Why is the depth of field greater, and the image sharper, when a camerzuwgeccz..w jh(q(bo 6*pt72a lens is “stopped down” to a larger f-number? Ignore diffractqc7zj..u*w e(o zp 6htwb2gc (ion.

Describe how diffraction affects the stqc p)*7 m2 wtpdgvjs-w2a(k4 batement that the depth of field is greater and the image sharper when a camera lens is “stopped down” to a larger f-numgwp (t74pb)vks*jcqmaw2 d- 2ber.

Why must a camera lens be moved faz (vfr1.qgfyw 8h*s a +f .b79*dni/mvnz8vqurther from the film to focus on a closer objec* was 1z9vu8 m qiv h+nnbqv*fz8d./yrfg.(f7t?

Why are bifocals needed mainly by older persons and not general0ip-*iy 3*4fhap xltbnt id 7h j0y,x1ly by younger peolpjyptx1*hfih0 7inb a,*y0 x3d4t - iple?

  Will a nearsighted pers.h7r6bpgdhp,w x 9 7qd -w(cbvaeqh3nti7+b /on who wears corrective lenses in her glasses be able to see clearly under/7bqgdhn 97d t+h6i 7 x(wpc.a qbwe-vbph ,3rwater when wearing those glasses?  ----待选择----yesno Use a diagram to show why or why not.

You can tell whether a person is nearsighted or farsighted by looking 9 -wo* *kannhryem7 4tat the width of the face through their glasses. If the person’7k-mahw 9ort e **ny4ns face appears narrower through the glasses (Fig. Below), is the person farsighted or nearsighted?

In attempting to discern distant details, people will sometim3m otxe r;-iyvud/( z./+ pslwes squint. Why does t(3xzls+mp/o rew.-;v/ dyu tihis help?

Is the image formed on the retina of the human eye upright or inverted? Divcpnu r;42j2ygb 0b-gsat4:escuss the iu2b4a:e b4vg;-ny p2 0crstj gmplications of this for our perception of objects.

The human eye is much*kx4zqj4, rmg0psz c- like a camera — yet, when a camera shutter is left open and the camera is moved, the image will be blurred; but wj zk0zc- mxr4q*4p, sghen you move your head with your eyes open, you still see clearly. Explain.

  Reading glasses use idn+ 4rel.h aetc-wy)x3) yt8converging lenses. A simple magnifier is also a converging lens. Are reading ex dni a 3tc)tye+l-.hy4wr)8 glasses therefore magnifiers? ----待选择----yesno  Discuss the similarities and differences between converging lenses as used for these two different purposes.

Inexpensive microscopes for childbp6k2bqubv3qw1.6: p dw o/xpren’s use usually produce images that are colored at the w1bv k6pqq./6w2x3pobbp: udedges. Why?

Spherical aberration in a thin lens is minimized if rays are bent equa)4e i nfbqemzj52y -o0lly by the two surfaces. If a plano-e mez )yonb0j2fq i54convex lens is used to form a real image of an object at infinity, which surface should face the object? Use ray diagrams to show why.

Which aberrations present i/1(gyzcbzal 6k4 2u hkn a simple lens are not present (or are greatly reduced) in the zk2 buy/z6 lgk1h (4cahuman eye?

Explain why chromatic aberration +) obdttg3): y tcpo0roccurs for thin lenses but not for mirrors.

  By what factor can you improve resolution, other us.zjx z4r0b78z)wr zthings being equal, if you use blue lightz wzbz4870)xur .zjsr ($\lambda=450mm$) rather than red (700 $nm$)?  

Give at least two advantages for /qu2hli5*hf0ca: umk the use of large reflecting mirrors in astronomical telesm k5hci:0a*uf/lqu 2hcopes.

Which color of visiblo9 xae o,2labwyc ,o;8e light would give the best resolution in a microscope? Explel,2b; ax8o oo9yc wa,ain.

  Atoms have diameters of ogjtavtf6t5qu n8 -jii4j.2zvmg79k 5;1suaabout $10^{-8}\,$cm$. Can visible light be used to “see” an atom? ----待选择----yesno  Explain.

