Monochromatic light with wavelength \(\lambda\) is incident normally on a single slit of width \(a\). The resulting diffraction pattern is observed on a screen far from the slit, with the first dark fringe occurring at an angle \(\theta_1 = 0.30^\circ\). The slit width is then adjusted to \(a' = \dfrac{a}{2}\) while keeping all other parameters constant. How does the width of the central bright maximum change, and what is the new angle \(\theta_1'\) to the first dark fringe?