Question

A parallel beam of white light falls on a convex lens. Images of blue, yellow and red light are formed on the other side of the lens at a distance of 20 cm, 20.5 cm and 21.4 cm respectively. The dispersive power of the material of the lens will be: 

Solution

Correct option is

14/205

SIMILAR QUESTIONS

Q1

The angle of a prism is A and if the angle of minimum deviation is 180 – 2A, then the refractive index of the material of the prism is:  

Q2

An equilateral prism is placed on the prism table of a spectrometer in the position of minimum deviation. If the angle of incidence is 60o, the angle of deviation of the rays is:    

Q3

A ray falls on a prism ABC (AB = BC) and travels as shown in the figure. The minimum refractive index of the material should be:

                                                                                        

Q4

Three glass prism AB and C of the same refractive index are placed in contact with each other as shown in the diagram below with no air gap between the prisms. A monochromatic ray of light OP passes through the prism assembly and emerges as QR. The conditional minimum deviation is satisfied in the prisms: 

                                                                 

Q5

 

Angle of minimum deviation for a prism of refractive index 1.5 is equal to the angle of prism. The angel of the prism is:

(Given cos 41o ≈ 0.75) 

Q6

A prism (μ = 1.5) has the refractive angle of 30o. The deviation of a monochromatic ray incident normally on its one surface will be (sin 48o36 = 0.75):  

Q7

A thin prism P1 with angle 4o and made from glass of refractive index 1.54 is combined with another thin prism P2 made from glass of refractive index 1.72 to produce dispersion without deviation. The angle of the prismP2 is:

Q8

Two identical prisms 1 and 2, each with angles of 30o, 60o and 90o are placed in contact as shown in figure. A ray of light passes through

                                                     

The combination in the position of minimum deviation and suffers a deviation of 30o. if the prism 2 is removed, then the angle of deviation of the same ray is;

Q9

The angle of a prism is 30o. The rays incident at an angle of 60o at one refracting face suffer a deviation of 30o. Then the angle of emergence is:

Q10

 

A thin prism made of glass is dipped in water; then minimum deviation with respect to air by it will be: