Two thin similar convex glass are joined together front to front, with its rear portion silvered such that a sharp image is formed `0.2m` for an object at infinity. When the air between the glass pieces is replaced by water `(mu=4/3),` find the position of image.

Two thin similar watch glass pieces are joimed together,front to front ,woth near convex portion silvered and the combination of glass pieces is placed at a distanc e a=60cm from a screen.A small object is placed normal to the optical axis of the combination such that its two water mu=4//3 ,calcuated the distance through,which the object must eb displayed so that a sharp image is again formed on the screen.

A small object is placed 20 cm in front of a block of glass 10 cm thick and its farther side silvered. The image is formed 22 cm behind the silvered face. Find the refractive index of glass.

A thin lens, made of glass of refractive index 3//2, produces a real and magnified image of an object in air. If the whole system, maintaing the same distance between the object and the lens, is immersed in water (RI=4//3), then the image formed will be

The focal length of a convex lens of glass (mu = 1.5) in air is 30 cm. Find its focal length when the lens is placed in water (mu = 4//3) .

The convex surface of a thin concave-convex lens of glass of refractive index 1.5 has a radius of curvature 20 cm. The concave surface has a radius of curvature 60 cm. The convex side is silvered and placed on a horizontal surface as shown in figure. (a) Where should a pin be placed on the axis so that its image is formed at the same place ? (b) If the concave part is filled with water (mu = 4/3), find the distance through which the pin should be moved so that the image of the pin again coincides with the pin.

A thin converging lens is placed between an object and a screen whose position are fixed. There are two positions of the lens at which the sharp image of the object is formed on the screen. Find the transverse dimension of the object if at one position of the lens the image dimension equal h' = 2.0 mm and at the other, h'' = 4.5 mm .

An object is placed 20cm in front of a block of glass 10cm thick having its farther side silvered. The image is formed 23.2cm behind the silvered face. The refractive index of glass is

4 A thin liquid convex lens is formed in glass. Refractive index of liquid 4/3 is and that of glass is 3/2 If 'f' is the focal length of the liquid lens in air its focal length and nature in the glass is

A thin convergent lens is placed between an object and a screen whose positions are fixed. There are two positions of a lens at which sharp image of the object is formed on the screen. If the size of the images in the two cases are 2 mm and 4.5 mm then the size of the object should be:-