Does Huygens’ principle apply to sound waves?4 s-wug2eqc if4x9mz4 To water waves? Explain.

What is the evidence thm7ham 6reg8a w**,p yt+qsytqe*: (sg at light is energy?

Why is light sometimes described as rays ak;9nm7n. lh- e7gzc mbnd sometimes as waves?

We can hear sounds around corners, but we cannot see around c*/ylr3m+m uw nq+d 1s0doyrr 1orners; yet both sound and light are wavedrnwry3q/msy10* ro l1ud+ +ms. Explain the difference.

If Young’s double-slit experiment wer*:7 jvy9o how-o7h wane submerged in water, how would the fringe pattern *h9o 7ha -7ov:wonj ywbe changed?

Monochromatic red light is incident on a double slit, and the interferen5lbdkhle ,gsm 98q -p( nvz--fce pattern is viewed on a screen some distance away. Explain how the fringe pattern would change if the red light source is replaced by a-(qh 8,9skvf em5-dzblg-lpn blue light source.

Two rays of light from the same source destructively interfere if theaynv+9 :1s j1teyqx)y ir path lengths differ by how muj q9+) a1:ysyvynex1 tch?

Why was the observation of the double-slit interference pattern morj4gkz5; gf3lte convincing evidence for the 35jlzk4g gt f;wave theory of light than the observation of diffraction?

Compare a double-slit experiment for sound wav*-l r/hak8 zcpes to that for light waves. Discuss the similarities and diffez* -8chpr/aklrences.

Why doesn’t the light from the two headlights of a diqsl6;u *gc*z,bi;4 aa p1ny orstant car produce an interfeg * ,z1pncryuaqi;b64 l*oas; rence pattern?

Suppose white light falls on the two sli7d*-l5doweoceq/p a ;r .ypz6ts of Fig. 24–7, but one slit is covered 7l r e./ 5d-z*oapy6;w pdcoqeby a 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 flat piece of window glass, it is not broke+-jhadg goaw gn0jfwi.)6x)) n down into colors as it is by a ga gw)-6g+ hoaijw)0nd .)fxj prism. Explain.

For both converging and divcmhd3ffa1ccbkux(3a1 2 1j7ktfw )m ) erging lenses, discuss how the focal length for red light differs from that)ccf7bkhk uw dmc 13)ftx1a j( fam231 for violet light.

A ray of light is refracted through three ipsikd(rar/b 2,cq, wmj,/; i) qiq(x different materials (Fig. 24–55). Rank the materials according to theiq/q xb i,;isiw)qj ,pi/cd, r(r 2akm(r index of refraction, least to greatest.

Hold one hand close to your eye and foc*- ;voy ix x40qbdr u3/,+yavf a;ovnsus 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 si o0 + ;a,d/ vrvvyyf;n3s-x4oqbxau*ee.

What happens to the diffraction pattern of a single slit m*63;pp uaa)av l tey-if the whole apparatus is immersed in (a) water, (b) a vacuum, insp )u*ptl -ayemva a36;tead of in air.

For diffraction by a single slit, nwzs6ltj c /8+2zup(mzis q ;+what is the effect of increasing (a) the slit (6nt+ zicu8sqm lzz2;/swj+pwidth, and (b) the wavelength?

What is the difference in the i l r 7+n*1ule3jgxhec4nterference patterns formed (a) by two slits $^{-4}\;cm^2$ apart, (b) by a diffraction grating containing $10^4lines/cm$?

For a diffraction grating, what jeg8p ko( (xz8is the advantage of (a) many slits, (b) closely spaced sloxge 8pzj(8 (kits?

White light strikes (a) a diffraction grating, and (b) a prism. A rainbow appear:xnxcm-ct--i:2mn uts on a wall just below the direction of the horizontal incident bean:t-cx mx:mi-u tc -n2m 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 normald0mf++4*hrru k:f: ,ia nac loly on a d: rad*m o0fkn clh:ur+ifa,+4iffraction 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 q/3f*c:+ nk kb3jqjp9l0dvf lnoticeable only for a thin film like a soap bubble and not for nlbj* 39 vfp k:/lfc+j0d3kqqa thick piece of glass, say?

