$A$ white screen illuminated by green and red light appears to be

Which colour of the light has the longest wavelength?

Fraunhofer lines are produced by the absorption of light in

$A$ screen receives $3 \ W$ of radiant flux of wavelength $6000 \ \mathring{A}.$ One lumen is equivalent to $1.5 \times 10^{-3} \ W$ of monochromatic light of wavelength $5550 \ \mathring{A}.$ If the relative luminosity for $6000 \ \mathring{A}$ is $0.685$ while that for $5550 \ \mathring{A}$ is $1.00,$ then the luminous flux of the source is:

Compare and contrast the interference and diffraction.

In interference and diffraction, the light energy is redistributed. If it reduces in one region, producing a dark fringe, it increases in another region, producing a bright fringe. Statement $A$: As there is no gain or loss of energy, these phenomena are consistent with the principle of conservation of energy. Statement $B$: Diffraction and interference are characteristics exhibited only by light waves. Choose the correct answer from the options given below: