A light ray of wavelength X is passing through a pin hole of diameter D and the effect is observed on a screen placed at a distance L from the pin hole. The approximation of geometrical optics are applicable if

Light of wavelength 620 nm goes through a pinhole of diameter 0.1 mm. Screen is placed at a distance 5 m from the hole. What will be the radius of the central bright spot formed ?

A light beam of wavelength 800 nm passes through a single slit and projected on a screen kept at 5m away from the slit. What should be the slit width for the ray optics approximation to be valid ?

Light travels in a straight line. This principle is illustrated in a pinhole camera. In this simple device the image of an object is formed on a photographic plate by light passing through a small hole. In one experiment, 5 cm high image of a tree was obtained on a photo plate placed at a distance of 15 cm from the pin hole. Actual height of the tree is 20 m. (a) Find the distance of the pinhole from the tree. (b) How is the size of image affected if the photo plate is moved away from the pinhole? (c) What will happen if a large hole is made in place of a pin hole?

Radiowaves of wavelength 3m are incident on a rectangular hole of width 5m . A screen is placed at a distance 200m from the hole. The width of the central is 100bm . Then find b .

Radiowaves of wavelength 3m are incident on a rectangular hole of width 5m . A screen is placed at a distance 200m from the hole. The width of the central is 100bm . Then find b .

Light of wavelength lambda is incident on slit of width d. The resulting diffraction pattern is observed on a screen placed at distance D. The linear width of central maximum is equal to width of the slit then D = .......

Light of wavelength 5000 A^(0) is incident on a slit. The first minimum of the diffraction pattern is observed to lie at a distance of 5 mm from the central maximum on a screen placed at a distance of 3 m from the slit. Then the width of the slit is