Why is the depth of field greater, and the ima nwf*: npx;4(kru(c fage sharper, when a camera lens is “stopped down” to a larger f-number? Ignore diffraa(4n r p fc;kw(f*nu:xction.

Describe how diffraction affects the statement that the (xiv+/9vqw;w bceh lqzg)k 7)depth of field is greater a7 w lv(qkbg 9z/q;ei) hxc)+vwnd the image sharper when a camera lens is “stopped down” to a larger f-number.

Why must a camera lens be moved far7ovdk4ppu,d ow5k8p -ther from the film to focus on a closer objecpowup pod7 4k8,vk5-dt?

Why are bifocals needed mainly by older persons and not generally by youngs t (96; pmyyi*j,ybr:iay)qy q(*vb ger peopleyby:sbt9(yvq(q,y r *mgjy6i *)p a i;?

  Will a nearsighted person who wears corrective lenses in her glasses be able dlf90,0vum r2cn fa; rto see clearly undefald nf09uv , mrcr0;2rwater when wearing those glasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether a pem . x*wm8k8 5pnoxwc1mrson is nearsighted or farsighted by looking at the width of the face through their g w c5pw8nk8xo.mm*xm 1lasses. If the person’s face appears narrower through the glasses (Fig. Below), is the person farsighted or nearsighted?

In attempting to discern distant details, people will sometimes squint.e.6ya4we)8t i smm5 lajq.ww6 Why does thi6j6yla8ws )a5..4eqww it mmes help?

Is the image formed on the retina of the human eye upright or inverted? Discusslhgr e5wy1 ,6xg.xrf ( kr4d7i the implications of1 e(57x6fl 4ydrg .khxi rw,gr this for our perception of objects.

The human eye is much like a camera — yet, when a cauqb1r l92k p)fmera shutter is left open and the 9frubk 1)lpq2 camera is moved, the image will be blurred; but when you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use converging lenses. A simple mayohx6 ss74st.gra /h8gnifier is also a converging lens. Are reading glasses therefore magnifiers7g4 /8h.yoahr s6ssxt? ----待选择----yesno  Discuss the similarities and differences between converging lenses as used for these two different purposes.

Inexpensive microscopes for children’s use usually produce images thay:jkg,rc f7 cls4a +.uu +ct/bt are colored at th7,cjlc+gt/ kuba.yf : u4sc +re edges. Why?

Spherical aberration in a thin lens is minimized if rays are bent equally 1c5 ebtv:x:su25nsnsnsd6v6 by the two surfaces. If a planoconvex lens is used to form a real image of an object at infinity, which surface n s 5:vss5dscb2n t neu:xv166should face the object? Use ray diagrams to show why.

Which aberrations present in a simple lens ajv:umo343zr zkv 9 lp;wq na5ygl/f:+ re not present (or are greatly reduced) in th mrqn: v:aklov5 349 gyfluw;/pzzj 3+e human eye?

Explain why chromatic aberratiop)q66ne : e h*roa9gzbn occurs for thin lenses but not for mirrors.

  By what factor can you improve resolution,z 0 1jrihv( g+9tau)fl other things being equal, if you use blua1lg tr(f 0+uzij) vh9e light ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages for the *kv ro)elx/i+l v87geuse of large reflecting mirrors in astronomicali/xl)oeek*lv+ 7rg v 8 telescopes.

Which color of visible light would give the best resolution i th3d v5pmt7rfx-7/xjn a microscope? Explaj7fhp xm3rvt 5xt- /d7in.

  Atoms have diameters of nu.d1+psx)o/*b c jx ug6 v:xnc3)imiabout $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stops bq(;9jw9x idm kj;j)a ranging from $f/1.4$ to $f/22$. What is the corresponding range of lens diaphragm diameters?    $\mathrm{mm}\leq D\leq$    $\mathrm{mm}$

  A television camera lenxk9 1qs 7eg8nos has a 14-$cm$ focal length and a lens diameter of 6.0 $cm$. What is its $f$-number? $f$/  

  A light meter reports that a camera setting zxoam. ,+ qo-nof $\frac{1}{250}\,s$ at $f/5.6$ will give a correct exposure. But the photographer wishes to use $f/11$ to increase the depth of field. What should the shutter speed be?$t_2$ = 1/   s

  A properly exposed photograph is oe 7i772qc, dp7lhjt rtaken at $f/16$ and $\frac{1}{60}\,s$ What lens opening would be required if the shutter speed were $\frac{1}{1000}\,s$? $f$/  

