A Level Physics Practice Exam

In the equation d * sin(θ) = n * λ, what does 'd' represent?

1. Path difference

2. Distance between slits

3. Wavelength of light

4. Angle of incidence

The correct answer is: Distance between slits

In the equation \( d \cdot \sin(θ) = n \cdot λ\), the term 'd' specifically represents the distance between the slits in a double-slit experiment or diffraction grating setup. This distance is crucial because it directly affects the interference pattern observed on a screen. As the distance between the slits increases, the spacing of the fringes in the interference pattern changes, which can be analyzed using this equation. The equation describes how light waves interact with multiple openings, leading to constructive and destructive interference. In this context, 'n' represents the order of the interference (which can be a whole number), and 'λ' is the wavelength of the light used. Understanding 'd' as the distance between slits is pivotal in analyzing and solving problems related to wave interference and diffraction phenomena in physics.