When light passes from a rarer medium to a denser medium it:
Slows down
A denser medium has a higher refractive index, so light travels slower in it than in a rarer medium; hence light slows down on entering a denser medium.
Two convex lenses have focal lengths of 50 cm and 25 cm, respectively. If these two lenses are placed in contact, then the net power of this combination will be equal to
The refractive index of crown glass is close to 3/2. If the speed of light in air is c, then the speed of light in the crown glass will be close to
Tyndall effect is a phenomenon of