01․ Which of the following power planets is the least reliable
Wind energy is least reliable energy source by providing signification amounts of electricity. Wind power, as an alternative to fossil fuels is plentiful, renewable, widely distributed, clean, produces no green house gas during operation and use little land.
02․ A hydroelectric power station is commonly found in
Hydroelectric power station are usually located in high hilly areas, where the dam can be easily built and large reservation can be obtained.
03․ The power output from an hydroelectric plants depend on
The power developed by a hydro power plant depends upon the discharge and head and is directly proportional to their product and also proportional the system efficiency. The electrical power P is given as
P = WQHð × 9.81 × 10-3 KW.
Where W is specific weight of water in Kg/m3, Q is rate of flow of water in m3 / S, H is height of fall or head in meters and η is overall efficiency of operation.
04․ In hydroelectric power plants
As the large area required and construction cost is enormously high and takes a long time for erection, so initial cost is high for above reason. The operating cost is low because of fuel cost. The fuel of hydroelectric plant is water which is available of free of cost.
05․ Water hammer is developed in a
A reduction in load on the generator causes the governor to close the turbine gates and thus create an increased pressure in the penstock. This may result in water hammer phenomenon and may need pipe of extraordinary strength to withstand it otherwise the penstock may brust. So water hammer is developed in penstock.
06․ With reference to hydrometer station, the graphical representation of the discharge as function of time is known as
A hydro-graph is a graphical representation between discharge or flow with time in a hydro power plant.
07․ An hydro-graph indicates
An hydro-graph provides the following information 1. The discharge at any time during the period under consideration. 2. The average run off during of period. 3. The maximum and minimum run off during the period. 4. Total volume of discharge up to any time given by the area under the curve up to that time.
08․ A penstock is used as a condition between
Penstock is a closed conduit which connect the forebay or surge tank to the scroll case of turbine.
09․ In hydro power stations what is an enlarged body of water just above the intake and used as a regulating reservoir called
The forebay server as a regulating reservoir storing water temporarily during light load period and providing the same for initial increase on account of increasing lad during which water in the canal is being accelerated. A forebay may be considered as an enlarged body of water just above the intake to store water temporarily to meet the hourly load.
10․ The function of a surge tank is to
Surge tank is provided to absorb sudden changes in water requirements and reduce water hammer and negative pressure in penstock.