About Young's double slit experiment?
In a Young's double slits experiment, a monochromatic light source of wavelength 700nm is used and the separation of the slits is 0.1mm. If 15 bright fringes are observed, what is the angle subtended by those fringes at the centre of the double slit?
- 天同Lv 76 年前最愛解答
Since 15 fringes are produced, there are 7 fringes on each side of the central axis.
Hence, (0.1x10^-3).sin(theta) = 7 x (700x10^-9)
where angle(theta) is the angle subtended by the 7th fringe on the central axis.
thus, sin(theta) = 0.049
(theta) = 2.8°
Therefore, the angle subtended by the two extreme fringes at the centre of the double slit
= 2 x 2.8° = 5.6°
The answer is thus option B