| English | Virtual image |
|---|---|
| Bahasa Melayu | Imej maya |
| 中文 | 虚像 |
Definition
An image formed where light rays only appear to come from, which cannot be captured on a screen.
In exam terms
A virtual image is an image formed where light rays only appear to come from, but do not actually meet. Because no real rays cross at that point, a virtual image cannot be caught on a screen; you can only see it by looking into the lens or mirror.
A plane mirror always forms an upright virtual image the same size as the object, at an equal distance behind the mirror. A converging lens forms a magnified, upright virtual image when the object is inside the focal length, which is how a magnifying glass works.
Example sentence of correct use: The enlarged, upright letters seen through a magnifying glass form a virtual image. A virtual image has no unit and is described by distance (m) and magnification.
Do not confuse it with a real image
Do not confuse a virtual image with a real image. A real image forms where rays truly converge, so it can be projected onto a screen and is inverted for a single converging lens.
The screen test settles it: a virtual image never appears on a screen, a real image does.
In Paper 2 you may be asked to state the characteristics of the image (virtual, upright, magnified or diminished), or to explain why the image cannot be caught on a screen. In a ray diagram, the virtual image is found by extending the outgoing rays backwards as dashed lines until they appear to cross.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)