3 Place an object on the table. Look at the object through the transparent glass slab. You will observe that it will appear closer to you. Draw a ray diagram to show the passage of light ray in this situation. `(AS_(5))`

Describe the activity to show that the colours of white light splitted by a glass prism can be recombined to get white light by another identical glass prism. Also draw ray diagram to show the recombination of the spectrum of white light.

Explain the refraction of light through a glass slab with a neat ray diagram (AS_(5))

The redius of curvature of the convex face of a plano-convex lens is 12cm and its refractive index is 1.5. a. Find the focal length of this lens. The plane surface of the lens is now silvered. b. At what distance form the lans will parallel rays incident on the convex face converge? c. Sketch the ray diagram to locate the image, when a point object is places on the axis 20cm from the lens. d. Calculate the image distance when the object is placed as in (c).

Find the lateral shift of a light ray while it passws through a parallel glass slab of thickness 10 cm places in air. The angle of incidence in air is 60^(@) and the angle of refraction in glass is 45^(@) .

A transparent thin film of uniform thickness and refractive index n_(1) =1.4 is coated on the convex spherical surface of radius R at one end of a long solid glass cylinder of refractive index n_(2) =1.5 , as shown in the figure. Rays of light parallel to the axis of the cylinder traversing through the film from air to glass get focused at distance f_(1) from the film, while rays of light traversing from glass to air get focused at distance f_(2) from the film, Then

An object is placed 21 cm in fron of a concave mirror of radis of curvature 20 cm.A glass slab of thicknes 3 cm and refractive index 1.5 is palced close to the mirror in the space between the object and the mirror. Find the position of the final image fromed. The distance of the nearer surface of the slab from the mirror is 10 cm.

As shown in figure waves with identical wavelengths and amplitudes and which are intially in phase travel through difference media. Ray 1 travels through air and Ray 2 through a transparent medium for equal length L, in four different situations. Rays reach a common point on the screen. The number of wavelengths in length L is N_(2) for Ray 2 and N_(1) for Ray 1. In the following table, values of N_(1) and N_(2) are given for all four situations. The order or the situations according to the intensity of the light at the common point in descending order is Situations 1 2 3 4 N_(1) 2.75 1.80 3.00 3.25 N_(2) 2.75 2.80 3.25 4.00

A quarter cylinder of radius R and refractive index 1.5 is placed on a table.A point object P is kept at a distance of mR from it. Find the value of m for whicha ray from P will emerge parallel to the table as shown in the figure.

To demonstrate the process of thermoelectric production with a model. Apparatus and materials: Pressure cooker, pipe, tennis ball, metal sheet, dynamo, bulb. Procedure : rarr Take a table-tennis ball and make three slits into it. rarr Put semicircular fins cut out of a metal sheet into these slits. rarr Pivot the tennis ball on an axle through its centre with a straight metal wire fixed to a rigid support. Ensure that the tennis ball rotates freely about the axle. rarr Now connect a cycle dynamo to this. rarr Connect a bulb in series. rarr Direct a jet of water or steam produced in a pressure cooker at the fins. Note down your observation. Observation : The bulb gets lighted. Which energy conversion do you think is taking place in this model ?

The ciliary muscles of eye control the curvature of the lens in the eye and hence can alter the effective focal length of the system. When the muscles are fully relaxed, the focal length is maximum. When the muscles are strained, the curvature of lens increases. That means radius of curvature decreases and focal length decreases. For a clear vision, the image must be on the retina. The image distance is therefore fixed for clear vision and it equals the distance of retina from eye lens. It is about 2.5cm for a grown up person. A perosn can theoretically have clear vision of an object situated at any large distance from the eye. The smallest distance at which a person can clearly see is related to minimum possible focal length. The ciliary muscles are most strained in this position. For an average grown up person, minimum distance of the object should be around 25cm. A person suffering from eye defects uses spectacles (eye glass). The function of lens of spectacles is to form the image of the objects within the range in which the person can see clearly. The image o the spectacle lens becomes object for the eye lens and whose image is formed on the retina. The number of spectacle lens used for th eremedy of eye defect is decided by the power fo the lens required and the number of spectacle lens is equal to the numerical value of the power of lens with sign. For example, if power of the lens required is +3D (converging lens of focal length 100//3cm ), then number of lens will be +3 . For all the calculations required, you can use the lens formula and lensmaker's formula. Assume that the eye lens is equiconvex lens. Neglect the distance between the eye lens and the spectacle lens. Q. Maximum focal length of a eye lens of a normal person is