Blue green light with wavelength of 500 nm is incident from the left on a single

Question

Blue green light with wavelength of 500 nm is incident from the left on a single slit with a slit width of 20 Micrometers. At what distance y from the central maxima will you find the second order minima for the slit if the vewing screen is 5 meters from the slit?

I know I need to use the following equation:

where m= 2 (the order)

lambda = 500 nm

I am having a hard time figuring out what a is supposed to be for the equation. I know I am to rearrange the formula and solve for theta so that the following equation shown above looks as follows:

Can someone please tell me how I find the a value I would greatly appreciate it thanks!!

Explanation / Answer

Given,
Wavelength, = 500 * 10^-9 m
Slit Width, a = 20 * 10^-6 m
Distance btw Screen & Slit, L = 5.0 m

We know,
a sin() = m*
tan() = y / L

Since the angle () is very small, Thus, tan() » sin()

Therefore,
a*y/L = m*
y = (L*m*)/a

For second order minima , m = 2
Substituting Values -
y =  (5*2*500*10^-9)/(20*10^-6)
y = 0.25 m

Answer , Y = 0.25 m

Between in Your Soln also a is the Slit Width = 20 * 10^-6 m.

Related Questions

Navigate

• Browse (All)
• Browse B
• Subjects