Choose the correct mirror image of the figure:
    

1.		2.
3.		4.

An air bubble in a glass slab with refractive index 1.5 (near-normal incidence) is 5 cm deep when viewed from one surface and 3 cm deep when viewed from the opposite face. The thickness (in cm) of the slab is:

If the focal length of the objective lens is increased, then magnifying power of:

A concave mirror gives an image three times as large as the object placed at a distance of 20 cm from it. For the image to be real, the focal length should be:

A mark on the surface of sphere (µ = 3/2) is viewed from a diametrically opposite position. It appears to be at a distance \(15~\mathrm{cm}\) from its actual position. The radius of sphere is:
1. 15 cm
2. 5 cm
3. 7.5 cm
4. 2.5 cm

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

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:
       

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

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:
        

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