Ray Optics and Optical Instruments

The refractive index of prism is = 3 and the ratio of the angle of minimum deviation to the angle of prism is one. The value of angle of prism is .

For the thin convex lens, the radii of curvature are at 15 cm and 30 cm respectively. The focal length of the lens is 20 cm. The refractive index of the material is :

1. 1.2
2. 1.5
3. 1.4
4. 1.8

Given below are two statements : In the light of the above statements, choose the correct answer from the options given below :

1. Both Statement I and Statement II are true
2. Statement I is true but Statement II is false
3. Statement I is false but Statement II is true
4. Both Statement I and Statement II are false

An effective power of a combination of 5 identical convex lenses which are kept in contact along the principal axis is 25D. Focal length of each of the convex lens is:

1. 50 cm
2. 20 cm
3. 25 cm
4. 500 cm

A light ray is incident on a glass slab of thickness 4 3 cm and refractive index 2. The angle of incidence is equal to the critical angle for the glass slab with air. The lateral displacement of ray after passing through glass slab is cm. (Given 15 = 0.25)

The distance between object and its 3 times magnified virtual image as produced by a convex lens is 20 cm. The focal length of the lens used is cm.

The refractive index of a prism with apex angle A is A/2. The angle of minimum deviation is :

1. m=180 -3A
2. m=180 -4A
3. m=180 -2A
4. m=180 -A

Light from a point source in air falls on a convex curved surface of radius 20 cm and refractive index 1.5. If the source is located at 100 cm from the convex surface, the image will be formed at cm from the object.

The distance between object and its two times magnified real image as produced by a convex lens is 45 cm. The focal length of the lens used is cm.

In an experiment to measure the focal length (f) of a convex lens, the magnitude of object distance (x) and the image distance (y) are measured with reference to the focal point of the lens. The y-x plot is shown in figure. The focal length of the lens is cm. [figure]