In the List-I, four optical effects are mentioned. The physical...

The colorful sky in the north polar region, known as Aurora Borealis, is caused by the emission of radiation from oxygen and nitrogen atoms in the upper atmosphere when they are excited by charged particles from the solar wind. Thus, P $\rightarrow$ 5.

Sunlight scattered by molecules in the atmosphere becomes partially polarized in a direction perpendicular to the incident light. Thus, Q $\rightarrow$ 4.

A rainbow is formed due to the dispersion of sunlight and its internal reflection by water droplets in the atmosphere. Thus, R $\rightarrow$ 1.

Dark and bright fringes are the characteristic patterns formed due to the superposition of light waves, which occurs in phenomena like interference and diffraction. Thus, S $\rightarrow$ 3.

The correct matching is P $\rightarrow$ 5, Q $\rightarrow$ 4, R $\rightarrow$ 1, S $\rightarrow$ 3.

Answer: P$\rightarrow$5, Q$\rightarrow$4, R$\rightarrow$1, S$\rightarrow$3