JAMB - Physics (2022 - No. 4)
An object 40 cm high is 30cm from the pin hole camera. If the height of the image formed is 20 cm. What is the distance of the image from the pin height?
15 cm
70 cm
40 cm
40 cm
คำอธิบาย
M → \(\frac{Hi}{Ho}\) = \(\frac{Di}{Do}\)
where M is the magnification, Hi is the height of the image, Ho is the height of the object, Di is the distance from the lens to the in-focus projected image, and Do is the distance from the object to the lens.
But Di = \(\frac{Hi * Do}{Ho}\) → \(\frac{20 * 30}{40}\)
Image distance(Di) = 15cm