Chapter 13.2, Problem 9R

To determine

The formation of image by concave lens.

Answer to Problem 9R

The image is smaller than the object and all the images are virtual, upright.

Explanation of Solution

The meaning of concave is curved inward. When light rays approaches the lens, bent to the outward.

There are two conditions:

1. When object is at infinity:

When the object is placed in infinite, image formed at focus point F₁. The formed image is virtual and smaller than original.

  

2. When object is between infinity and centre of lens:

For this condition image is formed between focus and optical centre of the lens. Image is virtual and erect.

  

Conclusion:

Hence, the image is smaller than the object and all the images are virtual, upright.