Question

When a pin of height 3 cm is fixed at 10 cm from a convex lens, the height of the
virtual image formed is 12 cm. Find the focal length of the lens.​

Answer 1

Answer:

Explanation:

In any case, to solve this problem you need to apply the spherical mirror equation: 1/f = 1/Do + 1/Di. BUT, you must be very careful when you are plugging in the values. There is an inherent fact in the problem: the mirror is CONVEX. The focal length of convex mirrors is NEGATIVE.

You should obtain Di = - 6 cm. The negative sign indicates that the image is VIRTUAL as all images in convex mirrors are. The 6 cm indicates a DIMINISHED image (relative to the object). The image is ERECT because ALL virtual images are erect relative to the object’s orientation. If there is another part(s) to the problem, it probably would ask for the magnification and the height of the image. The mag is (6 / 15 = 0.4 ) showing that it is diminished, and the image height would be: 3 * 0.4 = 1.2 cm (clearly diminished).

Answer 2

Answer:

the answers is Wright follows guys