Question

A 550 lines/mm diffraction grating is illuminated by light of wavelength 500 nm . Part A How many bright fringes are seen on a 3.8-m-wide screen located 2.2 m behind the grating?

Answer 1

To determine the number of bright fringes seen on the screen, we can use the equation Ay = mλL/d. Plugging in the given values, we find that there are 0.000345 bright fringes on the screen.

Step-by-step explanation:

To determine the number of bright fringes seen on the screen, we use the formula: Ay = mλL/d, where Ay is the distance between fringes, m is the order of the fringe, λ is the wavelength of light, L is the distance between the grating and the screen, and d is the distance between the grating lines.

In this case, we have 550 lines/mm, so d = 1/550 mm. The wavelength of light is 500 nm. The screen is located 2.2 m behind the grating.

Plugging these values into the formula, we get: Ay = (2.2 m)(500 nm)/(1/550 mm) = 1.1 x 10^4 m. Since the screen is 3.8 m wide, we can divide the width of the screen by the distance between fringes to find the number of bright fringes: Number of fringes = 3.8 m / (1.1 x 10^4 m) = 0.000345 fringes.