Ray Optics and Optical Instruments

In the diagram given below, there are three lenses formed. Considering negligible thickness of each of them as compared to |R1| and |R2|, i.e., the radii of curvature for upper and lower surfaces of the glass lens, the power of the combination is [figure]

1. - 16 ( 1|R1|- 1|R2| )
2. - 16 ( 1|R1|+ 1|R2| )
3. 16 ( 1|R1|+ 1|R2| )
4. 16 ( 1|R1|- 1|R2| )

Given is a thin convex lens of glass (refractive index ) and each side having radius of curvature R. One side is polished for complete reflection. At what distance from the lens, an object be placed on the optic axis so that the image gets formed on the object itself?

1. R/
2. R/(2 -1)
3. R/(2 -3)

The driver sitting inside a parked car is watching vehicles approaching from behind with the help of his side view mirror, which is a convex mirror with radius of curvature R=2 m. Another car approaches him from behind with a uniform speed of 90 km/hr. When the car is at a distance of 24 m from him, the magnitude of the acceleration of the image of the car in the side view mirror is ' a '. The value of 100a is m/s2.

A symmetric thin biconvex lens is cut into four equal parts by two planes AB and CD as shown in figure. If the power of original lens is 4D then the power of a part of the divided lens is [figure]

1. 2D
2. 8D
3. 4D
4. D

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

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

The following figure represents two biconvex lenses L1 and L2 having focal length 10 cm and 15 cm respectively. The distance between L1 & L2 is : [figure]

1. 25 cm
2. 35 cm
3. 10 cm
4. 15 cm

Critical angle of incidence for a pair of optical media is 45 . The refractive indices of first and second media are in the ratio:

1. 1 : 2
2. 1 : 2
3. 2 : 1
4. 2 : 1

The position of the image formed by the combination of lenses is : [figure]

1. 15 cm (right of second lens)
2. 30 cm (right of third lens)
3. 30 cm (left of third lens)
4. 15 cm (left of second lens)

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