Cross-section view of a prism is the equilateral triangle \( ABC \) shown in the figure. The minimum deviation is observed using this prism when the angle of incidence is equal to the prism angle. The time taken by light to travel from \( P \) (midpoint of \( BC \)) to \( A \) is _______ \( \times 10^{-10} \, \text{s} \). (Given, speed of light in vacuum \( = 3 \times 10^{8} \, \text{m/s} \) and \( \cos 30^{\circ} = \frac{\sqrt{3}}{2} \))
