Optics Answers

A plate of thickness t behaves as a half wave plate for a light of wavelength λ. ignoring variation in refractive indices with λ, if a light of 2λ is used then plate will behave as? (i know answer is quarter wave plate. But i don't know why... So please explain me)

When a single slit is replaced bydouble slit arrangement, the intensity of central maxima is increased by?

A grating of width 2cm is capable of resolving D1 and D2 lines of Sodium in the 3rd order. If the wavelength seperation of D1 and D2 lines is 6 Angstrom and average wavelenth of D1 and D2 lines is 5893 Angstrom. Then the number of lines on the grating?

When a sigle slit is replaced by the double slit arrangement, the intensity of central maximum is increased by?

what is convex lens

Bi-prism is kept 10 cm away from the slit illuminated by monochromatic light of wavelength 5896Å. the width of the fringes obtained on screen placed at a distance of 90 cm from the biprism is( 9*10^-4)m. What is the distance between two coherent sources.

What would happen if a mirror is used in place of a plane glass plate in the Newton’s rings experiment? Substantiate your answer by providing appropriate mathematical background

In a Young’s double slit experiment, the separation of eight bright fringes is 5mm when the wavelength used is 6200Å. The distance from the slits to the screen is 0.8m. Calculate the separation of the two slit.

Two plane plates of glass are in contact in one edge and are separated at a point 20 cm from that edge by a wire of diameter 0.05 mm. What will be the width between the consecutive dark interference fringes formed when light of wavelength 589nm falls normally on air film enclosed between the plates.

What is the power in dioptres of converging lens of focal lengths 2m, 0.5m, 50m