Skip to main content

Uses of Concave Mirror

Uses of Concave Mirror :
(i) It is used as a shaving mirror because when it is placed close to the face, it forms a large image.
(ii) It is used in solar heating devices like solar cooker, because it converges Sun’s rays over a small area to produce high temperature.
(iii) It is used for security checking purposes.

Comments

Popular posts from this blog

Limitations of Mendeleev's Periodic Table

Mendeleev arranged 63 elements known at that time in the periodic table. According to Mendeleev “the properties of the elements are a periodic function of their atomic masses.” The table consists of eight vertical column called ‘groups’ and horizontal rows called ‘periods’ Limitations of mendeleev’s classification : (i) He could not assign a correct position of hydrogen in his periodic table, as the properties of hydrogen resembles both with alkali metals as well as with halogens. (ii) The isotopes of the same element will be given different position if atomic number is taken as basis, which will disturb the symmetry of the periodic table. (iii) The atomic masses do not increases in a regular manner in going from one elements to the next. So it was not possible to predict how many elements could be discovered between two elements.

Some topics of Physics

13. Refraction of Light :  The bending of ray of light when it passes from one medium to another is called refraction of light. Laws of Refraction : (i) The incident ray, the refracted ray and the normal at the point of incidence all lie in the same plane. (ii) When a ray of light undergoes refraction then the ratio of sine of angle of incidence to the sine of angle of refraction is constant. 14. The Refractive Index :  The refractive index of medium 2 with respect to medium is given by the ratio of the speed of light in medium 1 and the speed of light in medium 2. This is usually represented by the symbol n 21 . This can be expressed in an equation form as