When a compact disk (CD) is held at an angle in white light, tqrn1q+j 5n/ kpj,fky3he reflected light is a full spectrpkjyqfk+13n,n / r5jqum (Fig. 24–56). Explain. What would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together farther from the centeyi0 ( kp1mpgb9fw/0rgxlsbt/ q +j1,lr?

Some coated lenses appear greenish yellow when seen by reflected liriwy, m qfypa( * bhkr:o:,l/+ght. What wavelengths do you suppose the coating is d,,ypi+ yklr rbqa/:oh :mwf *(esigned to transmit completely?

A drop of oil on a pond appw9 j ki2 cmucr;re8wk,1g5/drears bright at its edges, where its thickness is much less than the wavelengths of vis;9k 8ujr/wekcmr 1drg ,5i2c wible light. What can you say about the index of refraction of the oil?

What does polarization te w.zxmk k+-; 78 5mt(rmvwp97yqj nmefll us about the nature of light?

Explain the advantage of polarized sunglasses over normal tinted sunjyjf+s9m;h. f u6hbm- glasses.

How can you tell if a pair8rjabaxq )592s0zwr h of sunglasses is polarizing or not?

Two polarized sheets rotated a qmi3;b* 5rget4 f)chdt an angle of 90$^{\circ}\,$ with respect to each other will not let any light through. Three polarized sheets, each rotated at an angle of 45$^{\circ}\,$ with respect to each other, will let some light through. What will happen to unpolarized light if you align four polarized sheets, each rotated at an angle of 30$^{\circ}\,$ with respect to the one in front of it?

What would be the color of the sky i9l 6)8oq y4ewf4ygd owf the Earth had no atmosphere?

If the Earth’s atmosphere were 50 time6 fx+lalgcys9j1rgwvg qpvk )y,f4; wf ,s59(s denser than it is, would sunlight still be wy g,wy4 w9gpvl (flfvj6s c1;qasx)kr5g,+f9 hite, or would it be some other color?

  Monochromatic light falling on two slits 0.016 at2sxl k+q:t. mm apart produces the fifth-order fringe at axks. tqtl :2+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 oq9s psk8msx;4r x 8x;l ck*am9f 18$^{\circ}\,$ when the light falls on two narrow slits. How far apart are the slits?    $\mu m$

  Monochromatic light fall-m : -iqesigvimt:g 9;s on two very narrow slits 0.048 mm apart. Successive fringes on a screen 5.00 m away are 6.5 cm apart near the center of the 9is;:g m -mqie tv-:igpattern. 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 65 lgzdi5+ )wuo,6 nm, falls on two very narrow slits 0.060 mm apart. How far apart are,wo5 uil +dz)g the fringes in the center of the pattern on a screen 3.6 m away?    cm

  Light of wavelength 680 nm falls on two sx *4 qkxy25l+lz6x6 srste2 peysl,7plits and produces an interference pattern in whip4llqekxes,p25y +r 2x *y s6stl 6x7zch 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 far an falc*p r(gb 0d.:p:mpart are the second-order fringes for these two wavelengths onl0rbcdfgm*.np: ( a: p a screen 1.0 m away?    mm

  In a double-slit experiment, it is found that blue light of wavelength 460 nm f3uqk8n- *cu +o /yn 3*ddgtcugives a second-order maximum at a certain location o*8 k-dy33d+tucnf /uncogq *un the screen. What wavelength of visible light would have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apdppo7 :v4,7ajjwl6zg art pass through two openings 5.0 cmd jjlz 7:6p7waov,pg 4 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 action?