  If an $f$ = 135-mm telephoto lens is designed to cover object distances from 1.2 m to $\infty $, over what distance must the lens move relative to the plane of the film?    mm

  A 200-mm-focal-length lens can be adjusted so thaf/ime; ) 3deibt it is 200.0 mm to 206.0 mm from the film. For what rangefemd)bi 3/ei ; of object distances can it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photogrlnxajm9wt, u fjr)a 3hp/9k:.l ,o-ipaph a 28-mtall tree from a distance of 58 m.pu9 :malor/j. fijnhl, k,a39 -tx)pw What focal-length lens should be used if the image is to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiny pint m 5l.pbr 5h/,3nknlzhole instead of a lens. Show, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particular, co/,pk5lml.z 53nbht rn nsider two point objects 2.0 $cm$ apart that are 1.0 m from a 1.0-mm-diameter pinhole. Show that on a piece of film 7.0 $cm$ behind the pinhole the two objects produce two separate circles that do not overlap.

  Suppose that a correct exqzz* xdhe ;w,;posure is $\frac{1}{250}\,s$ at $f/11$ Under the same conditions, what exposure time would be needed for a pinhole camera (Problem 8) if the pinhole diameter is 1.0 mm and the film is 7.0 $cm$ from the hole? $t_2$ = 1/   s

  A human eyeball is about 2.g;z 9,edzx- -l at9grjql4ly60 $cm$ long, and the pupil has a maximum diameter of about 8.0 mm. What is the “speed” of this lens? $ f-stop$ = f/  

  If the nearsighted person in Example 25–6 wg cplam*8-g ;o t2gxf9ore contact lenses corrected for the falmg g-2 x9;*cgapt8o fr point $(=\,\infty)$ show that the near point would be 41 $cm$. (Would glasses be better in this case?) glasses would be  ----待选择----betterworse 

  Reading glasses of what power are needed for a person whos j4fse5o pn,5de near point is 115 $cm$, so that he can read a computer screen at 55 $cm$? Assume a lens–eye distance of 1.8 $cm$.+    D

  A person has a far pot ubhg tnto-3:(9c9zgint of 14 $cm$. What power glasses would correct this vision if the glasses were placed 2.0 $cm$ from the eye?    What power contact lenses, placed on the eye, would the person need?   

  A person struggles to read by hol;;yt:9bu ffe oding a book at arm’s length, a distance of 45 $cm$ away (= near point). What power of reading glasses should be prescribed for him, assuming they will be placed 2.0 $cm$ from the eye and he wants to read at the normal near point of 25 $cm$? +    D

  A person’s left eye is corrected e: gt85 yy 5holh)j3qtby a $-3.50-diopter$ lens, 2.0 $cm$ from the eye.
(a) Is this person’s left eye near- or farsighted?  ----待选择----nearsightedfarsighted 
(b) What is this eye’s far point without glasses?    cm

  A person’s right eye can see objects clearly only if they are betmeu 7dxr z19d*ween 25 $cm$ and 75 $cm$ away.
(a) What power of contact lens is required so that objects far away are sharp? -    D
(b) What will be the near point with the lens in place?    cm

  About how much longer is the nearsightd1gdb)4. yjbqd-px-k6e,z ir8fd;y oed eye in Example 25–6 than the 2.0 $cm$ of a normal eye?    cm

  One lens of a nearsighted person’s eyeglasses has a)zrdcd u e+gx67b kr7e)*q,ka focal length of $-22.0 \, cm$ and the lens is 1.8 $cm$ from the eye. If the person switches to contact lenses that are placed directly on the eye, what should be the focal length of the corresponding contact lens?    cm

  What is the focal length 0 +j,wrc/ wmg9gjp76 n 0cyu7i,zwdt oof the eye–lens system when viewing an object
(a) at infinity,    cm
(b) 33 $cm$ from the eye? Assume that the lens–retina distance is 2.0 $cm$.   cm

  A nearsighted person has near aezn0f5lx3o s, nd far points of 10.0 and 20.0 $cm$, respectively. If she puts on contact lenses with power $P\,=\,-4.00D$, what are her new near and far points?
near point    cm
far point    cm

  What is the magnification of a lens usedi +h ta-jkpypvc49l vumv*7,gn/* 8 vy with a relaxed eye if its focal length iskjagyv4+8nl9,pvi v/m*cu7 vtp yh*- 12 $cm$? =    $\times$

