Question

an object and a screen are d cm apart. a lens is placed in a position so as to produce on the screen an image which is larger than the object. if the lens is now moved a distance of d cm, a second image is formed on the screen which is smaller than the object. calculate the focal length of the lens.

Answer 1

To calculate the focal length of the lens in this scenario, we can use the lens formula and solve for f using the given information.

Step-by-step explanation:

In this question, a lens is placed between an object and a screen, and when the lens is in a certain position, it produces a larger image on the screen. When the lens is moved a distance of d cm, a second image is formed on the screen that is smaller than the object. To calculate the focal length of the lens, we can use the lens formula:

1/f = 1/v - 1/u

where f is the focal length of the lens, v is the image distance, and u is the object distance.

By using the given information, we can find the values of v and u for both cases and solve for f.