Why does light refract when it encounters the glass in a lens?
a)
because it speeds up, which causes it to bend
b)
because it slows down, which causes it to bend
c)
because it hits a dense medium, which causes it to bounce off
d)
because it gets absorbed, which causes it to lessen in intensity

The correct answer to this question is B) Because it slows down, which causes it to bend  .

EXPLANATION:

Before going to answer this question, first we have to understand refraction.

Refraction is the optical phenomenon in which light ray coming from one medium will bend towards or away from the normal at the point of incidence of the refracting surface between two media.

It is due to the fact that velocity of light is not always constant in every medium. The velocity of light is minimum in optical denser medium, and maximum in optical rarer medium.

When light comes from optical rarer medium to optical denser medium, the light will bend towards the normal at the point of incidence of the refracting surface. The light will bend away from the normal if light will move from optical denser medium to optical rarer medium.

As per the question, the light is refracted due to a glass lens. The lens is optically denser as compared to air. Hence, the velocity of light will slow down inside the lens.

Hence, the correct answer to the question is that velocity of light slows down in a glass lens which causes the light to bend.

if the thermos has a vacuum innner, then heat through conv currents and conduction are reduced = vacuum flask

come closer and become far apart and become steam/gas