## Physics: Principles with Applications (7th Edition)

Equation 24-2a, $sin \theta = \frac{m \lambda}{d}$, predicts the location of the maxima for integer values of m. Increasing the wavelength $\lambda$ (red light has a long wavelength) and decreasing the slit spacing d will increase the angle $\theta$ at which each maximum is seen, increasing the spacing of the fringes.