WAEC - Physics (2017 - No. 32)
A converging lens of focal length 10cm forms an erect image three times the size of the real object. Calculate the distance between the image and the object.
6.6cm
11.1cm
13.3cm
20.0cm
คำอธิบาย
Given, image size = 3U
object size = U
focal length = 10cm
lens to object distance = \(\frac{focal length \times object size}{image size}\)
= \(\frac{10 \times u}{3u} = 3.33\)
distance between image and object = 10 + 3.33 = 13.33cm