Electrical Quantities

This PPT is useful to all the students who study in electrical engineering and also for those students whose know about basic information of electrical quantities like charge, voltage, current, electrical power and energy.

1. Name : Panchal Dhrumil Indravadan Activity : Basic Electronics(Seminar) Branch : Computer Engineering(B.E.) Semester : Second Sem Year : 2017-18 WELCOME

2. Topic Electrical Quantities

3. Contain Electrical Quantities Electrical Charge Electrical Current Electrical Voltage Electrical Energy Electrical Power

4. Electrical Quantities To understand the operation of electric circuits we must familiar with electrical quantities such as charge, current and voltage.

5. Electrical Charge There are two types of charges: Positive charge (+) Negative charge (-) Conservation law of charges: Charge can be neither created nor destroyed. It can be only transferred. The unit of charge is Coulomb. It is denoted by C.

6. Structure of Atom

7. Three types of particles Protons Protons are positive charge (+) and it has charge of + 1.6 X 10 -19 coulombs (C).   Electrons Electrons are negative charge (-) and it has charge of – 1.6 X 10 -19 coulombs (C).   Neutron The neutron has zero charge.

8. Electrical Current Rate of flow of electrons is known as current. I = Q / t Where, I = Current, Q = Charge, t = Time If charge varies with time, so i = dq / dt Where, dq = change in charge dt = change in time

9. Electrical Current Unit of current is Ampere. It is denoted as A. 1 A = 1 C/sec 1 Coulomb of charge is the charge carried by 6.25 X 10 18 electrons. 1 mA = 10 -3 A and 1 μA = 10 -6 A

10. Electrical Voltage One Volt: A body is said to have a potential of 1 volt, if 1 joule of work is done to give it a charge of 1 coulomb. Voltage or Potential difference (P.D.): Voltage is the difference in electric potential between two points. It is expressed in volts (V) or joules per coulomb (J/C). Consider two bodies A and B having potential 5 V and 1 V.

11. Electrical Voltage So body A is at higher potential then B and the potential difference between A and B is given by VAB. v AB = v A – v B = 5 – 1 = 4 V. Voltages can be either positive or negative numbers, and it follows that v BA = − v AB . If v A > v B = Positive potential difference. If v A < v B = Negative potential difference.

12. EMF Electromotive Force ( emf ): The force which causes current to flow in the circuit is called emf . It defined as E. Its unit is volt (V).

13. Electrical Energy Total work done in an electric circuit is called electric energy. The energy over a time interval is found by integrating power, 𝑤 = ∫ 𝑝 𝑑𝑡 E = P x t Energy is expressed in watt-seconds or joules (J). It is expressed in electric utility bills in kilo watt hours (kWh). 1 kWh = 3.6 × 10 6 J.

14. Electrical Power Power is defined as the rate of doing work or the rate of change of energy dw / dt . Power = Work done / Time. P = I 2 R = V 2 /R Unit of power is Watt. or J/Sec or Volt Ampere. 1 kWh = 1 kW x 1 hr = 10 3 x 60 x 60 sec = 36 X 10 5 Watt Sec = 3.6 X 10 6 J. 

15. References Inspiration from Asst. Prof. Rajkumar Joshi and Asst. Prof. Kyati Singh Notes of Basic Electronics Text book of Basic Electronics Image from Google images Some my own knowledge

16. Thank You