Physics, asked by gayathrijohns03, 1 year ago

Answer as clear as possible please....
How to identify whether a mirror is concave or convex if it is not specified in the question and only the magnification and image distance is given in the question...?

Answers

Answered by vaibhavaswal2
1
here is the most simple way
if the magnification and focus is given negative then it will be a convex mirror.
bcause in convex mirror magnification can never be positive..
hope it will help you...
Answered by Vedika25164
1
Hey mate here's your answer

The definitions of the principal axis, centre of curvature , radius of curvature , and the vertex , of a convex mirror are analogous to the corresponding definitions for a concave mirror. When parallel light-rays strike a convex mirror they are reflected such that they appear to emanate from a single point located behind the mirror. This point is called the virtual focus of the mirror. The focal length of the mirror is simply the distance between and. As is easily demonstrated, in the paraxial approximation, the focal length of a convex mirror is half of its radius of curvature.

There are, again, two alternative methods of locating the image formed by a convex mirror. The first is graphical, and the second analytical.
According to the graphical method, the image produced by a convex mirror can always be located by drawing a ray diagram according to foursimple rules:

An incident ray which is parallel to the principal axis is reflected as if it came from the virtual focus of the mirror.

An incident ray which is directed towards the virtual focus  of the mirror is reflected parallel to the principal axis.

An incident ray which is directed towards the centre of curvature of the mirror is reflected back along its own path (since it is normally incident on the mirror).

An incident ray which strikes the mirror at its vertex  is reflected such that its angle of incidence with respect to the principal axis is equal to its angle of reflection.

The validity of these rules in the paraxial approximation is, again, fairly self-evident.

As is easily demonstrated, application of the analytical method to image formation by convex mirrors again yields Eq. (352) for the magnification of the image, and Eq. (358) for the location of the image, provided that we adopt the following sign convention. The focal length  of a convex mirror is redefined to be minus the distance between points  and . In other words, the focal length of a concave mirror, with a real focus, is always positive, and the focal length of a convex mirror, with a virtual focus, is always negative. Table 6shows how the location and character of the image formed in a convex spherical mirror depend on the location of the object, according to Eqs. (352) and (358)  

Table 6: Rules for image formation by convex mirrors.

Position of objectPosition of imageCharacter of imageAt At Virtual, zero sizeBetween  and Between  and Virtual, upright, diminishedAt At Virtual, upright, same size


In summary, the formation of an image by a spherical mirror involves the crossingof light-rays emitted by the object and reflected off the mirror. If the light-rays actually cross in front of the mirror then the image is real. If the light-rays do not actually cross, but appear to cross when projected backwards behind the mirror, then the image is virtual. A real image can be projected onto a screen, a virtual image cannot. However, both types of images can be seen by an observer, and photographed by a camera. The magnification of the image is specified by Eq. (352), and the location of the image is determined by Eq. (358). These two formulae can be used to characterize both real and virtual images formed by either concave or convex mirrors, provided that the following sign conventions are observed:

The height of the image is positive if the image is upright, with respect to the object, and negative if the image is inverted.

The magnification of the image is positive if the image is upright, with respect to the object, and negative if the image is inverted.

The image distance is positive if the image is real, and, therefore, located in front of the mirror, and negative if the image is virtual, and, therefore, located behind the mirror.

The focal length of the mirror is positive if the mirror is concave, so that the focal point  is located in front of the mirror, and negative if the mirror is convex, so that the focal point  is located behind the mirror.

Note that the front side of the mirror is defined to be the side from which the light is incident.

Hope this may help you.....If yes then pls mark it as a brainlist answer pls pls...
Similar questions