Ray Optics Test...

A plano-convex lens of refractive index 1.5 and radius of curvature 30 cm is silvered at the curved surface. Now this lens has been used to form the image of an object. At what distance from this lens an object be placed in order to have a real image of the size of theobject

The focal lengths for violet, green and red light rays are f_V, f_G and f_R respectively. Which of the following isthe true relationship

The power of an achromatic convergent lens of two lenses is + 2D. The power of convex lens is + 5D. The ratio of dispersive power of convex and concave lenswill be

A combination of two thin convex lenses of focal length 0.3 m and 0.1 m will have minimum spherical and chromatic aberrations if the distance between them is

A bi-convex lens made of glass (refractive index 1.5) is put in a liquid of refractive index 1.7. Its focal lengthwill

Spherical aberration in a lens

The focal lengths of convex lens for red and blue light are 100 cm and 96.8 cm respectively. The dispersivepower of material of lens is

A point object Ois kept at a distance of OP = u. The radius of curvature of the spherical surface APB is CP = R. The refractive index of the media are n₁ and n₂ which are as shown in the diagram. Then,
(1) If n₁> n₂, image is virtual for all values of u.
(2) If n₂ = 2n₁,image is virtual when R > u.
(3) The image is real for all values of u, n₁ and n₂.
Here, the correct statement/s is/are

The focal length of a plano-convex lens is f and its refractive index is 1.5. It is kept over a plane glass plate with its curved surface touching the glass plate. The gap between the lens and the glass plate is filled by a liquid. As a result, the effective focal length of the combination becomes 2f. Then, the refractive index ofthe liquid is

A square card of side length 1 mm is being seen through a magnifying lens of focal length 10 cm. The card is placed at a distance of 9 cm from the lens. The apparent area of the card through the lens is