I was asked to compare my measured focal length to my calculated focal length. My calculated focal length I figured out by using the formula:
1/di + 1/do = 1/f
Would my measured focal length = my di?
I only measured by di and do in the actual experiment.
The experimental values I have are:
f=12
object location = 2.5f
object distance from lens = 35 cm
image distance from lens = 27 cm
The "measured focal length" is the value of f that you compute using the lens formula and your measured values of di and do. In this case, that would be given by
1/27 + 1/35 = 1/f,
which leads to f = 15.2 cm
According to your measurements, the focal length is not 12 cm.
If you were supposed to have an object location of 2.5 f and the focal length were really 12 cm, the object should have been placed 30 cm from the lens, not 35.
How did you get the "experimental value" of f = 12 cm? Did they tell you what it is?
To determine whether your measured focal length is equal to your di (image distance), you need to understand the measurements you have taken.
In the given formula:
1/di + 1/do = 1/f
- di represents the image distance, which is the distance between the lens and the projected image.
- do represents the object distance, which is the distance between the lens and the object being viewed.
- f represents the focal length, which is the distance between the lens and the point where the light rays converge.
Based on the formula, the image distance (di), object distance (do), and focal length (f) are interconnected. If you only measured di and do in the actual experiment, you won't have the measured focal length.
To compare your measured focal length with your calculated focal length, you need to either measure the focal length directly using another method or calculate it using the given measurements of di and do. Without a direct measurement or additional information, you can't determine the measured focal length using only di and do.