  What is the focal length of akkf9u 9227m yw2bepf k magnifying glass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is ratedw7cgr-i8rhypg rsz a 0yb854:f2 -sdz at $2.5\times$for a normal eye focusing on an image at the near point.
(a) What is its focal length?    cm
(b) What is its focal length if the $2.5\times$ refers to a relaxed eye?    cm

  Sherlock Holmes is using7kot mvd19vy3s- eqdr8i)f7rg9w. em a 9.00-$cm$-focal-length lens as his magnifying glass. To obtain maximum magnification, where must the object be placed (assume a normal eye), and what will be the magnification?
$d_o$ =    cm from the lens
M =    $\times$

  A 3.30-mm-wide beetle is v oii- ugso :k9n.(f6hpxn4 mn0iewed with a 9.50-$cm$-focal-length lens. A normal eye views the image at its near point. Calculate
(a) the angular magnification, =    $\times$
(b) the width of the image,    mm
(c) the object distance from the lens.    cm from the lens

  A small insect is placq uoqjj5(io7i3g.o - ded 5.55 $cm$ from a $+6.00-$cm$-focal-length$ lens. Calculate
(a) the position of the image,    cm
(b) the angular magnification. =    $\times$

  A magnifying glass with a focal lencna) 1kl-sgu) twp( a4gth of 8.5 $cm$ is used to read print placed at a distance of 7.5 $cm$. Calculate
(a) the position of the image;    cm
(b) the angular magnification. =    $\times$

  A magnifying glass is rated at z up-9/3 )iix2lhf kzg$3.0\times$ for a normal eye that is relaxed. What would be the magnification of this lens for a relaxed eye whose near point is
(a) 55 $cm$, =    $\times$
(b) 16 $cm$? Explain the differences. =    $\times$

  What is the magnification of an astronomi;/b5wyw g-bqtcal telescope whose objective lens has a focal leb/-wy5qgt; w bngth of 76 $cm$ and whose eyepiece has a focal length of 2.8 $cm$? What is the overall length of the telescope when adjusted for a relaxed eye?
M =    $\times$
L =    $\times$

  The overall magnifica1wsd+l:udkrceefrw22 dq3-5g4e8 jf tion of an astronomical telescope is desired to be 25$\times$. If an objective of 78$-cm$ focal length is used,
what must be the focal length of the eyepiece? $f_e$ =    cm
What is the overall length of the telescope when adjusted for use by the relaxed eye? L =    cm

  An 8.0$\times$ binocular has 2.8$-$cm$-focal-length$ eyepieces. What is the focal length of the objective lenses?    cm

  An astronomical telescope has an :pr ,(zqhe (yw3vy i9yobjective with focal length 85 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telesc4l3v iamivpzb2ts.d v9 p29 +rope has its two lenses spaced 75.2 $cm$ apart. If the objective lens has a focal length of 74.5 $cm$, what is the magnification of this telescope? Assume a relaxed eye. =    $\times$

  A Galilean telescope adjust 7igr tk2 ce3xo:st(+ced for a relaxed eye is 32.8 $cm$ long. If the objective lens has a focal length of 36.0 $cm$, what is the magnification? =    $\times$

  What is the magnifying power of an j *lqddq-46g yastronomical telescope using a reflecting mirror whose radius of q6 4-dyjqlg*d curvature is 6.0 $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appearb98wkd .sw )n0g*ls2;qt xd2p ) uimzws to be magnified 120$\times$ by a reflecting astronomical telescope with an eyepiece having a focal length of 3.2 $cm$. What are the focal length and radius of curvature of the main (objective) mirror? M =    m r =    m

  A 170$\times$ astronomical telescope is adjusted for a relaxed eye when the two lenses are 1.25 m apart. What is the focal length of each lens?
$f_e$ =    mm
$f_o$ =    m

  A reflecting telescope (Fig. Below) has a radius of curvature of 3.0 m3:akk +*yx;fuum ildp dfdh4 ,) b4 5wmcy2yq8 for its objective ,u l kyqy ;c)ka u4fd8dpyx5wmfh 4:*bim+2d3mirror and a radius of curvature of $-1.50m$ for its eyepiece mirror. If the distance between the two mirrors is 0.90 m, how far in front of the eyepiece should you place the photographic film to record the image of a star? $d_{2i}$ =    m

