Respuesta :
Answer:
Explanation:
slit separation d = .3 x 10⁻³ m
screen distance D = 4.35 m
fringe width = 6.4 x 10⁻² / 9
= .711 x 10⁻² m
a ) Interference pattern on the screen is created due to interference of two light waves coming from two slits and falling in screen . When they fall on different points on the screen they travel different distance . This is called path difference . When their path difference is equal to their wave length or its integral multiple , they reinforce each other and at that point the brightness increases . On the other hand when at a point the path difference is equal to odd multiple of half wavelength , they kill or destroy each other and darkness is found at that point . In this way dark band and bright band appear on the screen . This is called interference pattern .
b )
Fringe width = λ D / d
Putting the values
.711 x 10⁻² = λ x 4.35 / 0.3 x 10⁻³
λ = .049 x 10⁻⁵
= 490 x 10⁻⁹
= 490 nm
The colour of this wavelength will be blue .
