Rules for obtaining images formed by convex mirror They are used in the field of solar energy to focus sun’s rays for heating solar furnaces.They are used by dentists to see large images of teeth.As reflectors in torches, vehicle head-lights and search lights to get powerful beams of light.The image formed is:at infinity, real and inverted and highly enlarged. The image formed is:behind the mirror, virtual and errect, larger than the object.Ĭase 2: When an object is placed at the focus (at F), the reflected rays of light pass through focus and centre of curvature. The two reflected rays do not intersect each other on the left side and thus, are produced backwards to form an image. Rule 4: A ray of light which is incident at the pole is reflected back making the same angle with the principal axis.Ĭase 1: When an object is placed between the pole and focus (between P & F) of the concave mirror, then the ray of light will pass through focus and centre of curvature. Rule 3: When a ray of light passes through the focus, it becomes parallel to the principal axis after reflection. Rule 2: When a ray of light passes through the centre of curvature, it gets reflected back along the same path. Rule 1: When a ray of light which is parallel to the principal axis gets reflected, it passes through its focus. Rules for obtaining images formed by concave mirror Principal focus of a convex mirror: A point on principal axis from which a beam of light rays appear to diverge after being reflected from the convex mirror. Principal focus of concave mirror: The point on the principal axis to which all the light rays which are parallel to the axis converge after reflection from the concave mirror.įocal length of concave mirror: The distance between pole and principal focus. Principal axis: The straight line passing through centre of curvature and pole.Īperture of mirror: The portion of mirror from which reflection of light takes place.
0 kommentar(er)
