Electrical: Part - 1

 

 ELECTRICAL ENGINEERING
Part- 1

1. Voltage (V)

• Unit: Volt (V)
• Description: Voltage is the electrical potential difference between two points in a circuit. It is what pushes electric current through a conductor.
• Symbol: $V$ or $E$

2. Current (I)

• Unit: Ampere (A)
• Description: Electric current is the flow of electric charge through a conductor. One ampere represents the flow of one coulomb of charge per second.
• Symbol: $I$
• Sub-units:
  • Milliampere (mA): 1 mA = $10^{-3}$ A
  • Microampere (µA): 1 µA = $10^{-6}$ A

3. Power (P)

• Unit: Watt (W)
• Description: Power is the rate at which electrical energy is consumed or produced. It is the product of voltage and current.
• Formula: $P = VI$
• Symbol: $P$
• Sub-units:
  • Kilowatt (kW): 1 kW = 1,000 W
  • Megawatt (MW): 1 MW = 1,000,000 W

4. Energy (E)

• Unit: Watt-hour (Wh) or Kilowatt-hour (kWh)
• Description: Electrical energy is the total amount of work done by the electrical system. It is power multiplied by time.
• Symbol: $E$
• Sub-units:
  • Kilowatt-hour (kWh): 1 kWh = 1,000 Wh

5. Resistance (R)

• Unit: Ohm (Ω)
• Description: Resistance is the opposition that a material offers to the flow of electric current.
• Symbol: $R$
• Formula: $R = V/I$

6. Conductance (G)

• Unit: Siemens (S)
• Description: Conductance is the reciprocal of resistance and measures how easily electricity flows through a material.
• Symbol: $G$
• Formula: $G = 1/R$

7. Capacitance (C)

• Unit: Farad (F)
• Description: Capacitance is the ability of a system to store an electric charge.
• Symbol: $C$
• Sub-units:
  • Microfarad (µF): 1 µF = $10^{-6}$ F
  • Nanofarad (nF): 1 nF = $10^{-9}$ F
  • Picofarad (pF): 1 pF = $10^{-12}$ F

8. Inductance (L)

• Unit: Henry (H)
• Description: Inductance is the property of an electrical conductor by which a change in current induces an electromotive force.
• Symbol: $L$

9. Frequency (f)

• Unit: Hertz (Hz)
• Description: Frequency refers to the number of cycles per second in an alternating current (AC).
• Symbol: $f$

10. Impedance (Z)

• Unit: Ohm (Ω)
• Description: Impedance is the combination of resistance, inductive reactance, and capacitive reactance in an AC circuit.
• Symbol: $Z$
• Formula: $Z = \sqrt{R^2 + X^2}$, where $X$ is the reactance.

11. Reactance (X)

• Unit: Ohm (Ω)
• Description: Reactance is the opposition to the change of current in a circuit due to inductance or capacitance.
• Symbol: $X$
• Types:
  • Inductive Reactance: $X_L = 2\pi fL$
  • Capacitive Reactance: $X_C = 1 / (2\pi fC)$

12. Charge (Q)

• Unit: Coulomb (C)
• Description: Electric charge is the quantity of electricity transported by one ampere in one second.
• Symbol: $Q$
• Formula: $Q = It$

13. Electric Field (E)

• Unit: Volt per meter (V/m)
• Description: The electric field is the force per unit charge exerted on a positive test charge placed in a field.

14. Magnetic Field Strength (H)

• Unit: Ampere per meter (A/m)
• Description: Magnetic field strength refers to the magnetic force in a particular region of space.

15. Magnetic Flux (Φ)

• Unit: Weber (Wb)
• Description: Magnetic flux is the amount of magnetic field passing through a surface.
• Symbol: $\mathrm{\Phi }$

16. Magnetic Flux Density (B)

• Unit: Tesla (T)
• Description: Magnetic flux density is the strength of the magnetic field per unit area.

17. Apparent Power (S)

• Unit: Volt-ampere (VA)
• Description: Apparent power is the product of the current and voltage in an AC circuit, regardless of the phase angle between them.
• Formula: $S = V \times I$
• Sub-units:
  • Kilovolt-ampere (kVA): 1 kVA = 1,000 VA
  • Megavolt-ampere (MVA): 1 MVA = 1,000,000 VA

18. Reactive Power (Q)

• Unit: Volt-ampere reactive (VAR)
• Description: Reactive power is the portion of electricity that oscillates between the source and the load in an AC circuit due to the presence of inductance and capacitance.
• Formula: $Q = V \times I \times \sin(\theta)$, where $\theta$ is the phase angle between voltage and current.
• Sub-units:
  • Kilovolt-ampere reactive (kVAR): 1 kVAR = 1,000 VAR
  • Megavolt-ampere reactive (MVAR): 1 MVAR = 1,000,000 VAR

19. Power Factor (PF)

• Unit: Dimensionless (No unit)
• Description: Power factor is the ratio of real power (P) to apparent power (S). It represents the efficiency with which electrical power is converted into useful work.
• Formula: $PF = P/S = \cos(\theta)$, where $\theta$ is the phase angle.

20. Electric Potential Energy

• Unit: Joule (J)
• Description: The potential energy stored in a system due to its electric charge and position in an electric field.
• Symbol: $U$ or $W$
• Formula: $U = QV$, where $Q$ is charge and $V$ is voltage.

21. Electric Conductivity (σ)

• Unit: Siemens per meter (S/m)
• Description: Conductivity measures a material's ability to conduct electric current.
• Symbol: $\sigma$

22. Electric Resistivity (ρ)

• Unit: Ohm meter (Ω·m)
• Description: Resistivity is a material property that quantifies how strongly a material opposes the flow of electric current.
• Symbol: $\rho$
• Formula: $\rho = R \times A / L$, where $R$ is resistance, $A$ is cross-sectional area, and $L$ is the length of the material.

23. Permittivity (ε)

• Unit: Farad per meter (F/m)
• Description: Permittivity is a measure of how easily a material allows electric fields to pass through it.
• Symbol: $\varepsilon$

24. Permeability (μ)

• Unit: Henry per meter (H/m)
• Description: Permeability is the ability of a material to support the formation of a magnetic field within itself.
• Symbol: $\mu$

25. Electric Displacement (D)

• Unit: Coulomb per square meter (C/m²)
• Description: Electric displacement is the amount of electric charge per unit area in a dielectric material.
• Symbol: $D$

26. Electric Flux (ΦE)

• Unit: Volt meter (V·m) or Coulomb (C)
• Description: Electric flux is the amount of electric field passing through a given area.
• Symbol: $\Phi_E$

27. Magnetic Field Strength (H)

• Unit: Ampere per meter (A/m)
• Description: The intensity of the magnetic field in a specific direction.
• Symbol: $H$

28. Electromotive Force (EMF)

• Unit: Volt (V)
• Description: Electromotive force is the voltage generated by a source like a battery or a generator, often driving current around a circuit.
• Symbol: $\mathcal{E}$

32. Complex Power (S)

• Unit: Volt-ampere (VA)
• Description: Complex power is used in AC circuits to represent both real and reactive power. It is represented as a complex number, where the real part is the real power and the imaginary part is the reactive power.
• Formula: $S = P + jQ$

33. Power Density

• Unit: Watt per square meter (W/m²)
• Description: Power density is the amount of power per unit area, often used in the context of electromagnetic radiation and electrical heating.