Question

Light of wavelength 600 nm is incident on a pair of slits. Fringes with a spacing of 4.0 mm are
formed on a screen.
What will be the fringe spacing when the wavelength of the light is changed to 400 nm and the
separation of the slits is doubled?
A 1.3 mm
B 3.0 mm
C 5.3 mm
D 12 mm

Answer 1

Is the answer A

Answer 2

yes

Answer 3

Do you know the double slit formula?

Answer 4

x=wavelength * d/a

Answer 5

d is distance from screen and a is slit separation

Answer 6

we only know x and wavelenght

Answer 7

I did it like this;
1.we are decreasing the wavelength and according to the formula x also decreases (directly proportional)
2. we are also doubling the slit separation which is inversely proportional to x, therefore x further deceases by a factor 2
It cant be D or C. It make sense that the answer should less than 3mm

Answer 8

ok thx

Answer 9

Did u understand

Answer 10

yes