In a single-slit diffraction experiment,the angular width of the central maximum is 0.16°.The width of the slit is then doubled as is the distance to the screen.What is the resulting angular width of the central maximum?
A)0.64°
B)0.080°
C)0.32°
D)0.16°

Question

Quizplus · Accepted Answer

The angular width of the central maximum is given by: 
θ = λ/d
where λ is the wavelength of the light and d is the width of the slit.
When the slit width is doubled, the angular width of the central maximum becomes:
θ' = λ/2d
Similarly, when the distance to the screen is doubled, the angular width becomes:
θ'' = λ/4d
Since we are only doubling the slit width and distance, the wavelength of the light remains the same. Therefore, we can use the ratio of the new and old angular widths to find the answer:
θ''/θ = (λ/4d)/(λ/d) = 1/4
Therefore, the new angular width of the central maximum is:
θ'' = (1/4)θ = (1/4)(0.16°) = 0.04° = 0.080°
So the best choice is B.

In a Single-Slit Diffraction Experiment,the Angular Width of the Central