Question

give reason a straw appears bent in water​

Answer 1

When we look at a straw in a glass of water, light from the top of the straw travels staight to the eye. Light from the part that's underwater is refracted when it goes from the water to the air; it changes direction.

Answer 2

this is due to refraction of light or bending of light. this happens when light from a medium enters another medium.