  A microscope uses an9dmtph4+0 wilg.dg.g eyepiece with a focal length of 1.40 $cm$. Using a normal eye with a final image at infinity, the tube length is 17.5 $cm$ and the focal length of the objective lens is 0.65 $cm$. What is the magnification of the microscope? =    $\times$

  A 620 $\times$ microscope uses a 0.40-$cm$-focal-length objective lens. If the tube length is 17.5 $cm$, what is the focal length of the eyepiece? Assume a normal eye and that the final image is at infinity. $f_e$ =    cm

  A 17-$cm$-long microscope has an eyepiece with a focal length of 2.5 $cm$ and an objective with a focal length of 0.28 $cm$. What is the approximate magnification?    $times$

  A microscope has a 1) i0sh+ tt0p6*wlcr6eld:cdl n9 s3qv2.0$times$ eyepiece and a 59.0$times$ objective lens 20.0 $cm$ apart. Calculate
(a) the total magnification,    $times$
(b) the focal length of each lens, $f_e$ =    cm $f_o$ =    cm
(c) where the object must be for a normal relaxed eye to see it in focus. $d_o$ =    cm

  A microscope has a 1.8q6hxf.:wvl9pjc ign v:kq ws 3 7,f6d/cc5;si-$cm$-focal-length eyepiece and a 0.80-$cm$ objective lens. Assuming a relaxed normal eye, calculate
(a) the position of the object if the distance between the lenses is 16.0 $cm$, $d_{oo}$ =    cm
(b) the total magnification.    $times$

  Repeat Problem 61 assuming that the final image is located 25h+d0t*f dxi .r $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compound microu f b5v7ixm2o.pwpw,0q7i 3 nbscope has a focal length of 2.70 $cm$, and the objective lens has $f=0.740\mathrm{~cm}$. If an object is placed 0.790 $cm$ from the objective lens, calculate
(a) the distance between the lenses when the microscope is adjusted for a relaxed eye, $l$ =    cm
(b) the total magnification.    $\times$

  An achromatic lens is made of two very thin lenses, placed in con movz/w,ezo. )tact, that have f /mo .),ezowvzocal lengths of $f_1=-28\mathrm{~cm}$ and $f_2=+23\mathrm{~$cm$}.$
(a) Is the combination converging or diverging?  ----待选择----convergingdiverging 
(b) What is the net focal length?    m

  Let’s examine spherical aberration in a particular situation.sd+*n e l/swj ,7hj fo cby.v3(8ppep-w xbs./ A planoconvex lens of index of.bp eps.7cl/djshwvn*js(be +fyo w,3/8px- refraction 1.50 and radius of curvature $R=12.0\mathrm{~$cm$}$ is shown in (Fig. Below). Consider an incoming ray parallel to the principal axis and a height h above it as shown. Determine the distance d, from the flat face of the lens, to where this ray crosses the principal axis if
(a) $h=1.0\mathrm{~$cm$},$ $d_1$ =    cm
(b) $h=6.0\mathrm{~$cm$},$ $d_2$ =    cm
(c) How far apart are these “focal points”? $\Delta d$ =    cm
(d) What is the radius of the “circle of least confusion” produced by the $h=6.0-\mathrm{~$cm$},$ ray at the “focal point” for $h=1.0\mathrm{~$cm$},$? r =    cm

  What is the angular resolution limit (degr 9e av28dzwxe8ees) set by diffraction for the 100-in. (2548xwa 9ved2ez8 -$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to construct a telescope that can resolve f,e.h:wh,gl+* bxtrjq-b i5rl eatures 7.0 $km$ across on the Moon, 384,000 $km$ away. You have a 2.0-$m$-focal-length objective lens whose diameter is 11.0 $cm$.
What focal-length eyepiece is needed if your eye can resolve objects 0.10 $mm$ apart at a distance of 25 $cm$? $f_e$ =    cm
What is the resolution limit (radians) set by the size of the objective lens (that is, by diffraction)?
Use $\lambda=550\mathrm{~nm.}$ $\theta$   $ \times10^{ -6}\;rad$

  The normal lens on a 35-mm camera has a focal length l1 ifal1vkp4;ode tq6 ,ul0-iof 50.0 $mm$. Its aperture diameter varies from a maximum of 25 $mm$ $(f/2)$ to a minimum of 3.0 mm $(f/16)$. Determine the resolution limit set by diffraction for $f/2$ and $f/16$. Specify as the number of lines per millimeter resolved on the film. Take $\lambda=550\mathrm{~nm.}$
For $\frac{f}{2}$ we have $\frac{1}{RP_2}$ =    lines/mm
For $\frac{f}{16}$ we have $\frac{1}{RP_2}$ =    lines/mm

