Does Huygens’ principle apply to sound +,5 ;7l n*wespoik p 9tzq(ctbft3*gdwaves? To water waves? Explain.

What is the evidence 1scz.0m0yk c x:i3uz9.ahw4 sv od:agthat light is energy?

Why is light sometimes described as rays and sometimes as waveum6j;h )l lk5bs?

We can hear sounds arq h/ t8we1dt5x:+itrbound corners, but we cannot see around corners; yet both sound and light areqb/ett+5r8hxd 1 i:tw waves. Explain the difference.

If Young’s double-slit experiment were submerged in water, how would ta(8vh ,a hlqll;zvb (g 3dms(jm)2lk6 +y:jpthe fringe patteslhjzbh),jaa8qy 3gml:dl6 mtv v(((;l +pk2rn be changed?

Monochromatic red light is in sx auvup v,r:2wh27;pcident on a double slit, and the interference pattern is viewed on a screen some distance away. Explain how the frix rw 2,s; vapu:uv72hpnge pattern would change if the red light source is replaced by a blue light source.

Two rays of light from the same sourceje j ;- *lx3mc.psb.mp destructively interfere if their path lengths differ bmbc .pl3-.x*;sp ejjm y how much?

Why was the observation of the double-slit intet(b r yp2zf24(xos8 ekrference pattern more convincing evidenszkrt2 e 248b(p(xfy oce for the wave theory of light than the observation of diffraction?

Compare a double-slit experim1iv 02(pgox(ujs8f+ihe a ob;ent for sound waves to that for light waves. Discuss the similarities anasgej(021 8+ioo(f xvp u;ihbd differences.

Why doesn’t the light from the two headlights of a distant carokd aj-.. oy316wi a2avr 1auj produce an interference uao-3 j1 jv yai21a.akr6wod. pattern?

Suppose white light falls on the two slits of Fig. 24–7, but one slit is covrispy3;+ 15kese /f alp4;xaa ered by a red filter (700 nm) and the other by a blue filter (450 nm). Describe the pattepla 1;ary;5 si/+4ep3 kxesafrn on the screen.

When white light passes through a flat piece of win8mhltd5nn-9 ,an w,wb )(jgr sdow glass, it is not broken down into colr ahl5jbtn89 g- ) ,s,m(nnwdwors as it is by a prism. Explain.

For both converging and diverging lenses, discuss how thl4e; mf1 fl0grt29t d1.hmhz pe focal length for red light differs from that f1. ldt;lfh19gzmft4mr p2eh0 or violet light.

A ray of light is refracted through three different materials (Fe+gi l g 8acnzwk 6*7.hb hs:33eznjn.ig. 24–55). Rank the materials accordink i7.e. n:3hglszn8ec j6hn b*zgw+3ag to their index of refraction, least to greatest.

Hold one hand close to your eye and focus on a dismo j4 xvxk,35itant light source through a narrow slit between two fingers kxmv,i45 oxj3. (Adjust your fingers to obtain the best pattern.) Describe the pattern that you see.

What happens to the diffrrej m ;r6hg2 w upo8v:fafs,)0action pattern of a single slit if the whole apparatus is immersed in (a) water, (b) mu0w, ajv:s pre2h6;r)ffo8ga vacuum, instead of in air.

For diffraction by a single )gf fp -zeqxg+td/* qvi)b:o9bpw8y8slit, what is the effect of increasing (a) the slit width, and (b)9 fvw-8qgpzt)bfbq* +:)piy/d x go8e the wavelength?

What is the difference in the interference patterns formed (aqdg,nutli ou7 + (,vc0) 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* hge35d; ekmg slits, (b) closely spaced slime ekdg* g;5h3ts?

White light strikes (a) q5/sro6so siy+ hj h/u:51rnu a diffraction grating, and (b) a prism. A rainbow appears on a wall just below the direction of t:shi 56nuy1osrjh+q5rs /u/ o he 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 nog38 rfrflbc6n 1nas66 rmally on a diffraction grating, for what orders (if any) would there be ovclrng sn66 1f3 68fabrerlap in the observed spectrum? Does your answer depend on the slit spacing?

Why are interference fringes noticeab(z*;r a.q exr -wu43gjqc5cbule only for a thin film like a soap bubble and not for a thick pieceuzcag*(j 3 wqer -x;5r bc.4uq of glass, say?

