A beam of light consisting of red, green, and blue colours is incident on a right-angled prism. The refractive index of the material of the prism for the red, green, and blue wavelengths is 1.39, 1.44, and 1.47 respectively. 
  
The prism will:

1. separate the blue colour part from the red and
    green colour

2. separate all the three colours from one another

3. not separate the three colours at all 

4. separate the red color part from the green and
    blue colours

The angle of a prism is 'A'. One of its refracting surfaces is silvered. Light rays falling at an angle of incidence 2A on the first surface returns back through the same path after suffering reflection at the silvered surface. The refractive index μ, of the prism, is :

1. 2sinA

2. 2cosA

3. $\frac{1}{2}$cosA

4. tanA

A ray of light is incident at an angle of incidence, i, on one face of a prism of angle A (assumed to be small) and emerges normally from the opposite face. If the refractive index of the prism is $\mu$, the angle of incidence i, is nearly equal to

1. $\mu$A

2. $\frac{\mu A}{2}$

3. $A/\mu$

4. $A/2\mu$

For the angle of minimum deviation of a prism to be equal to its refracting angle, the prism must be made of a material whose refractive index -

1.  lies between 2 and $\sqrt{2}$

2.  is less than 1 

3.  is greater than 2 

4.  lies between $\sqrt{2}$ and 1

A thin prism of angle 15º made of glass of refractive index ${\mathrm{\mu }}_1$ = 1.5 is combined with another prism of glass of refractive index ${\mathrm{\mu }}_2$ = 1.75. The combination of the prism produced dispersion without deviation. The angle of the second prism should be :
1. 5º
2. 7º
3. 10º
4. 12º

A ray of light is incident on a 60º prism at the minimum deviation position. The angle of refraction at the first face (i.e. incident face) of the prism is:

1. 30º

2. 45º

3. 60º

4. zero