  Two stars 15 light-years away are barelrxwqu4* vyo: me*z-v6. z;vfxy resolved by a 55-$cm$ (mirror diameter) telescope. How far apart are the stars? Assume $\lambda=550\mathrm{~nm.}$ and that the resolution is limited by diffraction.   $ \times10^{11 }\;m$

  (a) How far away can a human eye distinguish two car heasjqe6n hi mv )1q(+(ondlights 2.0 $m$ apart? Consider only diffraction effects and assume an eye pupil diameter of 5.0 $mm$ and a wavelength of 550 $nm$.
L =    km
(b) What is the minimum angular separation an eye could resolve when viewing two stars, considering only diffraction effects? In reality, it is about of arc. Why is it not equal to your answer in (b)? $\theta$ =    $\times 10^{-3}$ $^{\circ}$

  The Earth and Moon are separated by aba 5nj9bm9s c09*zlet8wd3;eakazm- f8e) gwpout $400\times10^6\mathrm{~m.}$ When Mars is $8\times10^{10}\mathrm{~m}$ from Earth, could a person standing on Mars resolve the Earth and its Moon as two separate objects without a telescope? Assume a pupil diameter of 5 $mm$ and $\lambda=550\mathrm{~nm}.$  ----待选择----yesno 

  X-rays of wavelength 0.133 nm fall on a crynk7gcyzg0r74e+ i 4ie stal whose atoms, lying in planes, are spaced 0ekg i7 4+ginr47y ezc0.280 $nm$ apart. At what angle \phi (relative to the surface, Fig. Below) must the X-rays be directed if the first diffraction maximum is to be observed? $\phi $ =    $^{\circ}\,$

  X-rays of wavelength 0.0973 nm are directer bxv f m))i77dxlm1*id at an unknown crystal. The second diffraction maximum is recorded xib x )mrv7d) mfi7l1*when the X-rays are directed at an angle of $\mathrm{23.4°}$ relative to the crystal surface. What is the spacing between crystal planes? d =    nm

  First-order Bragg diffu62m 2a wgl91srvm (kwraction is observed at $\mathrm{25.2°}$ related to the crystal surface, with spacing between atoms of 0.24 $nm$.
(a) At what angle will second order be observed? $\phi_2 $=    $^{\circ}\,$
(b) What is the wavelength of the X-rays? $\lambda $ =    nm

  (a) Suppose for a conventional X-ray image that th3i( )zkusm7 e.1wsy nf4gn4 lme X-ray beam consists of parallel rays. What would be the magnification of the image? a the magnification is l4e.w3 i kf( gmszunmn1s)4y7  
(b) Suppose, instead, the X-rays come from a point source (as in Fig. Below) that is 15 $cm$ in front of a human body 25 $cm$ thick, and the film is pressed against the person’s back. Determine and discuss the range of magnifications that results. $m_1$ =    the magnification is  

  Sam purchases $+3.50-diopter$ eyeglasses which correct his faulty vision to put his near point at 25 $cm$. (Assume he wears the lenses 2.0 $cm$ from his eyes.)
(a) Calculate the focal length of Sam’s glasses.    cm
(b) Calculate Sam’s near point without glasses. his near point is    cm
(c) Pam, who has normal eyes with near point at 25 $cm$, puts on Sam’s glasses. Calculate Pam’s near point with Sam’s glasses on.    cm from her eyes

  As early morning passed toward middayw b:+h*c bjxfg h+5i0q, and the sunlight got more intense, a photographer noted that,fwgbj+ b5x i0 q:hc*+h if she kept her shutter speed constant, she had to change the $f$-number from $f/5.6$ to $f/22$. By what factor had the sunlight intensity increased during that time? $I_2$ =    $I_1$

Show that for objects very far away (assume infinity), the magf xqtlc1c.c3 hybzm.f2;(/gcv tjv9(nification of a camera lens is proportional to its xc/hc3mqygtf; 2cf v1.b(z( 9vl ct.jfocal length.

