A pencil partly immersed in water in a glass tumbler appears to be displaced at the interface of air and water because:
A pencil partly immersed in water in a glass tumbler appears to be displaced at the interface of air and water because:
The correct option is B Light does not travel in the same direction in all media
When light rays travel from one medium to another, its direction changes because of the difference in refractive indices.
A ray of light coming from the lower end X of the pencil travels from water to the air and gets refracted away from normal as it travels from denser to rarer medium. Another ray coming from X will also get refracted in the same way. The two refracted rays, when produced backward, appear to meet at point Y as shown in the figure. Thus, a virtual image is formed at Y.
Hence, the pencil is actually straight but on immersing in water, it appears to be displaced at the interface of air and water.
Light does not travel in the same direction in all media
When light rays travel from one medium to another, its direction changes because of the difference in refractive indices.
A ray of light coming from the lower end X of the pencil travels from water to the air and gets refracted away from normal as it travels from denser to rarer medium. Another ray coming from X will also get refracted in the same way. The two refracted rays, when produced backward, appear to meet at point Y as shown in the figure. Thus, a virtual image is formed at Y.
Hence, the pencil is actually straight but on immersing in water, it appears to be displaced at the interface of air and water.
