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प्रश्न
Define the term ‘focal length of a mirror’.
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उत्तर
When rays of light parallel to the principal axis of a mirror are incident on it, the rays after reflection either converge at a point or appear to diverge from a point. The distance of that point from the pole of the mirror is known as the focal length of the mirror.
संबंधित प्रश्न
A 5 mm high pin is placed at a distance of 15 cm from a convex lens of focal length 10 cm. A second lens of focal length 5 cm is placed 40 cm from the first lens and 55 cm from the pin. Find (a) the position of the final image, (b) its nature and (c) its size.
Two convex lenses, each of focal length 10 cm, are placed at a separation of 15 cm with their principal axes coinciding. (a) Show that a light beam coming parallel to the principal axis diverges as it comes out of the lens system. (b) Find the location of the virtual image formed by the lens system of an object placed far away. (c) Find the focal length of the equivalent lens. (Note that the sign of the focal length is positive although the lens system actually diverges a parallel beam incident on it.)
According to new Cartesian sign conventions, all the distances are measured from the ______.
Region I and II are separated by a spherical surface of a radius of 25 cm. An object is kept in the region I at a distance of 40 cm from the surface. The distance of the image from the surface is ______.
Which of the following correctly states the relation for refraction at a spherical surface?
In the Cartesian sign convention, distances measured in the direction of incident light are taken as:
Which set of variables is primarily involved in refraction at a spherical surface, as opposed to refraction at a plane surface?
Which effect is common for image shift in refraction at a plane surface?
An object is placed at a distance of 100 cm in air from a convex spherical surface of glass of refractive index 1.5. The radius of curvature is 20 cm. What is the image distance?
When a light ray strikes a curved surface and refracts, the amount of bending depends on:
