ON22 P12 Q30 White Light Diffraction Fringes | Oct/Nov 2022 | Cambridge A Level 9702 Physics

[@machacooling]

Tysm misss❤

[@machacooling]

4:43 I still didn't understand the difference between option c and d 😢😭😭

[@somewhereonearth9]

VIBGYOR
here, violet has the least wavelength and red has the largest. You can roughly memorize it like with a difference of 50nm between each of the above colors. So:
Violet: 400nm, Indigo: 450nm, Blue: 500nm, Green: 550nm, Yellow: 600nm, Orange: 650nm, and Red 700nm
now, since n λ = d sin (theta), and n and d are constants, so λ ∝ theta. This means the larger the lambda, the large the angle.
So, by this we can say,
red having the larger (in the visible part) wavelength (700 nm) should have the larger angle
and violet should has the smaller (in the visible part) wavelength (500nm), should have the smaller angle
This means for one dot, red should be at the end, as to have a large angle (bec, larger lambda). Violet should be on the inner side, to account for it's lower angle (since it has smaller lambda)
this is shown in the option D
but it's opposite for C, the red is towards the inner side and violet on the outer side, which is wrong.
(all the other colour of the visible light will be in between)

[@fatimaarshad00]

@@somewhereonearth9omg thankyou so much😭