Answer:
273 dots/inch
Explanation:
We are given:
•Average wavelength = 555mm
•d = 3.5mm
• distance = 48cm
Let's use the Reyleigh formula:
∅ = 1.22[tex]\frac{wavelength}{D} [/tex]
Substituting figures in the formula, we have:
[tex] \frac{(1.22)(555mm[\frac{10^-9m}{1mm}])}{3.5mm[\frac{10^-^3}{1mm}]} [/tex]
[tex] 1.935*10^-^4 rad[/tex]
From the formula above, we get:
∅ = x/d
where x is distance btw dots and pupil
Solving for x we get:
x =∅d
[tex]x = (1.935*10^-^4 rad)(48) [/tex]
[tex] x = 9.3*10^-^3cm[/tex]
To calculate dots per inch(dpi), we use:
[tex]dpi = \frac{2.54cm/inch}{x}[/tex]
We already know 1 inch =2.54cm
Therefore,
[tex]dpi = \frac{2.54cm/inch}{9.3*10^-^3cm}[/tex]
273 dots/inch