Most Important Points | DC Circuits

1. An independent source which can deliver or absorb energy continuously is called an Active Element.
2. The resistivity of Annealed Copper at 20 degree centigrade is 1.725 x 10^-8 ohm-m.
3. Of all Pure Metals, the Resistance increase with an increase in temperature.
4. Resistance of Carbon, Electrolyte and Insulating Materials decrease with an increase in temperature.
5. Of Alloys, the resistance increase very slightly with increase in temperature. Alloy used in electrical work, such as manganin shows no change of resistance for considerable variation of temperature. An alloy is a metal that is made by mixing two or more type of metals together.
1. Bronze = Copper + Tin
6. Ohm's Law - The current flowing through a conductor is directly proportional to the potential difference existing between the two ends of the conductor. (Temperature Constant)
7. Maximum Power Transfer Theorem - Power transfer to the load is maximum when load resistance R is equal to the Thevenin's resistance Rth of the network.

Author and Reference:

Author: Mr. Paramjeet Singh Jamwal, Former Lecturer, Guru Nanak Education Trust Group of Institutions (GNET), Roorkee.

Reference: V N Mittle and Arvind Mittal, "Basic Electrical Engineering".