DC CIRCUITS AND THEOREMS & BASIC ELECTRICAL ELEMENTS.pptx

DC CIRCUITS AND THEOREMS & BASIC ELECTRICAL ELEMENTS

1. UNIT -1 DC CIRCUITS AND THEOREMS 1.1 DEFINITIONS OF VOLTAGE AND CURRENT 1.1.1 - Basic electrical elements 1.1.2 - Current definition 1.1.3 - current unit and symbol 1.1.4 - voltage definition 1.1.5 - voltage unit and symbol

2. 1.1.1 - BASIC ELECTRICAL ELEMENTS All matter consists of minute particles called molecules. Molecules are made up of more minute particles called atoms.

3. Inside the atom there is a central nucleus and a number of electrons around the nucleus. The nucleus contains protons and neutrons. Central Nucleus

4. 1.1.1 - BASIC ELECTRICAL ELEMENTS Positive charge on nucleus is exactly = total negative charge due to all the electrons surrounding the nucleus. In a normal atom, Electrons revolve around the nucleus in elliptical orbits.

5. The first orbit has a maximum of 2 electrons, second 8 electrons. Third 18 electrons and so on. Number of electrons present in the orbit is 2n 2 , where 'n' is the orbit number 1.1.1 - BASIC ELECTRICAL ELEMENTS

6. 1.1.2 – CURRENT DEFINITION Flow of electron in any conductor is called current. Current = charge / time. I=Q/t. Q is in coulomb. t is in seconds. One ampere is defined as the motion of electric charge at the rate of one coulomb per second.

7. 1.1.3 – CURRENT UNIT AND SYMBOL Represented by the letter I. Its unit is ampere.

8. 1.1.4 – VOLTAGE DEFINITION Difference of potentials between two points called potential difference (Voltage). One volt is defined as the potential difference across a resistance of one ohm carrying a current of one ampere.

9. 1.1.5 - VOLTAGE UNIT AND SYMBOL Voltage is represented by the letter V. Unit is volt