In the following diagram, what is the distance x if the radius of curvature is R = 15 cm?

     

1. 30 cm

2. 20 cm

3. 15 cm 

4. 10 cm 

In the diagram shown below, the image of the point object O is formed at \(l\) by the convex lens of focal length 20 cm, where \(F_1\) and \(F_2\) are foci of the lens. The value of \(x'\) is:
        

A glass slab is placed with the right-angled prism as shown in the figure. The possible value of \(\theta\) such that light incident normally on the prism does not pass through the glass slab is:

A graph is plotted between the angle of deviation \(\delta\) in a triangular prism and the angle of incidence as shown in the figure. Refracting angle of the prism is:

Three identical thin convex lenses are kept as shown in the figure. A ray passing through the lens is shown. The focal length of each lens is:

The following diagram shows a glass sphere of radius \(10~\mathrm{cm}\) with a paraxial incident ray. The refractive index of the material of the glass is:

     
1. 2
2. 1.5
3. 1.75
4. 1.3

An astronomical telescope has angular magnification of 20 in its normal adjustment. Focal length of eyepiece is 4 cm. Distance between objective and eyepiece is:

1. 80 cm

2. 84 cm

3. 76 cm

4. 90 cm

If the space between two convex lenses of glass in the combination shown in the figure below is filled with water, then:
          

Focal lengths of objective and eyepiece of a compound microscope are 2 cm and 6.25 cm respectively. An object AB is placed at a distance of 2.5 cm from the objective which forms the image A'B' as shown in the figure. Maximum magnifying power in this case, will be:
       

A concave lens of focal length 25 cm produces an image $\frac{1}{10}\mathrm{th}$ the size of the object. The distance of the object from the lens is:

1. 225 cm

2. 250 cm 

3. 150 cm 

4. 175 cm