Question

nucleus and yellow light of wavelength 150 and passes through two slits separated by 0.1 M the interference pattern is observed on screen 0.5 mm behind the streets find the distance between bright fringes of order 1 and 3 ​

Answer 1

Given that,

Wavelength = 150 nm

Slits separation d= 0.1 m

Distance between screen and slit D= 0.5 mm

We need to calculate the distance for one order

Using formula of distance

$y_{1}=\dfrac{m\lambda D}{d}$

Where, $\lambda$ = wavelength

d = Slits separation

D = distance between screen and slit

Put the value into the formula

$y_{1}=\dfrac{1\times150\times10^{-9}\times0.5\times10^{-3}}{0.1}$

$y_{1}=7.5-10^{-10}\ m$

We need to calculate the distance for one order

Using formula of distance

$y_{3}=\dfrac{m\lambda D}{d}$

Put the value into the formula

$y_{3}=\dfrac{3\times150\times10^{-9}\times0.5\times10^{-3}}{0.1}$

$y_{3}=2.25-10^{-9}\ m$

$y_{3}=22.5\times10^{-10}\ m$

We need to calculate the distance between bright fringes

Using formula of distance

$\Delta y=y_{3}-y_{1}$

Put the value into the formula

$\Delta y=22.5-10^{-10}-7.5-10^{-10}$

$\Delta y=14.9\ m$

$\Delta y=0.0149\ mm$

Hence, The distance between bright fringes of order 1 and 3 is 0.0149 mm.