Question

Monochromatic light of wavelength 550 no passes through a diffraction grating that has 55000 lines/m. A bright line appears on the screen at an angle of 12.23o from the central bright fringe. What is the order of this bright line?

A. 5
B. 6
C. 7
D. 8

Answer 1

Hence the order of the bright fringe is 7.

Step-by-step explanation:

Diffraction can be defined as the deviation from rectilinear propagation and diffraction grating is used to measuring the wavelength of light using a spectrometer.

We have the formula d sin∅ = n l

We have to find the value of n in this equation and all other values are given.

Here d = 55000 lines

∅ = 12.23°

Wavelength , l = 550 nanometer

n is the order of the bright line.

Substitute these values in the given equation,

55000
`*` sin(12.23°) = n
`* 550 * 10^(-9)`

n = 7

Hence the order of the bright fringe is 7.