Basics of Electrical Engineering

Atom
            It has a central core known as nucleus. It contains two types of particles one is known as proton and carries positive charge. The other is neutron, which is electrically neutral, that is it does not carries any charge and around the nucleus the electron which carry negative charge revolves in an elliptical path. The atoms are electrically neutral. The total number of neutron and proton are known as atomic weight.
Current
Current is a flow of electrons. The standard unit of current is ampere (A). One ampere of current represents one coulomb of electrical charge (6.24 x 10^18 charge carriers) moving past a specific point in one second
Potential Difference
Potential difference is work done to move a unit positive charge. The basic unit of measure for potential difference is voltage (V).
Resistance
Resistance is the opposition that a substance offers to the flow of electric current. The standard unit of resistance is ohm
Effect of temperature on the resistance of conductors
In the case of conductor, the resistance increases in increase in temperature.
In case of conductor, the valance band and conduction band overlap with each other. So, there are excess electrons in the conduction band of the conductor. When temperature increases, more electrons will go to the conduction band by absorbing the energy so, the conduction band become crowded and there will be more more collision between the electrons which increases the resistance
Ohm’s law
Ohm’s law is the mathematical relationship among voltage, current and resistance.  The Ohm’s law states that current through a conductor between two points is directly proportional to the voltage across the two points
V = I x R
Kirchhoff”s Law
1)      The law that the algebraic sum of the current flowing towards any point in an electric network is zero
2)      The law that the algebraic sum of the product of the current and resistance in the conductors forming a closed loop in a network is equal to the algebraic sum of the electromotive forces in the loop
Electrical work
Electrical work is the work done on a charged particle by an electric field.
Electrical Energy
Electrical energy is the energy newly derived from electric potential energy or Kinetic energy

Calculation


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