  For a camera equipped with ajclegg id:46.9w2i*bdj kf4e la,,ibdt qc3 0 50-$mm$-focal-length lens, what is the object distance if the image height equals the object height? How far is the object from the film?
$d_o$ =    mm
d =    mm

  A woman can see clearly with her right eye only when objects t )ifhmf-.bv. are between 45 $cm$ and 155 $cm$ away. Prescription bifocals should have what powers so that she can see distant objects clearly (upper part) and be able to read a book 25 $cm$ away (lower part) with her right eye? Assume that the glasses will be 2.0 $cm$ from the eye.
$P_1$ =    D(upper part)
$P_2$ =    D(lower part)

  A child has a near poic1xwl .d4 u;r9xs-uul1 o* tpwy 4s3kbnt of 15 $cm$. What is the maximum magnification the child can obtain using an 8.0-$cm$-focal-length magnifier? What magnification can a normal eye obtain with the same lens? Which person sees more detail?
$M_1$ =    $\times$
$M_2$ =    $\times$

  What is the magnifying power of acpr p; ,k)7kv7/s1jti psf+o s $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mountains tries to make a telescope usingtbv-x) nfccw+ tq;:6c *awro 1 the lenses from his reading glasses. They have p6a)- rcx1 tfo+qwc *vnw;ct:bowers of $+2.0-D$ and $+4.0-D$, respectively.
(a) What maximum magnification telescope is possible? $M$ =    $\times$
(b) Which lens should be used as the eyepiece?    D

  A 50-year-old man uses *)1j4i baam vr$+2.5-diopter$ lenses to read a newspaper 25 $cm$ away. Ten years later, he must hold the paper 35 $cm$ away to see clearly with the same lenses. What power lenses does he need now in order to hold the paper 25 $cm$ away? (Distances are measured from the lens.) $P_2$ = +    D

  Spy planes fly at extremely higwwv t;i 4e1ipv/su:y5fuzsp.v*8 8 skh altitudes (25 $km$) to avoid interception. Their cameras are reportedly able to discern features as small as 5 $cm$. What must be the minimum aperture of the camera lens to afford this resolution? (Use $\lambda=550\mathrm{~nm}.$)D =    cm

When shooting pictures at very short distances, exposure times m t/:e ma6n)tqo.(h(hcx.ypuuust be increased because of the increased distance)etu. .xy /ut(cqa(nhho :pm6 of the lens from the film for a focused image.
(a) Show that when the object is so close to the camera that the image height equals the object height, the exposure time must be four times longer (or 2 f-stops) than when the object is a long distance away (say, $$\infty), given the same illumination and f-stop.
(b) Show that if $d_o$ is at least four or five times the focal length f of the lens, the exposure time is increased by less than half an f-stop relative to the same object being a great distance away.

  The objective lens andw d.e5 1vcx -vpozht++ the eyepiece of a telescope are spaced 85 $cm$ apart. If the eyepiece is $+23$ diopters, what is the total magnification of the telescope? $M$ =    $\times$

  The Hubble Space Telescope, with an objective diameter of 2.4 mo:s2t7 k/-n t zyee0h1k*qmqc, is viewing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguish. Considhe/n7 z:t o*-mkt 2q0sqyc ke1er diffraction of light of wavelength 550 nm. Assume the Hubble is near the Earth.    m

  Two converging lenses,/b*w2 qy.f 7d; ltep1ez rt/fs one with $f=4.0\mathrm{~cm}$ and the other with $f=44\mathrm{~cm}$ are made into a telescope.
(a) What are the length and magnification? Which lens should be the eyepiece?
The distance between the two lenses is   cm
M =    $\times $
f =    cm
(b) Assume these lenses are now combined to make a microscope; if the magnification needs to be $25\times,$ how long would the microscope be?    cm

  An astronomical telescope has a magnification of 8.0. If the two l6 n2uf6dyu4amjln9 l2 enses are 28 $cm$ apart, determine the focal length of each lens.
The focal length of the eyepiece lens is    cm
The focal length of the objective lens is    cm

  You want to design a spy satellitt+3xg1fb j i *u3k tgdty)o3 q2,3mtc:v y3yere to photograph license plate numbers. Assuming it is necessary to resolve poitjgibt odtu y3 y 3:)re3c1*tv,k332x+mg yqf nts separated by 5 $cm$ with 550-$nm$ light, and that the satellite orbits at a height of 130 $km$, what minimum lens aperture (diameter) is required? D =    m

  A Lucite planoconvex lens (Fig. Below) has one flat surfac+zvbjc2 p llyj*f;i 7.e and the other has $R=18.4\mathrm{~cm}.$ This lens 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 glass 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? $d_{i\,red}$ =    cm
$d_{i\,orange}$ =    cm