Consider sunlight incident on a slit of width \({ 10 }^{ 4 }\)A. The image seen through the slit shall darkness as observed through the polaroid

In a young's double slit experiment, the source is white light. One of the holes is covered by a red filter and another by a blue filter. In this case

For light diverging from a point source

What is range of vision?

A person looking at a mesh of crossed wires is able to see the vertical wires more distinctly than the horizontal wires. Why? How can it be corrected?

A myopic person prefers to remove his spectacles while reading a book. Why?

Through a simple microscope, an object is seen in red light first and then in violet light.In which case is magnifying power more?

What is the essential difference between fluorescence and phosphorescence?

In the normal adjustment of an astronomical telescope, the distance between the objective lens and the eye lens is 10 sm. The magnifying power of the telescope is 4. Calculate the focal lengths of objective and eye lens.

A breaker is filled with water to a height of 12.5 cm. The apparent depth of a needle lying at the bottom of the beaker is measured by a microscope to be 9.4 cm. What is the refractive index of water ? If  water is If water is replaced by a liquid of refractive index 1.63 upto the same height, by what distance would the microscope have to be moved to focus on the needle again ?

Show that at polarising angle, the reflected and refracted beams of light are at \({ 90 }^{ \circ }\) to each other.

When an object is placed at a distance of 60 cm from a convex spherical mirror, the magnification produced is 1/2. Where should the object be placed to get a magnification of 1/3?