NCERT Question 9 - Chapter 10 Class 10 - Light - Reflection and Refraction

One-half of a convex lens is covered with a black paper. Will this lens produce a complete image of the object? Verify your answer experimentally. Explain your observations.

Answer

Even if one half of a convex lens will be covered with a black paper, it would still produce the complete image but the image will be a bit fainter

Experiment

We follow these steps

1. Take a candle and a convex lens
2. Adjust the position of lens until a sharp image of candle is observed.
3. We will observe that the image formed is real, inverted and sharp.
4. Note down the position of the convex lens.
5. Now, cover the lower half of the convex lens with black paper
6. And place the convex lens at the same position.
7. We will observe that

The image produced will be complete.

But the image observed now will be fainter.

Observations

Even when half of the mirror is covered with black paper, it would still produce a complete image but the image produced would be fainter (of lesser intensity) than the image produced when half mirror was not covered.