What should be the angle of incidence of a light ray incident through air on the boundary separating air from water so that the angle of refraction is 30 °? (refractive index of air is 1 and that of water is 1.32)

What are similarities and differences of reflection, refraction, diffraction and absorption?

The built in flash in a compact camera is usally capable of giving correct exsposure for distance up to how many meters?

Consider a production line with five stations. station 1 can produce a unit in 9 minutes. station 2 can produce a unit in 10 minutes. station 3 has two identical machines, each of which can process a unit in 12 minutes (each unit only needs to be processed on one of the two machines. station 4 can produce a unit in 5 minutes. station 5 can produce a unit in 8 minutes. which station is the bottleneck station?