The minimum number of rays required to locate the image formed by a spherical mirror is _____.
Two
An image point is located by finding where the reflected rays from a point on the object meet (or appear to meet). A single point in a plane is fixed by the intersection of at least two lines, so we need at least two reflected rays whose intersection marks the image of that object point.
In mirror ray-diagrams we usually have four standard rays to choose from (a ray parallel to the principal axis reflecting through the focus, a ray through the focus reflecting parallel to the axis, a ray through the centre of curvature retracing its path, and a ray to the pole reflecting symmetrically about the axis). Any two of these is sufficient to fix the image; the third or fourth ray only confirms the result.
Hence, the minimum number of rays required is Two.
Which one of the following processes is responsible for the glittering of air bubbles rising through water?
What was the chief objective of the 'Wahabi movement'?
What causes the mottling of the dental enamel?
Rajat has hypermetropia. What type of lens will the ophthalmologist recommend to correct his vision?
The impression of an image persists on the retina for about _________ of a second.
When light passes from one medium to another there is a change in its direction, this phenomenon is called ________.
What type of image formed by a concave mirror on the screen when the distance between object and mirror is higher than the focus?
Who first stated the principle of refraction that postulates that every substance has a specific bending ratio – 'refractive index'?
Convex and concave mirrors are examples of?
In an optical fibre the signal is transmitted:
Who was the first one to use a glass prism to obtain the spectrum of sunlight?
Twinkling of stars is due to:
In which a convex mirror is used?
A. Rear View mirrors in vehicles
B. Glass windows
C. Makeup Mirror
D. Kaleidoscope
An object is placed 10 cm in front of a lens. The image formed is real, inverted and of same size as the object. What is the focal length and nature of the lens?
The power of a lens is -2.5 D. The type of lens and its focal length are respectively: