A Level Physics Practice Exam 2025 - Free A Level Physics Practice Questions and Study Guide

In Young's double slit experiment, "w" typically refers to the fringe spacing, which is the distance between adjacent bright or dark fringes on a screen due to the interference of light waves. In this context, fringe spacing is influenced by factors such as the wavelength of the light used and the geometry of the setup (specifically, the distance between the slits and the screen, as well as the separation between the slits).

This concept arises from the formula that relates fringe spacing to wavelength and other parameters: fringe spacing is directly proportional to the wavelength of the light and inversely proportional to the slit separation and the distance to the screen. Therefore, understanding "w" as fringe spacing is essential for analyzing the pattern observed in the experiment.

Other choices, such as the wavelength of light or distance between the light source and the screen, have their own significance in the experiment, but they do not precisely represent what "w" stands for in this specific context.