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

Answer:

Hence the order of the bright fringe is 7.

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$\times$ sin(12.23°) = n$\times 550 \times 10^{-9}$

n = 7

Hence the order of the bright fringe is 7.