Chapter 30, Problem 3A

Distinguish between a virtual image and a real image.

To determine

To distinguish: Real image and virtual image.

Explanation of Solution

Introduction:

Image formed by a lens or a mirror is actually determined by the position where the light rays intersect and how are they incident.

We have two types of images formed by a lens: real image and virtual image. These image formation are dependent upon the distance of the object from the lens and also on the nature of the lens to converge or diverge the light rays.

Convex lenses and concave mirror form real images in most of the cases except for the one in which the object is placed between the focus and the optical centre. These images are formed when the light rays actually intersect and hence they can be obtained on a screen although they are inverted. While concave lenses and convex and plane mirrors form virtual image for all the positions of the object. These images are formed by imaginary intersection of light rays by producing them back and thus they cannot be obtained on a screen although they are formed erect.

Conclusion:

Hence, the main difference between real and virtual image is that real image can be plotted on a screen and are inverted while virtual image cannot be plotted on the screen and are erect.