Question

The real image of an object placed between \( f \) and \( 2f \) from a convex lens can be seen on a screen placed at the image location. If the screen is removed, is the image still there? Explain. Plane and convex mirrors produce virtual images of objects. Can they produce real images under some circumstances? Explain.

Hint:

Key ideas:

Real image exists even without a screen.
Plane mirror → always virtual image.
Convex mirror → real image possible only for virtual objects.

Answer 1

Real and Virtual Images in Lenses and Mirrors
1. Real Image of a Convex Lens:
- When an object is placed between the focal point \( f \) and twice the focal length \( 2f \) of a convex lens, a real, inverted, and magnified image is formed on the other side of the lens.
- This image can be projected onto a screen at the image location because light rays actually converge there.
- If the screen is removed: The image is still "there" in the sense that the light rays converge at that location. However, without a screen to catch the rays, the image cannot be seen by our eyes directly; it exists in space as a real convergence of light.

2. Images by Plane and Convex Mirrors:
- Plane and convex mirrors always produce virtual, erect, and laterally inverted images of objects.
- The image is virtual because light rays appear to diverge from behind the mirror; they do not actually converge.
- Can they produce real images?
- No, plane and convex mirrors cannot produce real images under normal circumstances because they reflect light outwards; the reflected rays never actually converge.
- Only concave mirrors can produce real images if the object is placed beyond the focal point.

Summary:
- Real images are formed where light rays actually converge and can be projected onto a screen.
- Virtual images are formed where rays appear to diverge from; they cannot be projected onto a screen.
- Plane and convex mirrors always produce virtual images; they cannot produce real images.