  A 55-mm-focal-length lens has f-stops rangi33ol(lth fw: vng 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 lens has a 1486,r2e w2i7tzby kj fi-$cm$ focal length and a lens diameter of 6.0 $cm$. What is its $f$-number? $f$/  

  A light meter reports that a cam; kizlc:y;.i zera setting of $\frac{1}{250}\,s$ 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 tak,q zu 3qv;z;hqen 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 that kd wt2.(w cc9jit is 200.0 mm to 206.0 mm from the film. For what range ofjd.k cw( tcw92 object distances can it be adjusted?    $\mathrm{m}\leq d_{\circ}\leq\infty$

  A nature photographer wishes to photograph ap3leu :+r:g:l5e ri di 28-mtall tree from a distance of 58 m. What focal-length lens should be used if +erlr3:p i5:g:le uid the image is to fill the 24-mm height of the film?    mm

A “pinhole” camera uses a tiny pinhole instead of a lenb6z(c5nqa1g wh 6f3kts. Show, using ray diagrams, how reasonably sharp images can be formed using such a pinhole camera. In particular, consider two pfgkzctnbw56(a q6 3 1hoint 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 ek0p+q:d a 9pj3o :kmbtxposure 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 2bjch- ro3 4f(*wab:oe jz08.sxotc-p.0 $cm$ 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 wo-njd*zx li9(0p /qah*ys u(u bre contact lenses corrected for the far poz uxd s/n0 y(*qp-lu(bhji9*a int $(=\,\infty)$ 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 personhk6 vj09o 2rh 55ijbgp whose 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 point of 1r+fpce.it dqgn ( ; 8:ncjxl/.4 $cm$. 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 holding a book at arm’s length, a distancv rh -jn6tb0v6e 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 igkkfj 0qj.bopcc0. ;is(;x0te / zoj5s corrected by 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 clearl s1:52r*iwn d9aqkkze1rcn b3 y only if they are between 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 rqb 10z2ofp)d is the nearsighted 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 focal gmy: tz7kb,.p f06di blength 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 of the eye–lens system when viewing yjwam)6yeif*ed2.t 7o.3 wzu 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 and far poinyuijaw, /8 8b1x 9unvgts 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 used with a relaxed ej/v5*t59j 9e 8st xwd1olqa88w v wfnjye if its focal length isdn81/5a8x8tw9w5o wv q sjj9j tefvl * 12 $cm$? =    $\times$

  What is the focal length of a magnifying a,6d nuxv2l 8hglass of $3.5\times$ magnification for a relaxed normal eye?    cm

  A magnifier is rated ath)4mi 7dsy tqr diz1yn14j m*rjxg35r4e5k6b $2.5\times$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 using a 94xismx+n1 j0xsxf6dn*2 j9ens(i* nk .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 beetld g8hnn/g 7 uwwjr6mv))h8 mp2+ly r1ce is viewed 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 placed -g6a qto(v *kc:nlwn75.55 $cm$ from a $+6.00-$cm$-focal-length$ lens. Calculate
(a) the position of the image,    cm
(b) the angular magnification. =    $\times$

  A magnifying glass w4c o5h.f*y5 da la9ywnith a focal length 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 atqnbn6j3;x(voy a0czhznray 1 71cm1 4 $3.0\times$ 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 astronomica+k97vwgiuj2d l telescope whose objective lens has a fo+i7vkd29jwu gcal length 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 magnification of an as x9jlp(.n9qk)-1-yd2 bxf ihtyh rf0j tronomical 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 objective with focal length 8j*vde 65lef,/kd7im ru;b1j e5 $cm$ and a $+35-D$ eyepiece. What is the total magnification? =    $\times$

  An astronomical telescope has itwbo)3,ehoy.eg z 0ux-s 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 adjusted for a relaxedvd 0ky;d74 f7ul /gpzx 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 powerhk8ykerpmkbq,*m pfi /g9k99 z9* 7 br of an astronomical telescope using a reflecting mirror whose radius of curvature is 6.09mm pe9/ 8bzkqk *kb9y79rk pf gihr,* $m$ and an eyepiece whose focal length is 3.2 $cm$? =    $\times$