When a compact disk (CD) is held at an angle in white light, the reflected ligukr vw4 vu:x3n h5bg1:ht is a full spectrum (Fig. 24–56). Explain. Wr kg:x vwun 34uv5h:1bhat would you expect to see if monochromatic light was used?

Why are Newton’s rings (Fig. 24–31) closer together fakiz jba5a: e.*rther from the center?

Some coated lenses appear greskwc3si 48*gz/kz5ssdd )u ffe6 2n pt4 u/p+lenish yellow when seen by reflected light. What wavelengths do you skpdsf epzn3 2dl*8s s6g54iu)s zfu /tk /w+4cuppose the coating is designed to transmit completely?

A drop of oil on a pond appears bright at its edges, where its thickness iskgyp ltw ,kop(j*act8i6h;0b 9nzq4 ( much less than the wavelengths of visible light. What can you say about the indel(49(q60 c* tn,a;t zkkgopjw8pbyi hx of refraction of the oil?

What does polarization tell us about thecoxr8,git6 :m nature of light?

Explain the advantage of polarized sunglasses 68 zmwsdxdc-h 1w7ti:t+xc /u over normal tinted sunglasses.

How can you tell if a pair of sunglasses is polarizingb5 p x;e1o*o nirwq+-o or not?

Two polarized sheets rotated at an angt 6j .5czar+txle 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 thek2crz pbky6x. 6f1yged af5(5 Earth had no atmosphere?

If the Earth’s atmosphere were 50 times j:q9l. hx+h)8h uhcta denser than it is, would sunlight still be white, or would it be some other colorhu)8ch lat.x:9hh+q j ?

  Monochromatic light falling on two slits 0./7 em3nd ap1ik016 mm apart produces the fifth-order fringe at ak na7m3e di/p1n 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 anglez* xp ox4m;hr,,;cn)w veqvf) 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. 8xo9 e(j*mr) o)qmz vdcy75uhSuccessive fringes on a screen 5.00 m away are 6.5 cm apart near the cent( oxe j dm 8m7q9hr*u))oc5yzver of the pattern. Determine the wavelength and frequency of the light.
$\lambda\;=\;$    $m$
$f$ =    Hz

  A parallel beam of ligh*ie/ 1 - .iv;x7yu )m8j,mvukh gqkaret from a He-Ne laser, with a wavelength 656 nm, falls on two very narrow slits 0.060 mm apart. How far aeqyxgu7)e vk1k;u*.mv im ,r/ha-j8ipart 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 slits uo.gv:+ga 1/nzw s,q7zumx2sl 5+kr xand produces an interference pattern in which the fourth-order fringe is 38 mm from the central fringe on a screen 2.0 m awa7u 2kgsz5/agsx+ ouz.l +qv1w:xrn ,my. What is the separation of the two slits?    mm

  If 720-nm and 660-nm light passesturrv;r d9,v hyhzt + /-7i0rq through two slits 0.58 mm apart, how far apart are the second-ou7rz thdr,- /vt;y+h0rv i rq9rder fringes for these two wavelengths on a screen 1.0 m away?    mm

  In a double-slit experiment, it isd5+nbg j+w mp16m 9,pmyh7 lut found that blue light of wavelength 460 nm gives a second-order maximum at a certain location on the screen. What wavelength of visible light wouly,b+phmj79 p5mg w16 ud+tnlm d have a minimum at the same location?    nm

Water waves having parallel crests 2.5 cm apart pass throu7oe l co s39jjjp jv92a mwmg48f8e.qdx k1r(4gh two openings 5.0 cm apart in a board. At a point 2.0 m beyond vjjpjmaejmlksd 23 c f r9w9o1 e(g84o748xq.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 the lower slit in 6 jbvnbu54w,7ahsb 6mFig. 24–7 so that the two waves enter ts w ab,6jhbv56mb4u7nhe 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 experi-g a9z-l mz2y7 dgwxbb:xxf u2vz*:6iment, the third-order maximum for light of wavelength 500 nm is located 12 mm from the central bright spot on a screen 1.6 m from the slits. Light of wavelength 650 nm is then projected through the same slits. How far from the central bright spot will7gwxu-zzix 2ym-xv ag:z2* 9bd:fb6l the second-order maximum of this light be located?    mm

  Two narrow slits separated hqo/la1i :bjo -n e*b)by 1.0 mm are illuminated by 544 nm light. Find the distance between adjacent bright fringesob: 1aio-lheq*b/jn ) on a screen 5.0 m from the slits.    mm

