8. An erect and enlarged image of an object is formed on a screen.Explain how this could be possible

This can be possible through the use of a concave mirror or a converging lens. Here's a step-by-step explanation:

1. Concave Mirror: When an object is placed closer to a concave mirror than its focal point, the light rays reflecting off the mirror diverge, or spread out. If you trace these rays back, they appear to come from a point behind the mirror. This forms a virtual, erect, and magnified image of the object.

2. Converging Lens: When an object is placed very close to a converging lens, the light rays refracting through the lens diverge. If you trace these rays back, they appear to come from a point on the same side of the lens as the object. This forms a virtual, erect, and magnified image of the object.

In both cases, to project the image onto a screen, an additional lens (a projection lens) is needed to convert the diverging light rays into a real image. The projection lens takes the diverging light rays and refracts them so they are converging again, forming a real, inverted image on the screen. However, if the screen is translucent and viewed from the opposite side, the image will appear erect and enlarged.