/ u;retxbspv *5y7: ,y8q r    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen dia4i(; fuc xm:qemond $(n=2.42)$ 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 alcohol0zhlj h4oijt*c: b/d*cm.tb3rs(nx2 $(n=1.36)$ 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, tspf/waay s 1jr628k5 u1yn.xohe diameter of the eighth dark ring decreases from 2.92 cm to 2.48 cm. What is the refractivea kfjw .y1o2px6 5n8/rsysua1 index of the liquid?   

  What is the wavelength of the li)a0vlm q q +vorl6lr( zj2qym ,4:b1ncght entering an interferometer if 644 bright fringes are countlmno yq4lb,)q:lc2 (+10 zr v6rmaqvjed when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mif. h05n7c cnhs1*/vuyr) cgnsrror 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 27cnvgun /hn1.hr) ss 05*yccf72. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirroyw4oeg- 9d4 ug38v hx +n5sjmnr $M_1$ 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 antvp fai /r- ,f /nm*iojj6xc5( interferometer (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 waverf(- ct*m/i op a fni5vjjx6/,length of 610 nm. Calculate the index of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are orienm2l yoxcw3p 3 4cledzk8jj880ted 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–gla(.;pfa zwwtxx+ze:2 b ss $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond suf( ltf+0d/+4saec xupbmerged in water if the light is hitting the diamon0+xta sc+(fe4uflp/d d $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that thpa;zgy gt 7r52e light passing through them is a maximum. At what angle should one of them be placed so thz7g5grta2; ypat the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two xlorf u u.27p4Polaroids be placed so as to reduce the intensf 2uu7 4rxo.lpity of the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented /s*e mc( )i5 qso04q aygzfcc)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 3dkoxgu-q 10j qw 2**gk; svoc18.0$^{\circ}\,$ 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 ankqw.+np e6gr4tc 1; wkgle be for reflections off the surface of water for light coming from beneath the surface? Compare to the angle for totaln4kgt wq1e c6+.r kw;p 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, 7hbkf cu1so*n/ :*mes each of whose axhs*n/bs ek: 7f*uc 1mois makes a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength m;n1iqk r)i0q4 rkoku3j4 704bo /u svds-ncr$ 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 airplum8 qi6n1(m wyanes can interfere with the direct signal from the station16nmqiwy( m8u.
(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 v1 35 p:dz1yd,)n rnvz ltzodrc:l:3wthrough a diffraction grating with l:tdvnl,zw1d:)3 51yz vdc: 3nz p ror$ 3.00\times10^{5 }\;lines/m.$ The wavelengths of the three lines are $ 6.56\times10^{-7 }\;m$ (hydrogen), $ 6.50\times10^{ -7}\;m$ (neon), and $6.97 \times10^{ -7}\;m$ (argon). Calculate the angles for the first-order diffraction lines of each of these sources. $\theta_{h}$    $^{\circ}\,$ $\theta_{n}$    $^{\circ}\,$ $\theta_{a}$    $^{\circ}\,$

  Light of wavelength 590 nm passes through two narrow slits 0.60 mm apart. Thhi;-ip yb+y zl cx/m)7e screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maximum than the 590-nm ligx-7)+; pi yzhm cyl/biht. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two identic+ok itb6 w-h7(/*k*i,cz hgynnk( og cal 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 +knoz,/yw k hi* cbg-7kng6ihot*c((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/ vqwox0pso cd6,**v agk4s juk :,t9k wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistl sd*g c vq6o0kw:4 taks,9xou*k,pv/je clearly on the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit o+5 kaipehoc,mt .n 4-1wjxsp+ f 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. When0g jukq6odbu 9k/qm;b.9nw z ; normally incident 460-nm light is reflected from the wing, the wing appearskou/ d b qg9kz96mq;0;w.ujnb bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a gratip(c-j0o80dqcb3l ha ong have if there is to be no second-order spectrum for any visible wavel00q- c8 cbo3 jalod(phength?   $ lines/cm$

Show that the second- and thir pjbywxp-6zq5x;6z*o d-order spectra of white light produced by a diffra wo qy*b;xpp6zz6jx5 -ction grating always overlap. What wavelengths overlap exactly?

  When yellow sodium lighk o4s) 3rf 4cssaip q)y)c*n,tt, $\lambda\;=\;$ 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 the5jr:/may:wm lg3.bvke bo-m yb-kl58 pattern is viewed on a screen 2.5 ga:w. /bmb- y3m-5jklemy :k5ovl8brm from the 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 if a minimum of 150 nm w4 z zeb1bk1.athickness of it, when laid on glass, is needed to reduce refl ezb.1bwa1 z4kection to 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 incident normally on a thin/:es+cufv.pnrwrl xla(s ;(. sheet of plastic film in air. The reflected l :.rv.fx +p( ln elws;a(/cursight 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 neednuq6j6 (wpw ne w9s1+ved 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) t 2fg3s10 1l z,wi,eru, y-esqzhft o0ohickness for the air layer between two flat glass surfaces if the glass is to appear dark when 640-nm lightit f1 ug l, sf ,zzerqo,s00ey2o1w3-h is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin film layered on a flat l xstk 70y/6czpiece of glass.ytl /xsc0z7k6 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 relative size of the minima compared to the maxima and to zero.
24-30
24-36

  At what angle above the horizon is-t6d ls2es+wu 6fv(sl the Sun when light reflecting off a smooth lake is polarized most strs -sfsu6(+2 dletwlv6ongly?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so as to reduce the pj-hd44y im/c: ius* pq-vocxa:nc(1 intq*ymi n4cc- u1vsp 4:j(hc-:a xd/poiensity of the incident unpolarized light by an additional factor (after the first Polaroid cuts it in half) of
(a) 4,    $^{\circ}\,$
(b) 10,    $^{\circ}\,$
(c) 100?    $^{\circ}\,$

  Unpolarized light falls on two polarizer sheets whose transmission axes are lhn0w*yr-j(kn l vu(g0k(;y svei;u - at right angles. A third polarizer is placed between the first two so that its ax; v0h*;k wn0i((k ylynjeu s-rvug(l- is 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 f;hiof,c)d1h/q4n j lnsmmt3(2u(z ttheir 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 pointed6 lhwukn upy 8/7u)7bb at the Moon, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red liub7ykuh8 w/7l)un6bp ght of a He-Ne laser). Estimate the width of the beam when it reaches the Moon.    km

  A series of polarizers are eachu- qzc:sskx :5 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 w66: c/llx q+darf.z;ulr0cq $(n=1.34)$ 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 x,t(z.tk .x qn+26 flvrdzy *xin phase with each other. They are located at poi*q+drv x2xz y.ltxk ,n ztf.6(nts $S_1$ 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 wave o6* 4itgd(zxo9z9a)vugskg*t 6qh t4lengths, 420 nm and 650 nm, enters a silicate flint glass equi *auigqthx 4 96zv(t6)ts9kd4*zgooglateral 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 e/ lsdek -8rb,k -)ubrlens 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