Differentiate between a shadow and an image formed by a plane mirror, highlighting two key differences.
A shadow is formed when an opaque object blocks light, creating a dark region where light cannot reach a surface. It is always dark, shows only the outline of the object, and does not provide any detail or colour of the object. An image, on the other hand, is formed due to the reflection of light by a mirror. An image can be virtual (like in a plane mirror), shows details and colours of the object, and can be inverted or erect. Also, a shadow requires a screen, while an image from a plane mirror is virtual and cannot be caught on a screen.
Explanation
Key points for grading: Distinction based on mode of formation (blocking light vs. reflection). Difference in appearance (dark outline vs. detailed/coloured). Difference in nature (not an optical reproduction vs. optical reproduction). Requirement of a screen for shadow vs. virtual image.