Complete the path of the monochromatic light ray AB incident on the surface PQ of the equilateral glass prism PQR till it emerges out of the prism due to refraction.

The wave lengths for the light of red and blue colours are nearly 7.8 x 10^-7 m and 4.8 x 10^-7 m respectively.

(i) Which colour has the greater speed in a vacuum?

(ii) Which colour has a greater speed in glass?

Draw a graph between displacement from mean position and time for a body executing free vibration in a vacuum.

Where should an object be placed in front of a convex lens in order to get:

(i) an enlarged real image,

(ii) enlarged virtual image?