Exercise-1

In the displacement method, a convex lens is placed in between an object and a screen. If one of  the magnification is $3$ and the displacement of the lens between the two positions is $24\mathrm{cm}$, then the focal length of the lens is:

A beam of light consisting of red, green and blue and is incident on a right angled prism. The refractive index of the material of the prism for the above red, green and blue wavelengths are $1.39,1.44$ and $1.47$ respectively. The prism will-

A ray of light is incident normally ao the refracting face of the prism of refracting angle $\mathrm{A}$. The ray of light comes out at grazing emergence. If one half of the prism(shaded position) is knocked off, the same ray will-

A horizontal ray of light passes through a prism of index $1.50$ and apex angle $4°$ and then strikes a vertical mirror,as shown in the figure. Through what angle must the mirror be rotated if after reflection the ray. $\mathrm{s}$ to be horizontal?

The curve of angle of incidence versus angle of deviation shown has been plotted for prism. The value of refractive index of the prism used is:

A beam of monochromatic light is incident at $\mathrm{i}=50°$ on one face of an equilateral prism. The angle of emergence is $40°$, then the angle of minimum deviation is:

A parallel beam of white light falls on a convex lens. Images of blue, red and green light are formed on other side of the lens at distances $\mathrm{x},\mathrm{y}$ and $\mathrm{z}$ respectively from the pole of the lens. Then:

Which of the following quantities related to a lens does not depend on the wavelength of the incident light?