  Light of wavelength 480 nm in air falls oncrq2f g91pyk ly3o7+g 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 double-slit nc t 2d 7kn9nymr+jvrow-kr *; /j28oyapparatus illuminated by 640-nm light. The center point on the screen, instead of being a maximum, is dark. What is the (minimumncow*-+j 2vkn ktry78o;2 /yrn dmr9 j) thickness of the plastic?    nm

  By what percent, approximately, does the speenzxnrp.u./sya/c,wb9f 0izs 8 jo 59g d of red light (700 nm) exceed that of violet light (400 nm) in silicate flint g c/. a9snf.9w8, bijpz50n xrg/y szoulass? (See Fig. 24–14.)    %

  A light beam strikes a z5njdr cyvmy;x/t1hx(xj.op jm *+b;e5e s9 2piece 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 wavelen6 jm fprzkpz:i2l i89-gths, $\lambda_1\;=\;450\;nm$ 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 fullv lw4geu 1.0qrhy;e -fzt+ut+ angular width of th f;eu .rwzg-eh01tlu+4v +yqte central diffraction peak?    $^{\circ}\,$

  Monochromatic light falls on a sp 55esn4 /x7hx qr irimqa/q:3lit 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 uetkp .-woob ok. 5m;-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 by 450-nm light. What is the widthdux2p +ji6e o a;:goh/ of the ce;d uh :a+ep/6xojog i2ntral maximum (in cm) in the diffraction pattern on a screen 5.0 m away?    cm

  Monochromatic light of wavelength 653 nm falls on a slit. If the angle betweed)37o*dl rng9db s2gfn the first bright fringes on either side of the central maximum is d7 d bgd2l)nr fs*go3932$^{\circ}\,$, estimate the slit width.    $\mu m$

  How wide is the central diffraction peak on a scree zg1j-mnc*cnom xx,2 r8m+:men 2.30 m behind a 0.0348-mm-wide slit illue*c1z2m n,om8g- :xcj+mrm x nminated by 589-nm light?    cm

  When blue light of wavelength 440 nm falls j(h- yotpy6v7u** vuj on a single slit, the first dark bands on either side of center are separated vuv6you*h7*tyj- ( jpby 55.0$^{\circ}\,$. Determine the width of the slit.    $ \times10^{-7 }\;m$

  When violet light of waveleql 63faf0 u7jl3qd2kd ngth 415 nm falls on a single slit, it creates a central diffraction peak that is 9.20 cm wide on a scree q2 ql a3l3kdffj0du76n 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 -qxmg mr+njv a os;if+b9vwx3,56,og wide on a screen 1.50 m away, what will be the width of the diffraction maximum for light of wavelemvfmb x6i+ qs 3x;,ogwo +n9-arj5,vgngth 420 nm?    cm

For a given wavelength,btjcw;;u0o fft,ic w 3 pm.b-;.y nnq $\lambda$, 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 when falliv 2hld-zc0n *+bzv*b cng on a grating whos*v-* 2chc0+ vlzzbd nbe 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 the third-order occurs aklen x0c2ax -,t an 18.0, cn0-x2kxe al$^{\circ}\,$ 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 lightetxzia :8d: 3b falling on a diffraction grating is observed at a 15.5 za::8dteibx3 $^{\circ}\,$ angle. How far apart are the slits?    $\mu m$
At what angle will the third order be observed?

  A diffraction gratingle w/nw3aw(aln -7om5 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 on a 6zunbmycd+ 65 $9700-line/cm$ 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 th:wu9x s 7/kyzbat can be seen if a grating with 6000 lines per cm is illuyk /7b9w:u szxminated with 633-nm laser light? Assume normal incidence.   

  Two (and only two) full spectral ora, 34f slpqe.mders can be seen on either side of the central maximum when white light is sent through a diffraction lq.4ams3,pefgrating. What is the maximum number of lines per cm for the grating?    $ \times10^{ 3}\;lines/cm$

  White light containing wavelengtho-u czu8zv fp7057ur bs from 410 nm to 750 nm falls on a grating withcr8fbzpu5oz7 7u- vu 0 $8500\;lines/cm$ How wide is the first-order spectrum on a screen 2.30 m away?    m

  A He-Ne gas laser which produces monochromi ;(nn, hv60q4bwlq smatic 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 linesq*m+0tzssk2jjl 2.r t 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 mo7bww*r)h xdy8ah qyv e0f1 i* )1am1plst strongly reflected at the centhfd a) w*rqhyypwemvb*78 0i )1xl1a1er of the outer surface when illuminated normally by white light? Assume that $n\;=\;1.34$. $\lambda$ =    nm ,which is an    -  

