Bukhovtsev-et-al-Problems-in-Elementary-Physics

GEOMETRICAL OPTICS
403
~--Z5cm-"
------:~f2
_-------
I
I
-------~
I
Fig. 525
732. Image A' B' of the object in the spherical mirror will be at a distance
b l (Fig. 526) from the mirror determined by the formula of the mirror
1 2
at -b I
=R
Hence, b i =8 em. Distance AA' is 48 ern. Therefore, the plate should be placed
at a distance of 24 cm from object AB.
733. Two cases are possible:
(a) The mirror is at a distance of d = f+R from the lens. The path of the
beam parallel to the optical axis of the system and the image of object AB
are illustrated in Fig. 527. Image A'B' (direct and real) is obtained to full
seaIe with the object in any position.
(b) The mirror is at a distance of d==f=R from the lens (Fig. 528).
The image of object A' B', also full-scale, will be inversed and virtual
with the .object in any position.
734. The path of the rays in this optical system is shown in Fig. 529.
When the second lens is absent, the first one produces image A' H' that is at
a distance of b i = 60 em from the lens. This distance can be found from the
formula of the lens
~+.!.=.!.
at b I f1
Image A' B' is virtual with respect to
the second lens. Therefore,
_-.!..+J.=..!.
a 2 b2 f2
Fig. 526
where a 2 = b t - d= 30 em.
Hence, b 2=7.5 em.
735. It follows from the solution of the
previous problem that in the case of two
convergent lenses at a distance d from each
other the following equation is true
1.- +J.. =~+J.. +d (al- '1) (12 -b2)
at b 2 II 12 alb2f l f 2
26 *