Chapter 2, Problem 1CQ

What are the differences between real and virtual images? How can you tell (by looking) whether an image formed by a single lens or mirror is real or virtual?

To determine

The difference between real and virtual images. How can a real and virtual image can be distinguished just by looking?

Answer to Problem 1CQ

When the rays after reflection from mirror or refraction from lens actually meet, a real image is obtained. On the other hand, when the rays just appear to meet, a virtual image is formed. We can distinguish between the two just by looking as a real image is inverted but a virtual image is erect.

Explanation of Solution

Introduction:

An image of an object is formed when rays from the object reflect off a mirror or refract from a lens meet or appear to meet at a point. The characteristics of the image are determined by making ray diagrams.

The difference between real and virtual image is:

A real image is obtained when rays from the object after reflecting from the mirror or undergoing refraction from lens actually meet at a point. A real image can be obtained on a screen and a real image is always inverted.

On the other hand, a virtual image cannot be obtained on a screen because the rays after reflection or refraction do not actually meet but appear to meet. A virtual image is always erect.

One can tell whether the image is real or virtual just by looking if the image is inverted or erect. A real image is always inverted and a virtual image is always erect. In a metal spoon, we can see the inverted image formed at the concave side while erect image at the back side.

Conclusion:

Unlike virtual image, a real image can be obtained on screen. A real image is inverted and a virtual image is erect.