Suppose a thin piece of glass is placed in front of f.o wz2xd5k06ks; vqkthe lower slit in Fig. 24–7 so that the two waves ent.k skwz52f kq; od6v0xer 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-ubq:9:5k)t56 cevxacjh-kes order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will the second-order maximum of this light k-jxk e5sha:6 tqb5ec)9 v u:cbe located?    mm

  Two narrow slits separated b)b /1k l4xlrncy 1.0 mm are illuminated by 544 nm light. Find the distance betw b4 ln)kl/rx1ceen adjacent bright fringes on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls on tvmnr o56 c,b a5m9x7 vizjh9q9a v7rv6(guy m-wo 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 r4s 2nh)62r,o+hbaie eg4jamdouble-slit apparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. Whatraahem4 r) iosjehnb6 +2 ,24g is the (minimum) thickness of the plastic?    nm

  By what percent, approxi-gz)yv)n ph3xmately, does the speed of red light (700 nm) exceed that of violet light (400 z-pgh3x) ) vynnm) in silicate flint glass? (See Fig. 24–14.)    %

  A light beam strikesge -x)bj tfo+9 a piece of glass at a 60.00$^{\circ}\,$ incident angle. The beam contains two wavelengths, 450.0 nm and 700.0 nm, for which the index of refraction of the glass is 1.4820 and 1.4742, respectively. What is the angle between the two refracted beams?    $^{\circ}\,$

  A parallel beam of light containing two wavel kf :usmvol723.gic 3bengths, $\lambda_1\;=\;450\;nm$ 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 0.0447)unm 6lu.bwcn gke d* w(5kv c(-uqt80 mm wide, what is the full angular width of the centr d 7wb*knc6u tuqc-.egk)(v m5w(ul8nal diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on -f2:w ** sdvregoks i)1n6f l- dj6ppwf gln1)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 520 nm falls on a slit thhy:z5t +nh o/b+ybi4 uat 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 illuminaxqjq jt7 6xnvea;4x58ted by 450-nm light. What is the width of the central maxim 5 4ej8xxt;jqa67vxnqum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of w.8/k7wu x4t jd(izoevc24c/x cy k2nn avelength 653 nm falls on a slit. If the angle between the first bright fringes on either sidejkz4ucx/ 2cx87 kdetw4 nn2ovc.iy/( of the central maximum is 32$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a screen e,+9kc2q (ef gl).k v;hn dygl2.30 m behind a 0.0348-mm-wideg.d+e l)9(kfcklg2h;v n q,ye slit illuminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falf( or7di. dgm:ls on a single slit, the first dark bands on either side of mgf:.di rd(o7center 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 creates a cen)0+sx+a7jykyip o/7 k zod 1sitral diffraction peak that is 9.20 cm wide on a screen that s0+po/zk y ij7koidx)ys7a 1 +is 2.55 m away. How wide is the slit?    mm

  If a slit diffracts 650-nm light so that the diffractpx(,9ppq9d)h9rrq1 k b b yo+pion maximum is 4.0 cm wide on a screen 1.50 m away, what will be the width of the difpb9qpr,dq(1kpybr9px+ ho )9fraction maximum for light of wavelength 420 nm?    cm

For a given wavelength x wl1b, cfi5kg(qtn)b/9 psw6 $\lambda$, what is the maximum slit width for which there will be no diffraction minima?

  At what angle will 560-nm light produce a sew q9tll4fqqhr l/ x7r/lt.l)7cond-order maximum when falling on a grating whose t.)/qf4l 9hrlllrq/lt7 wxq7 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 if pgt hanezy m3x8k.y31)2e j,gthe third-order occurs at anxmzh j82.) e y neg31tyg3a,kp 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 58,0ml4cblp+ysvy)e p 7 x7k4+o2pro ds9-nm light falling on a diffraction grating is observed popmdl,y p4c br++ x4 ks27v 0e7syol)at a 15.5$^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingdbl5+- 62l8n wqunnlp 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 bwir jt*v0(6p 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 6000 lieo/80btb/8d,rk( ad jqmt .iztx2 ws0nes per cm is illuminated wit8eb,qxozdw0r/t s (2km0bd /iatt. 8jh 633-nm laser light? Assume normal incidence.   