  The Moon’s image appeaokqzx. s 5/8q4:r fkmdrs 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 miwtep:*c 7 r tk7+lsyexgf+*4 for its objective re+k+: ity47tgw7cxslpe* *f mirror 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 an eyep-x5)oapi x .fkiece 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 1f0ewbhvv5o)/ weqn +;2.0$times$ 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 1.8vka4+5 hv t5 ;ub75r2t,tc) ieoqqqq f-$cm$-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 27cyicg : tn7p-m*wgr image is located 25 $cm$ from the eyepiece (near point of a normal eye). $d_{oo}$ =    cm   $times$

  The eyepiece of a compob :mswm :*rt:dc(-cgg ti2td+h7 l;gm und microscope 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 t2-*c*gqq hpy cwo very thin lenses, placed in contact, that have focal lengths ofc*yphc q2 g*q- $f_1=-28\mathrm{~cm}$ 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. A p56rss3v .fvs1xi d.e planoconvex lens of index of refraction 1.50 and radius of vv fpexs1s 35d i.rs6.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 (degrees) set by diffraction for the 100-inw0ujzxoh)w358wa1 fq . (2x0 oqhzaw1uf 8j w3)5w54-$cm$ mirror diameter) Mt. Wilson telescope ($\lambda=550\mathrm{~nm}$)?   $ \times10^{ -5}\;^{\circ}$

  Suppose that you wish to construct a telescope that can resolve fotbs q: e;f*:deatures 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 foca6*7bmxsq mmxg *;5b bfl length of 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 barely resolved by 8ji vp5,( enavip6v,ia 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 headlights 2dl jyw.p-)b3t .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 byv)uch t y:s q xu1k4q;:5q+zqu about $400\times10^6\mathrm{~m.}$ 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 faac hn4 ubvs1.+s7/abf ll on a crystal whose atoms, lying in planes, are sps bshb 1na+.a7 4vuf/caced 0.280 $nm$ 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 directed at an unk0wkza6u9tor; 1v/g f wnown crystal. The second diffraction maximum is record ugaw 6 v;1zrtf/90kwoed 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 diffraction u* /.r vu +jdkh/n(d tno(whwj7*.iweis 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 the X-ray beam consisv1ubql l4ysc.:gq.*lr7. zn gts of parallel rays. What would be thlb.1lv 7gl qz:u.ycg*ns4rq. e magnification of the image? a the magnification is   
(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 midday, and the sunlit.6 jx p71lglrght got more intense, a photographer notejg6.rxl t1l7pd that, 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 infinlzw2 uqqsz9yblu)r.f:,t 2 1tity), the magnification of a camera lens is proportional to rqyt)u.z2z wlu,921s b: fqltits focal length.

  For a camera equipped with ab;ha; *s -5t + y8d 7peuyknyisw:j*fk 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 n/(a,t hwd :62)1 d-irvunoa* dtvqkgright eye only when objects 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 point of 15 pa*yg69bhm9 pt* paz ,$cm$. 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 apw 6 -z,uy0apfr/k- ma $+4.0-D$ lens used as a magnifier? Assume a relaxed normal eye. $M$ =    $\times$

  A physicist lost in the mountainso8i8n6xe md 2o ss/b53sk trx. tries to make a telescope using the lenses from his reading glassee.m 2 xr3n sdto8b8x s/6siok5s. They have powers 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 us pju ja1kp8-3c6 ,rpym9 ptr3pes $+2.5-diopter$ 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 extremm qs:h) qso)vi) p2vr3ely high 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 must beh01b y2:ufrn r+yhji - increased because of the increased distance of the lens from thry ur - 2+yh0b:nhfj1ie 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 and o6 r08tm9wn umthe 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 b8m.: p*a m7 vb/f9 qthpz:hadof 2.4 m, is viewing the Moon. Estimate the minimum distance between two objects on the Moon that the Hubble can distinguish. Consider diffraction of light of wavelength 550 nm. Assume the Htz:9. *av/fbbh pq d:ahmm7p8ubble is near the Earth.    m

  Two converging lenses, one withcl1z 2isi8sk 24gm)sv $f=4.0\mathrm{~cm}$ 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. I)+p)* z 2nceaps th -lm:zkv-jf the two lenses 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 satellite wswc6-zzsd7*a/ 8tqrs4o 6if to photograph license plate numbers. Assuming it is necessary to resolve fs-* wq/t8dos iwzs46r 7ca6 zpoints 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 s*cr8 afzzu1 x(urface 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