The 546.1 nm line in mercury is measured at an angle of 73.2° in the third-order spectrum of a diffraction grating. Calculate the number of lines per centimeter for the grating.

There are 5847.95 lines per cm for the grating.

Explanation:

Given that,

Wavelength of mercury line,

Angle in the third order spectrum,

Using the grating equation, we get :

Here, m = 3

Let there are N lines for the grating. So,

So, there are 5847.95 lines per cm for the grating.

answer(20) psi;