  How far apart are theg b;6+dt lo4+9ihdv,rcv c zl1 dark fringes in Example 24–8 if the glass plates are each 26.5 cm l9l 4bdc+ghvdo1v i z 6;+ctlr,ong?    cm

  What is the smallest thickness of a soaylsv bs7wd r5.zia4 9d9k*a) xp 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 yelldbf p2j:b(,t.8*r x,yf,f, wa uwpayoow ($\lambda\;=\;570\;mm$ 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 Newtonoi,4pwo:qe9 y’s rings (not counting the dark spot at the center) 9 ieoqp4wy,:o are observed when 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 pihht2t 6xqd6)kk.u8iv eces of optically flat glass, as in Fig. 24–33. When light of wavelength 670 2uhhd6k.v x8 6tqit k)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 the air layer be between two flat glass surfaces itxbi8 f. ew3a5f the glass 8 .ifeb w5tax3is to appear bright when 450-nm light is incident normally?    nm
What if the glass is to appear dark?    nm

  vA piece of material, suspected of being a stolen diamoo9ka9pir 9l;ll1 vc5 gnd $(n=2.42)$ 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 ml2nf vn vo:67$(n=1.36)$ 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 ocli.(g04ss0res4c0 fdh-z h:bl) ee immersed in a liquid, the diameter of the eighth dark ring decreases from 2.92 cmi:0 0hh(-e4edbg)s4cl.ozlsr0cse f to 2.48 cm. What is the refractive index of the liquid?   

  What is the wavelength of the light entering an interferometer if 643(un3ccw n (qf4 bright fringes are f(3 c3(ucqnnw counted when the movable mirror moves 0.225 mm?    nm

  A micrometer is connected to thdtzxd.(vqof exlz2uy8; )*0 0/nvcqe e movable mirror of an interferometer. When the micrometer is tightened down on a thin metal foil, the net number of bright fringes that move, co8t0xf.cvye(o qdl *ed;v nu0x)zq/z 2mpared 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 mirrorbbny. qby/+(p,om1 ( rb6z4h 6gjb rpl $M_1$ 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 throug1s :sjtboixdi )(:/pqtl4 px )h 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 wavelength of 610 nm. Calculate the ) ) dp ( :/:josit41pilxxtbqsindex of refraction of the gas, assuming that the interferometer is in vacuum. $n_{gas}$

  

  Two polarizers are oriented at lnp.lzt( vid6y /h(-v 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–glase32f, q pht(g1k/vjups $(n=1.52)$ surface? $\theta_{p}$    $^{\circ}\,$

  What is Brewster’s angle for a1madqrs b71r2i w9h6v diamond submerged in water if the light is hitting1v 6r rq71ms2whdiab9 the diamond $(n=2.42)$ while traveling in the water? $\theta_{p}$    $^{\circ}\,$

  Two Polaroids are aligned so that the light passing through them iskm czm(o y:o;4+kin 3r a maximum. At what angle should one of them be placed so that the intensity is subsecm :nz r+3(ykmi;oo4k quently reduced by half?    $^{\circ}\,$

  At what angle should the axes of two Polaroids be ucbv6z 7x rb*2placed so as to reduce the intensity of the incidenzbx 6ru2 b*cv7t unpolarized light to
(a) $\frac{1}{3}$ ,    $^{\circ}\,$
(b) $\frac{1}{10}$ ?    $^{\circ}\,$

  Two polarizers are orient+x pk7i(:tuj(x6fr y ged 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 38/ga+hw-ks c m: .iv.nn.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;d d;ljl 98p:a7h htylater for light coming from beneath the surface? Compare to the angle7hall l9;j; :8hpdtyd for total 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 throudh9 zw oo))lk+gh five successive Polaroid sheets, each of whose axis makes aod zk)lo+ 9)hw 45$^{\circ}\,$ angle with the previous one. What is the intensity of the transmitted beam?    $I_0$

  Light of wavelength w(m wp d+ntq)-$ 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 w2;*jqf 4zhs )xnrga7/9twqw gaves reflecting from mountains or airplanes can interfere with the direct signal fr*wj qgx4h gtaf)q9r72zn w/;som 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 7ejegaakj8v g8j-3x 98a8egvj3gxk ja7e j-9$ 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 ppncp5fck * 2b7asses through two narrow slits 0.60 mm apart. The screen is 1.70 m away. A second source of unknown wavelength producecpb fcnp*752ks 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 bro-f.36;vzcj59f ev p abxnvzc ijd. d/-adcasts 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 and6v i5 j.-vf . c9xvd n/fp3zdjace-;zb 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 q7rrv mrhqvl*fp9/ mn(.)d 5v m wide, and blows a whistle of frequency 750 Hz. Ignoring reflections, estimate at what angle(s) it is not possible to hear the whistle clearly on (r9 pr/v. 5lmmn) r7q*fvqdhv the playground outside the doorway.    $^{\circ}\,$ either side of the normal.

