In a Young's double-slit interference apparatus,the distance from the slits to the screen is tripled.The distance between adjacent light and dark fringes changes by a factor of:
A)1/3.
B)1.
C)3.
D)1/9.

Question

Quizplus · Accepted Answer

The distance between adjacent fringes in Young's double-slit interference pattern depends on the wavelength of light used and the distance between the slits and the screen (known as the "path difference"). The path difference is given by d sin θ, where d is the distance between the slits and θ is the angle between the screen and the line connecting the slits and the point on the screen. When the distance from the slits to the screen is tripled, the path difference also triples. Since the distance between adjacent fringes is directly proportional to the path difference, the distance between adjacent fringes also triples. Therefore, the correct answer is C.

In a Young's Double-Slit Interference Apparatus,the Distance from the Slits