Page 420 - Schaum's Outline of Theory and Problems of Applied Physics

CHAP. 32] LENSES 405

Since the angular magnification of the telescope is 40 and m ang = θ /θ, θ = m ang θ,so

L
= (40)(0.033 rad) = 1.3 rad
25 cm
L = (1.3 rad)(25 cm) = 33 cm
The boat seems to be 33 cm long and to be located 25 cm from the viewer’s eye.

Multiple-Choice Questions

32.1. The image of a real object farther from a converging lens than f is always which one or more of the following?

(a) smaller than the object (c) virtual
(b) the same size as the object (d) inverted

32.2. The image of a real object closer to a converging lens than f is always which one or more of the following?
(a) smaller than the object (c) virtual
(b) the same size as the object (d) inverted

32.3. The image of a real object the distance f from a converging lens
(a) does not exist (c) is real, inverted, and larger than the object
(b) is virtual, erect, and larger than the object (d) is real, inverted, and the same size as the object

32.4. A real image formed by a lens is always which one or more of the following?
(a) smaller than the object (c) erect
(b) larger than the object (d) inverted
32.5. The image formed by a diverging lens of a real object is never which one or more of the following?
(a) real (c) erect
(b) virtual (d) smaller than the object

32.6. A negative magnification corresponds to an image that is
(a) erect (c) larger than the object
(b) inverted (d) smaller than the object

32.7. A negative image distance corresponds to an image that is
(a) erect (c) real
(b) inverted (d) virtual

32.8. The object distance of a converging lens of focal length f used as a magnifying glass must be
(a) less than f (c) between f and 2 f
(b) f (d) more than 2 f
32.9. The image distance of an object located 12 cm from a converging lens of focal length 16 cm is

(a) −4cm (c) +4cm
(b) −48 cm (d) +48 cm

32.10. The image distance of an object located 16 cm from a converging lens of focal length 12 cm is
(a) −4cm (c) +4cm
(b) −48 cm (d) +48 cm