small gaps between rails

A small gap is provided between the rails on railway tracks to make provision for the expansion of rails during summer, otherwise, the rails may bulge due to expansion causing train accidents. If a metal wire is used in a pendulum, its length c..

Summary - Energy band of a solid is the large number of energy levels confined in a small region of energy range of a given solid, constitute what is known as energy bands. In some solids, there is an energy gap in between the energy bands. This energy gap is called fo..

The valence band is completely filled and conduction band is empty. The E g a p is also less i.e., of the order of few eV. At zero kelvin, electrons are not able to cross this forbidden gap and so behave like insulators. But as temperature is increased, electrons in valence band (VB) ..

. The major problem of corrosion occurs with iron (or steel) as it is used as a structural material in industries like construction, infrastructure, bridges, rail transport power transmission, shipbuilding, automobiles, heavy industries etc. Aluminium, another useful structural metal, als..

Sometimes at the end points of the wire, some length is found under the metallic strips and as a result, in addition of length l 1 or (100 - l 1 ), some additional length should be added for accurate measurements. The resistance due to this additional length is called end resistance. If the end r..

Oxygen is One-fifth by Volume in Air - The part of air that helps in combustion or burning is oxygen gas. You can perform the following experiment to determine the percentage of oxygen in air. You will need a trough, a bell jar, an evaporation dish and a small piece of yellow phosphorus. ..

. One of them pressed the button that closed the glass wall. The food bowl jammed it which caused a gap. Ch-tsal then escaped into the human world through this gap. Ch-tsal sensed that he could breathe in the air and the temperature was pleasant. He would have sent a message of ..

Pressure - When a force is applied on a surface in a direction perpendicular to the surface, the force is called thrust. Pressure on a solid surface is the thrust per unit area of the surface. Pressure is a scalar quantity. The SI unit of Pressure is N m - 2 or Pascal (Pa) Pressure varies according..