A parallel beam of light enters a clear plastic bead `2.50 cm` in diameter and index `1.44.` At what point beyond the bead are these rays brought to a focus?

A convex lens of diameter 8.0 cm is used to focus a parallel beam of light of wavelength 620 nm. If the light be focused at a distance of 20 cm from the lens, what would be the radius of the central bright spot formed ?

A convex lens of diameter 8.0 cm is used to focus a parallel beam of light of wavelength 620 nm. If the light be focused at a distance of 20 cm from the lens, what would be the radius of the central bright spot formed ?

A convex lens of diameter 8.0 cm is used to focus a parallel beam of light of wavelength 620 nm. If the light be focused at a distance of 20 cm from the lens, what would be the radius of the central bright spot formed ?

A sunshine recorder globe is a device that provides the information about climate and weather by recording the amount of sunshine for a given location. One such globe of diameter 20 cm and refractive index 1.5 is used for the purpose. A parallel beam of light enters the globe and is refracted by the spherical surface of the globe. Determine the position of the image of the rays formed.

Parallel beam of light of wavelength 420 nm is focused on a screen at a distance of 50 cm from the lens. What would be the radius of the central bright spot formed? Diameter of the lens is 10 cm.

A beam of light strikes a glass sphere of 20 cm diameter converging towards a point 40 cm behind the pole of the spherical surface.Fnd the position of the image,if the refractive index of glass is 1.5.

A glass sphere of refractive index 1.5 has a diameter of 0.2m. A parallel beam is incident on the sphere. Where is it brought to focus by the sphere ?

A parallel beam of light falls from vacuum on a surface enclosing a medium with refractive3 index n (Fig.) Find the shape of that surface, x(r ) if the beam is brought into focus at the point F at a distance f from the crest O . What is the maximum radius of a beam that can still be focussed ?

Two parallel beams of light P and Q are incident normally on a prism and the transmitted rays are brought to focus with the help of a convergent lens as shown in Fig. 2.23. If the intensities of the upper and lower beams immediately after transmission from face AC are 4I abd I, respectively, find the resultant intensity at the focus.

Two parallel beams of light P and Q are incident normally on a prism and the transmitted rays are brought to focus with the help of a convergent lens as shown in Fig. 2.23. If the intensities of the upper and lower beams immediately after transmission from face AC are 4I abd I, respectively, find the resultant intensity at the focus.