  Two (and only two) full specx-irh/,zbv y u:roi (qyfi06wmnr799tral orders can be seen on either side of the central maximum when white light is sent through a diffractionzri,r7qi9 x/vfhw b 9:-uo6(0y inmry 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 fallt8g5plnq jg o; yf eg,w:32/gks on a grating with 3lgyg ;ekt28g/qofgw,5:jp n $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which pun egocs7og*.-/5 q an ylx8crf1w /k-roduces monochromatic 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 measregvy,vsm-7aa8 )2f bured 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 6cy-3n2 ; yz1jc3ykt.oq qhpznm thick, what wavelength is most strongly reflected at the center of the outer surface when illuminated normj;h13 ycy.y c6otz3 2-zp kqqnally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are the dark fringes in Ex45txxxdazzr)t: 80c/wb jb +h ample 24–8 if the glass plates are each 26.5 cm longw dbrz)/+xc ax0tz:x4j tb85h ?    cm

  What is the smallest thickness of a sc) ;g0gi6xwd joap 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 yellow (xx :uqdbb8usah:tkp a14 * 8q($\lambda\;=\;570\;mm$ 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 Newto:4tlt0tqpk:o ; dsl 6e e.ep0xn’s rings (not 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:e0 xtqple46lsp .k:t ;o0d et. 24–31). How much thicker is the center than the edges?    $\mu m$

  A fine metal foil separates one end of two pieces8rym : hps25k ljzk9(k of optically flat glass, as in Fig. 24–33. When light of wavelength 670 nm is incident normally, 28 dark lines are observed (with one at each end). How tjph k5kymz8l 2 sr(:9khick is the foil?    $\mu m$

  How thick (minimum) should t53o f2lkc 2u;swenh)k he air layer be between two flat glass surfaces if the glass is to appef2k h5keon)sl;cu w32ar bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of materialei,r xg5 (m5d dk)yk-khii/ b7, suspected of being a stolen diamond $(n=2.42)$ is submerged in oil of refractive index 1.43 and illuminated by unpolarized light. It is found that the reflected light is completely polarized at an angle of 59$^{\circ}\,$. Is it diamond? ----待选择----yesno 

  A thin film of alcoho,tmmv kt6akl;.l* y:cl $(n=1.36)$ 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 inc3a 0hg9oop )f a liquid, the diameterpch3 9 o0oa)fg of the eighth dark ring decreases 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 inte;vdn4znqy, vpcc+ p3-nam0k s)4: vmarferometer if 644 bright fringe-a dc+0sny4acvm k4:)v ,vqppznn m;3s are counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to the movable mirror ow++1-o2 qilisu g3m3vluh6+.uxndquf an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, csu .-gni3+ o qx+mdl3+luhiv1u qw2 u6ompared to the empty micrometer, is 272. What is the thickness of the foil? The wavelength of light used is 589 nm.    $\mu m$

  How far must the mirrorff7 +4.bc 5g2v*zz vnkt s4qywk.rw* g $M_1$ 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. 24–5n /qblgyyr694ji fn:,y:,fli9) 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 referen ffgrilynqli:,69:y4 jn ,y/bce 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 orie,y6e.igv8s y nnted 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–glass ;bb(s lqjd 3*v17b jw b+tncxfa3.nw33.yowh $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a diamond submerged in water if the light is hudo g5gdx,..y itting the diamondydd u,.. gx5og $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them is a maxg,z:a)3f1t xdwe ad 9eimum. At what angle should one of them be placed sad3 1ad,xg9)z :fetew o that the intensity is subsequently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be placed so au ;ru-+y4x(v wcsxf fc/ rfc-/s to reduce the intensity xvr wc-s /+;r4 xu(yc ufc-/ffof the incident unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are oriented b2vtnk6p* 5 m+rmz4 tmat 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 oriejh+en :r(d4xj1, czvi nted 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 w(+bwzbrw8hwwsq/ 6 o7ater for light coming from beneath the surface? Compare to the angle for total internal reflection, and to Brewster’s angle from above the os/w+zw7q6(8w hr w bbsurface.
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 thqi/(6 f1anxg6ty * mfqrough five successive Polaroid sheets, each of whose axis makes 6xq(ny6 fgmif/ a qt1*a 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength pppsd qr39h,w./1wa y$ 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 ca9 1o0 9pa h*/enozojnfn interfere with the direct signal from the statiopn*910z ea/jo h9oonfn.
(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 aq qr2 h1lu (u5bu7d.zt diffraction grating with .r h udz2 q571uutblq($ 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 pasb+djy/ a7si; ases through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength produces its second-order fringe 1.33 mm closer to the central maxjas/bdi7y +; aimum than the 590-nm light. What is the wavelength of the unknown light? $\lambda_2$    nm

