What is a virtual image? Give one situation where a virtual image is formed.

Hint- To give the answer of this question, we use the basic theory of optics. Optics is the branch of physics in which we study about light. First we see the definition of virtual image. Virtual image is formed by Lens and mirror when diverging rays appear to meet at point.
Point of intersection of reflected or refracted rays is called image.

Step-By-Step answer:
There are two types of image.
Real image
Virtual image

Here we will discuss virtual images.
Point of intersection of diverging reflected or refracted rays is called virtual image.

Here we see in a concave mirror, if an object is in between focus and pole, after reflection, the virtual image is found, which is formed by diverging rays behind the mirror and the image is larger than the object.
Here, the real object is at ‘o’ and the virtual image is at ‘i’. And the pole is at ‘p’.
Also in lens after refraction virtual image formed.
Example-
The situation of this condition is used by dentists where a concave mirror is used and the object is placed very close to the mirror(between F and P) so that the image formed is magnified , virtual and erect.

Virtual images are also formed in side mirrors in automobiles. In this case, image height is much smaller than object height and erect.
Image formed in a plane mirror is always virtual and image height is equal to object height.

Note – Virtual image is always erect but real image is never erect , it is always inverted . The height of the virtual image formed may be larger or smaller than the object height. Virtual images cannot be obtained on a screen. Although real images can be obtained on the screen and it is formed by converging rays.