The average value of the sine wave over one complete cycle is actually zero. Hence, for a sine wave, the average value is defined over half the period. The average value expressed in terms of peak value is given by Average value = 0.637 × peak value
When two solid surfaces are brought into contact, a finite normal force is needed to pull the two solids apart. This force is known as the force of adhesion or simply adhesion. The coefficient of adhesion () defined as the ratio of tractive effort required to propel the wheel of a locomotive to its adhesive weight. Adhesion traction is the friction between the drive wheels and the steel rail. µ = Ft/W Where Ft = Tractive effort W = Adhesive Weight
In the above option, the wood has the lowest calorific value. Its value is around 17000 – 20000 kilojoule/kg. The calorific value of LPG is 55000 kilojoule/kg. The calorific value of Kerosene oil is 45000 kilojoule/kg. The calorific value of hydrogen oil is 150000 kilojoule/kg.
Penstock Penstock pipe is used to bring water from the dam to the hydraulic turbine. Penstock pipes are made up of steel or reinforced concrete. The turbine is installed at a lower level from the dam. The penstock is provided with a gate valve at the inlet to completely close the water supply. It has a control valve to control the water flow rate into the turbine.