If parallel light falls on a single slit o -*8)ui9ywldltu q4*3nw 7n6rz dliz.uhc6rsf 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 acrossn4ltpc f4n; ,f them. When normally incident 460-nm light is reflected from the wing, the wing a;f 4nc ,ntlf4pppears bright when viewed at an angle of 51$^{\circ}\,$. How far apart are the lines?    nm

  How many lines per centimeter must a gratif7 bd6wxo1 b,6t0m 2irv3harh:wq/ cqng have if there is to be no second-order spectrum for any visible wavecdowr 6rwtx ,h7bq h36 i:2vfmb/1q0alength?   $ lines/cm$

Show that the second- and third-order r; b4po7wvdg3 spectra of white light produced by a diffraction grating always overlap. What wavelengths overlap eb3p7 ;rd vw4ogxactly?

  When yellow sodium l hk/96 ef8 duqqqs5*ft (grwz+ight, $\lambda\;=\;$ 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 grad0b3te3 vkeqr./uv 6kting with and the pattern is viewed on a screen 2.5 m from the grating. The incident light beam consists of two wavelengue v0qe63tvkd rk/b 3.ths, $\lambda_1\;=\; 4.6\times10^{ -7}\;m$ 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 cleacx cbd, :(5 gw1nwuw-sr material if a minimum of 150 nm thickness of it, when laid on glass, is needed to reduce reflection to nearly zero when light of- gbs,n dc cu:ww1w5x( 600 nm is incident normally upon it? Do you have a choice for an answer?

  Monochromatic light of 1do* bwmb8ztx8ik (/hw mk05 xvariable wavelength is incident normally on a thin sheet of plastx(*8xk/ d ozbw15 0 kmi8tbwmhic film in air. 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 thic1qrv c/t:wbr-20exhj kness 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 air layer between two flat oz5ofq o y9l-r ;kgg-8ghfpd( pb5)itqe 6 ;(nglass surfaces if the glass is to appear dark when 640-nm light is incident lf(5k 5-gfbo; qegyi;hq-pzor p)96nd8o g( t normally?    nm
What if the glass is to appear bright?    nm

Suppose you viewed the light transmitted througe ; z:qcl7q,lsh a thin film layered on a flat piece of glass. Draw a diagram, similar to Fig. 24zq cls: 7qe;l,–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 Sun wh oufx -biaig3a;-/mfoa 1 l71yen light reflecting off a smooth lake is polarized mo -iy71 lo/1;aax 3abfgf-uimost strongly?    $^{\circ}\,$

  At what angle should the axes of two Pol qu1oye gsl1 3 g tb73-rusdn-.(;zyzxaroids be placed so as to reduce the intensity of urq3gxn.zyog1 t se1dy7 l--;ub 3s(zthe 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 b,mw.. usvqgcr58(9 mbr. dn rsheets whose transmission axes are at right angles. A third polarizer is plac.,mnrb. 5dgsw v.u rcq8 rm9b(ed 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 )yt,8rcnh c6o their 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 the Moon.ghy0t8e (or qc yuy64, which is approximately 380,000 km from the Earth. Assume the laser emits waves of wavelength 630 nm (the red light of a He-Ne laser). Estimate the width of ecty4u8hg ryy(o0 .q 6the beam when it reaches the Moon.    km

  A series of polarizers are each plac k8rcc zs2sqv 890g0nted 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 ppzfje-xabc*t 6wdcd31ixqn /55* +g(xr .c b$(n=1.34)$ 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-M,dpg jml+0 r0mHz radio waves in phase with each other. They are located at pointsj mdr0, ml+0gp $S_1$ 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 ua. o5st75x jajfvvnmz7 b(72wavelengths, 420 nm and 650 nm, enters a silicate flint glass equilateral prism (Fig. 24n z5vmsfj2x7tb . a7vu57jo(a–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/ guwm n51oivbp0 n/g: lens 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