Notebookerrs Blog

Reflection of light is a phenomenon of bouncing back of light after hitting a surface. When a ray of light falls on a surface some of the light reflects, some passes through the surface (refract) and some gets absorbed by the surface. As of now we are talking about reflection only. When the surface is smooth like mirror or polished metal surface the kind of reflection takes place is called Specular Reflection. 2 things are to be noted here The incident ray, the reflected ray and the normal ( perpendicular ) to the surface lie on the same plane The angle of incidence and the angle of reflection are always equal They are called laws of reflection of light. But if the surface is not smooth like, wall or paper or screen the incident rays reflect in different directions and the light diffuse in the surrounding. This type of reflection is called Diffuse Reflection. Mirror Vs Screen In Mirror Specular Reflection takes place and the reflected ray of ligh...

Incandescent lamp is very simple in construction and principle. Electrons when flow through a resistance generates heat. More the resistance more the heat. In this lamp a high resistance tungsten filament is used. When a voltage is applied the tungsten filament gets red hot and glows. The problem is when it glows it causes a slow evaporation of the tungsten filament. The evaporated tungsten deposits on the inner side of the glass bulb and blackens the bulb. This dims the glow of the bulb, and also there is a loss of material from the filament. Eventually the filament weakens and breaks. To solve this problem this bulb is modified a little bit. Halogen materials are chemicals elements that are very active to react with metal and form salt. Iodine and Bromine are halogen. In a halogen lamp a little bit of Bromine or Iodine is introduced inside the bulb. When the tungsten evaporates it reacts with the Bromine/Iodine and form salt. And at higher temperature the sal...

Street Lamps Street lights are bright yellow in color most of places, the reason behind this is the type of lamps used in streets, Sodium Vapour Lamps How Sodium Vapour Lamps work Sodium Vapour lamps are made of a glass tube filled with inert gas like helium and argon and a small amount of sodium. Two electrodes are placed on the ends of the tube. When a voltage is applied across the electrodes, the inert gas inside the tube ionizes and current starts flowing through it. It creates a pinkish red glow. Because of the flow of current the temperature increases and this caused the sodium to vaporise. The sodium vapor then stabilizes the electric arc and sodium vapor creates a monochromatic yellow light. Advantages & Use Human eyes can detect light from wavelength 390 - 700 nm , and sodium vapor generates light of around 600nm wavelength which is quite useful zone of visibility. That means most of the energy coming out this lamps is in the form of visible light...