When a light ray passes through from air to water with a non-zero angle the ray will be

When a light ray travels from one medium to another with a non-zero angle of incidence, it undergoes refraction due to a change in speed [3]. According to the principles of geometrical optics, when light moves from an optically rarer medium (lower refractive index) to an optically denser medium (higher refractive index), the ray bends towards the normal [3]. Air is considered an optically rarer medium with a refractive index of approximately 1.0, while water is an optically denser medium with a higher refractive index [3]. Consequently, as the light ray enters the water from the air at an oblique angle, its speed decreases, causing the refracted ray to deviate from its original path and bend towards the normal line. This behavior is quantitatively described by Snell's Law, which relates the indices of refraction to the sines of the angles of incidence and refraction [2].

Sources

1. [3] https://www.ncbi.nlm.nih.gov/books/NBK594230/
2. [1] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Activity 9.10 > p. 147
3. [2] Science , class X (NCERT 2025 ed.) > Chapter 9: Light – Reflection and Refraction > Activity 9.10 > p. 148