The image formed by a concave mirror is observed to be virtual, erect and larger than the object. Where should be the position of the object? (a) Between the principal focus and the centre of curvature (b) At the centre of curvature (c) Beyond the centre of curvature (d) Between the pole of the mirror and its principal focus.

In the context of concave mirrors, a virtual image is formed when the light rays diverge after reflecting off the mirror. The brain perceives these diverging rays as coming from behind the mirror, creating an image that cannot be projected onto a screen. This type of image formation is different from real images, where the reflected rays converge at a point.
Virtual images are always upright (or erect) and are typically seen in situations where the object is positioned very close to the mirror. This specific placement of the object results in certain unique properties of the image formed, such as being larger or smaller than the object itself. Understanding these characteristics is essential for solving problems related to image formation by concave mirrors.

An erect image is an image that appears right-side up, as opposed to an inverted image which is upside down. In concave mirrors, erect images are formed when the object is placed between the pole and the principal focus of the mirror.
For instance, if you place an object very close to a concave mirror, specifically within the focal length, the image formed will be virtual, erect, and magnified. This happens because the light rays reflecting off the mirror diverge, and the brain interprets these diverging rays as originating from a point behind the mirror.
The fact that the image is erect helps in identifying the correct position of the object in questions related to concave mirrors.

Determining the position of the object in a concave mirror setup is crucial for predicting the nature of the image formed. For a virtual, erect, and magnified image, the object must be placed between the pole (the vertex of the mirror) and the principal focus (the focal point where light rays converge if parallel to the principal axis).
The principal focus (F) is a point on the principal axis of the mirror where light rays parallel to the axis converge after reflection. The pole (P) is the point at the center of the mirror's surface. When the object is between these two points (P and F), the light rays after reflection from the mirror appear to diverge, forming a virtual image behind the mirror.

• The image will be virtual and cannot be projected on a screen.
• The image will be erect, rather than inverted.
• The image will be larger than the object.

Understanding this relationship between the object's position and the resulting image makes it easier to solve related physics problems effectively.