A convex mirror is used as a rear view mirror and for security purposes.Ī number of parallel rays hit a convex mirror, they reflect outwards and travel directly away from an imaginary focal point (F). A convex mirror can be compared to the outside of a balloon. Credit: Key Differences Convex MirrorĪ spherical mirror whose reflecting surface is curved outwards is called a convex mirror. Concave mirrors are the reflecting objects that are used in reflecting telescope. A concave mirror can be compared to the inside of the spoon. Here is a formula to calculate the number of images for diffused reflection of light: Concave MirrorĪ spherical mirror, whose reflecting surface is curved inwards, that is, faces towards the centre of the sphere, is called a concave mirror. The number of images becomes infinite when the angle between the two mirrors is zero i.e, they are parallel. If we decrease the angle, the number of images get increased. The number of images varies as per the angle between two mirrors. Infinite images will be formed in multiple reflections, as each image is the result of another image.

This type of reflection is only possible when the intensity of the light becomes so low that we cannot see it. Read About: MSc Physics Multiple Reflectionįor both regular and diffused reflection of light, a single mirror is used while when we take two mirrors, a single source of light can be reflected multiple times. In diffused reflection, the incident ray falls on different points and gets reflected in an entirely different direction and hence, we see non-shiny objects. Thus, the comparison of both the angles of reflection on such rough surfaces is completely distorted. All these things hamper the quality and brightness of reflection. The common surfaces which can be used for diffusion of light are comparatively rough as they are made up of different material than glass and contain some marks, scratches, dust or dents. To explore the meaning of diffused reflection, let us consider reflective surfaces other than mirrors.

Due to this minimal variation, we can say that all the haziness and the blurriness is completely gone.Ĭheck Out: BSc Physics Diffused Reflection As it is coated, the surface totally reflects all the light which falls on it i.e, there is not much variation in both the angles of reflection at multiple points. This mirror used for reflection of light is not the regular mirror we see around us, rather it is a glass which is heavily coated with a uniform layer of highly reflective material such as a powder. Regular Reflection can also be referred to as Specular Reflection and is simply understood by using a plane mirror. Following are the main three types of reflection:Īlso Read: Class 12 Physics Chapters Regular Reflection Whenever we change the basic elements or the form of basic elements involved in this phenomenon, the result also varies. While exploring the basics of the reflection of light, it is also important to go through the different types of reflection. This derivation makes use of the calculus of maximum-minimum determination and the definitions of the triangle trig functions.Quick Read: Experiment With Diverse Career in Physics Types of Reflection We make use of the index of refraction, defined as n=c/v. Snell's Law can be derived from this by setting the derivative of the time =0. Fermat's Principle for Refractionįermat's Principle: Light follows the path of least time. This derivation makes use of the calculus of maximum-minimum determination, the derivative of a square root, and the definitions of the triangle trig functions. This may be found by setting the derivative of L with respect to x equal to zero. Since the speed is constant, theminimum time path is simply the minimum distance path.

The law of reflection can be derived from this principle as follows: Of course the straight line from A to B is the shortest time, but suppose it has a single reflection. The law of reflection gives the familiar reflected image in a planemirror where the image distancebehind the mirror is the same as the object distance in front of themirror.įermat's Principle: Light follows the path of least time. This law of reflection can be derived from Fermat's principle. Both angles are typically measured with respect to the normal to the surface. Reflection and Fermat's Principle Law of ReflectionĪ light ray incident upon a reflective surface will be reflected at an angle equal to the incident angle.

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