Duduli

When some electromagnetic wave is incident on a scatterer atom, whose size is comparable to wave length of wave, then due to the electric vector of the incident wave the atom starts oscillating.This oscillating atom(acting as small dipole) itself emitts radiations. But the reemission of e.m. wave by the oscillating dipole is such that it emitts e.m. waves in all directions except in the direction of oscillation.This fact can be used for polarization of light.

Photoelasticity is an experimental method to determine stress distribution in various engineering components.The method is mostly used in cases where mathematical methods become quite cumbersome (difficult). Photoelasticity is especially useful for the study of objects with irregular boundaries and stress concentrations, such as pieces of machinery with notches or curves, structural components with slits or holes, and materials with cracks.

Apparent depth is the virtual depth that is observed as a result of the refraction of light.The apparent depth depends upon the refractive index of the medium.In case of viewing other than vertically, the position of the image changes with the angle, which the line of vision makes with the surface of separation of the two media. As the angle increases, the apparent depth decreases.Also, the object appears curved when viewed obliquely through the refracting medium. Look at the following figure

Electrical power transmission through any conductor is always accompanied by energy loss I²R, where I is the current and R is the resistance of the conductor. If superconductors are used, the losses will be eliminated and power transmission can be done at a lower voltage level.

With hydrogen atom as the positive end of the dipole, if bonds arise as a result of electrostatic attraction between atoms, it is known as hydrogen bonding.