Write 'true' or 'false' for the following


1. A ray of light striking normally on another optical medium does not sufferrefraction.
2. The angle of incidence is always smaller than angle of refraction when a ray travels from air to glass.
3. The ratio between velocity of light in vacuum
to velocity of light in air is called refractive index.
4. A ray travelling from glass to air, bends away from the normal.
5. A pencil held obliquely in water appears bent and longer.​