Class 10, lightreflection and refraction tagged with. List four properties of the image formed by a concave mirror, when object is placed between focus and pole of. Image formation in a concave mirror place an object before a concave mirror for each of the following object positions shown below and obtain its image. The focus of a concave mirror is a point on the principal axis through which the light rays incident parallel to principal axis, pass after reflection from the mirror. Chapter 4 reflection of light lakhmir singh and manjit. To study reflection in concave mirror physics kids projects, physics science fair project, pyhsical science, astrology, planets solar experiments for kids and also organics physics science ideas for cbse, icse, gcse, middleschool, elementary school for 5th, 6th, 7th, 8th, 9th and high school students. Figure 1 shows an example of reflection from a plane surface such as mirror. Chapter 7 reflection of light icse selina solutions for. Two convenient rays that are chosen to construct the image by a spherical mirror for a given object. The distance between the pole p and principal focusf of a spherical mirror is called the focal length of the mirror. The sun is not at an infinite distance from the earth. A concave mirror of focal length 20cm forms a real image two times the size of the object.
Lakhmir singh physics class 10 solutions reflection of light. A light bulb is 60 cm from a concave mirror with a focal length of 40 cm. Chapter 10 light reflection and refraction is one of the important chapters in class 10 science and the expected marks weightage of the chapter according to the latest marking scheme is 7 marks. The schematic representation of these mirrors is shown in fig. On the contrary, in a concave mirror, the reflecting surface bulges inwards the main difference between a convex and concave mirror lies in the image formed by the two mirrors, i. When light rays that are parallel to the principal or optical axis reflect from the surface of a concave mirror in this case, light rays from the owls feet, they converge on the focal point red dot in front of the mirror. The focal point ffor a concave mirror is the point at which all parallel light rays converge. The image formed by a concave mirror varies in size depending on the position of the object with respect to the mirror. Rays of light parallel to the principal axis after reflection from a concave mirror meet at a point converge on the principal axis. From second law of reflection, we know that angle of incidence is equal to angle of reflection. A ray of light passing through the centre of curvature of a concave mirror or a ray directed in the direction of centre of curvature of a convex mirror is reflected back along the same path after reflection. The distance of the focus from the pole of the concave mirror is called its focal length. In this lab, you will study reflection of light from different mirrors. A concave mirror of focal length 10cm forms a sharp image at 40cm from the mirror.
A convex mirror or diverging mirror is a curved mirror in which the reflective surface bulges towards the light source. The heat produced due to the concentration of sunlight ignites the paper. When a concave mirror is to produce a sharp image of an object, the image is formed at the focus. Light reflection and refraction important questions and answers.
Reflection at curved surfaces form 2 physics notes. Ncert solutions for class 10 science chapter 10 light reflection and refraction. C the reflected light rays intersect at a focal point f, in front of the mirror. The incident ray, the reflected ray and the normal to the mirror at the point of incidence all lie in the same plane. Concave mirrors converge light to one prime focus point. When light falls on a highly polished surface like a mirror most of the light is sent back into the same medium. For such spherical mirrors, we assume all angles are small even. As ray of light falls normally on mirror, this means that angle of incidence is 0o. In a concave mirror, parallel light rays get converged focused upon reflection.
Lakhmir singh and manjit kaur solutions for class 10 physics cbse, 4 reflection of light. In a convex mirror reflection of light takes place at the convex surface or bent out surface as shown below in the figure. The phenomenon of bouncing back of light from a surface is known as the reflection of light. For spherical mirrors, the paraxial approximation is possible for mirrors of small. Selina concise physics class 9 icse solutions reflection. Each point of an illuminated object emits a continuum of light rays in a range of directions. Convex mirrors reflect light outwards, therefore they are not used to focus light.
Such mirrors always form a virtual image, since the focal point f and the centre of curvature 2f are both imaginary points inside the mirror, that cannot be reached. If the object height is 10 cm, determine by scale drawing. To study reflection in concave mirror physics astronomy. The video in english explains about different types of mirror i. A point on the principal axis of a spherical mirror where the rays of light parallel to the principal axis meet or appear to meet after reflection from the mirror. In this chapter the reflection of light from mirrors is discussed. To the eye, the ray seems to come from behind the mirror. Science plane, concave and convex mirrors and reflection. Two convenient and commonly used rules of reflection for concave mirrors are. Position the light source so the crossed arrow target is aimed at the concave mirror and the concave surface of the mirror faces the light source. Reflection of light a highly polished surface, such as a mirror, reflects most of the light falling on it. A spherical mirror whose reflecting surface is curved outwards, is called a convex mirror.
