Question

Student did an experiment with convex lens.He puts an object at different distances 25 cm, 30 cm,40 cm 60 cm and 120 cm from the lens. In each case he measured the distance of the image from the lens. His results are 100cm,24cm, 60 cm and 30 cm and 40 cm. Unfortunately, the order is wrong.Rewrite the image distance in correct order. NOTE: Earliest ans=Brainliest answer !​

Answer 1

Answer:

100,60,40,30,24

Step-by-step explanation:

For a convex lens if we place an object at its centre of curvature on one side, it's image is formed at same distance from optical centre on other side i.e, at the centre of curvature on other side.

By observing the observations the possible values of centre of curvature can be

30 cm, 40 cm, or 60 cm

as for each of these object distances there is an image distance with same values.

Thus, focus point of lens could be

15 cm, 20 cm, or 30 cm

As f = R/2 where R is radius of curvature.

Now, using lens formula with proper sign convention

(1÷v) - (1/u) = (1/f)

for all 3 possible values of focus and observations of object distance we can se that f = 20 cm satisfies all conditions, thereby giving order of images as :

100,60,40,30 and 24 for 25,30,40,60 and 120 respectively .