An
upright object is placed a distance in front of a converging lens
equal to twice the focal length
|
Solution: Click For PDF Version We will solve this problem in three steps. We first find the image of a candle placed at a distance
from a converging lens of focal length
 .
Let the image be formed at a distance
from the lens. We use the thin lens equation for finding
.
We have
The first
image formed by the converging lens will be real and inverted and
will be at a distance
This image
will therefore be real and it will be at a distance
As we are
looking at the final image through the lens, we next calculate the
image formed by the converging lens of the image formed by the
concave mirror. As the object is real, its distance from the
converging lens will be
The final
image will be at a distance
Therefore, the final image of the candle as seen through the lens will be real and at the location of the candle. We now work out the lateral magnification. It will be
Therefore, we find that the final image will be at the location of the candle, unchanged in size but will be inverted. |
separated from the lens by a distance
;
see the figure. (a) We
have to find the location, nature, and
relative size of the image, as
seen by an eye looking toward the image through the lens.
.
We now use the spherical mirror formula for locating the image
formed by the concave mirror of the real image of the candle formed
by the converging lens. We have
.
from the converging lens.
