Er. Nirdesh Singh Karki 
Introduction TO Bipolar Junction Transistor The transistor is a solid- state device whose operation depends upon the flow of electric charge carries within the solid. A transistor consists of two P-N junctions formed by sandwiching either P-type or N-type semiconductor between a pair of opposite types. Accordingly, there are two types of transistors, namely: 1. … Read more
Introduction to pipe flow: A pipe is a closed conduit (channel) which is used for carrying fluids under pressure. Pipes are commonly circular in section. The fluid in the pipes are subjected to frictional resistance due to shear stress. Reynolds experiment and flow based on Reynolds number. Reynolds experiment is used to display laminar, transion … Read more
Intrinsic and Extrinsic Semiconductor Intrinsic conductor An intrinsic semiconductor is one which is made of the semiconductor material in its extremely pure form. A semiconductor is not truly intrinsic unless its impurity content is less than one part in 100 million parts of semiconductor. In an intrinsic semiconductor, even at room temperature, hole electron pairs … Read more
Formation of Himalaya Shifting of Indian plate Block Diagram of The Himalaya The Nepal Himalaya • The longest division of the Himalaya• Extended about 800 Km• Starts from west at the Mahakali River• Ends at the east by the Tista River Longitudinal Division of Himalayan Range Terai Zone (Gangetic Plain) • Northern Terai(Bhabhar Zone)• Middle … Read more
Bisection Method: This method is based on the repeated application of intermediate value property. Let, F(x) be continuous between a and b. Consider, F(a) be negative and F(b) be positive. Then, the first approximation of the root is x1= (a+b)/2 , if F(x1)= 0 then x1 is root of F(x)=0. Otherwise, the root lies between … Read more
Rock Mass Classification Rock mass: The large volume of rock intersected by discontinuities is known as rockmass.The rock mass is heterogeneous in nature due to variation in rock type,discontinuities and degree of weathering.Rock mass = Intact rock + DiscontinuitiesThe discontinuities highly influence the overall strength of rock mass. Strength of rock mass < Intact rock … Read more
SITE INVESTIGATION INTRODUCTION • For all civil engineering projects like reservoirs, dams, tunnels, roads,bridges, and buildings, a detailed knowledge about the project site isvery necessary. It is essential to investigate the engineering properties ofrock or soil at the site.• Site investigation is defined as the overall evaluation of specific sitecondition which is selected for construction … Read more
Geological Work of Sea Sea ErosionA sea may be defined as the enormously large continuous body of water formed over depressed parts of the earth surface.Deep seas with average depth of more than 4 km are termed as oceans. A sea is thus part of ocean which is closer to continental land Terminology Sea wavesSea … Read more
Various landform on the surface of the earth Mountain Plateaus Shield Mountain• Mountain may be defined as any raised or elevated portion of thelandmass that is higher than the surrounding area.• A long and narrow part of mountain is called Ridge.• Mountains have complex internal structure due to folding, faulting,volcanic activity and igneous intrusion. Mountain … Read more
Hydrogeology The term Hydrogeology (popularly known as Groundwater Hydrology) is branch of geology that deals with comprehensive study the occurrence, distribution, movement, and geological interaction of water in the earth’s crust, especially groundwater. River channel Morphology River channel morphology refers to the channel pattern and channel geometry at several points along a river channel. It … Read more