A radio station operating at 102.1 MHz broadcasts from two identical antennaea co d.+lf6tpt,4tv0b at the same elevation but separated by an 8.00p lo+6v4,fbt ct. adt-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 doorwaw pu*i- bzji52 hx(i-vy 0.88 m wide, and blows a whistle of frequency 750 Hz. Ignoring refle-zp 2uhijiib (w*-5xv ctions, 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 fallp3ue 7zeyv31x) f;mk gs on a single slit of width D at a 30$^{\circ}\,$ angle to the normal, describe the diffraction pattern.

  The wings of a certain beetle have a series oowct 5kd-f--rf parallel lines across them. When normally incident 460-nm light is reflected from the wing, tk-fd5w-o tc- rhe wing appears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a grating have if there is to be no s 1l:c --priltbecond-order spectrum for any visible wavelengthtc -1:lbipr-l?   $ lines/cm$

Show that the second- and third-order spectra of white light pr)-eppqh lwq3 7oduced by a diffraction grating always overlap. What waq3pwe 7lpqh )-velengths overlap exactly?

  When yellow sodium light4ght( o uybmx(7l.p q5, $\lambda\;=\;$ 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 diffractio/n a *l yxo3ob1n.r6gzn grating with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam aor.lx 1z6nb ng/y* o3consists 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 cleg8 ,9jjsq 6 .9grhd a+u9m gnx./wtasear material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflec, a. rs uhx8jqgw6d .tsem9 gg9n/9ja+tion 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 wave bev46(a yq:+-bhtzxdlength is incident normally on a thin sheet of plastic film in air. The ze yx-(:q b vtd+ahb64reflected light is a minimum only for $\lambda\;=\;512nm$ and $\lambda\;=\;640nm$ in the visible spectrum. What is the thickness of the film $(n=1.58)$? [Hint: Assume successive values of m.]    nm

  Compare the minimum thickness needed for an aga*o or8;euy usg 1lt(-o,iq;nti-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 flam5ingh5 37 x l3usl5bbt glass surfaces if xs3g7bmh5l 3biu55 lnthe glass is to appear dark when 640-nm light is incident normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted through a thin hip .(6bgqv8keux)b8film layered on a flat piece of glass. Draw a diagram, similar to Fig h8p.i bgqbv)(e6xu8k. 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 the Su+9ctw wqd .s(a.dk,zan when light reflecting off a smooth lake is polarized mostwqa9dst . wck.dz+( ,a strongly?    $^{\circ}\,$

  At what angle should the axes of two Po*gul3r;+nn;y j qj/ hrmay/ -4wpa5gvlaroids be placed so as to reduce the intensitggr *3-a4pyna l; h;+5 n/vywrmj/q juy 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 at rn e)j nz5i2hf7ight angles. A fznn25)7hie j 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 axes ver.zz:msys ob:7pr)-f e tical, 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 12qk( rkvf** ve.0 cm and is pointed at the Moon, which is approximatelyk* r2kvveq (f* 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 each placed 3m eteci ez8yb+rj(3;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 zbm+pujc/ea h7z5.o3 $(n=1.34)$ 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 wavesma n v0k4gn,)gag1hv6*i(mojf0i z3i in phase with each other. They are located at pa)m6gi, v40hv ( zamgj*kni 0gn 1i3fooints $S_1$ 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 nm, en 8en)a -drootj3m;w )pters a silicate flint glass equilateral prismmo)j;-dp)3oa et r nw8 (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 hah,:b j4qv*g*wgblb.o z1llqf 61o n- zs 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