The study of light is divided into two categories 1. In fact, if some light from the sun was collected by a concave mirror, then it would converge at the focal point. Chapter 34a reflection and mirrors geometrical a powerpoint presentation by paul e. A most significant property of light is that it travels in a straight line from its source to whatever surface it touches. Verify the law of reflection and investigate the properties of spherical mirrors. Mirror, mirror on the wall eight lessons on mirrors. A ray of light is incident on a plane mirror at an. The light of the flashlight in figure 4 hits the disco ball and is then mirror reflected towards the paper. Determine graphically the position of the object and magnification of the image. Multiple choice questions on light reflection and refraction question 9. Light, reflection, and color characteristics of light light is an electromagnetic wave. The focal length is the distance between the focal point and the mirror. The focal point f of a concave mirror is the point at which a parallel beam of. In a concave mirror reflection of light takes place at the concave surface or bentin surface as shown below in the figure.
In fact, this spot of light is the image of the sun on the sheet of paper. Reflection of a point object in an arbitrary curved mirror. Concave and convex mirrors ray diagram for convex and. Class 10 reflection of light test paper with solutions. Light always reflects according to the law of reflection, regardless of whether the reflection occurs off a flat surface or a curved surface. Images formed by concave mirror using ray diagram class. For a convex mirror, it is the point on the principal axis from which such rays appear to emanate. The position of object should be a at the focus b at the centre of curvature c between focus and centre of curvature d beyond centre of curvature. Rays of light parallel to the principal axis after reflection from a convex mirror get diverged and appear to come from a point behind the mirror.
If the outside surface is polished, is it a convex mirror. A concave mirror is composed of a reflective surface with its sides curved closer in. Mcq questions for class 10 science light reflection and. A 10 mm long awl pin is placed vertically in front of a concave mirror. The concave mirror has a reflection surface that curves inward, resembling a portion of the interior of a sphere. Because none of the rays actually emanate from the image, it is called a virtual image.
Geometrical optics in the study of how light behaves, it is. The image formed by concave mirror is real, inverted and of the same size as that of the object. The reflected ray moves parallel to the principal axis by the principle of reversibility of light. Figure 33b shows the reflection of several light rays at a curved mirror. Light rays near and parallel to the principal axis are reflected from the concave mirror and converge at the focal point. Reflection from spherical mirrors kindle education. You got the approximate focal length of the concave mirror by measuring the distance of the image from the mirror. Note the location, orientation upright or inverted, relative size larger or smaller than object. A ray of light from the top of the chess piece reflects from the mirror. All the solutions of reflection of light physics explained in detail by experts to help students prepare for their cbse exams. Curved mirror problem answer key use the mirror equation and the magnification ratio to solve the following problems.
Reflection of light introduction olympus life science. But an image is only formed at the focus by a concave mirror when the object is at an infinite distance. There are two kinds of spherical mirrors, concave and convex. Spherical mirrors a modern compter hovers between the obsolescent and the non existent sydney brenner. Therefore, the light ray will be reflected back along the same path. A 5cmlong mascara brush is held upright 20 cm from. Each mirror has a radius of curvature r which is in. Lets explore the ray tracing technique to figure out the properties of images when things are kept in front of a concave or a convex mirror. Image of same size is obtained in plane mirror and it is always virtual.
The focal point is the point in space at which light incident towards the mirror and traveling parallel to the principal axis will meet after reflection. Electromagnetic waves are ultimately produced by an accelerating charge. The light spots on the paper can be seen from all directions. Reflection by plane mirror laws of reflection group experiment lesson 3 2. Consider the case where the shape of the mirror is such that light rays parallel to the axis of the mirror are all focused to a common spot a distance f in front of the mirror. When you flip that switch in the bathroom to brush your teeth, how does light move from the light bulb, to the mirror, and into your eyes. Why, then, can a concave mirror form a sharp image of the sun at the focus. If the inside surface of the spherical mirror is polished, it is a concave mirror. Therefore, they are also called converging mirrors. As shown below, an electromagnetic wave is a transverse wave consisting of mutually perpendicular oscillating electric and magnetic fields.
We have already looked at reflection by plane mirrors in topic 8. What is the angle of reflection of the light ray off the second mirror r1 i1. Using reflection laws allows one to determine the image location for an object. Light reflection and refraction notes for class 10.
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