Theory for Basics of Electrical Engineering

This section presents basic topics of Electrical Engineering. Various examples are added for the reference.

1. Basic properties of electrical engineering
2. SI units and derived units for electrical engineers
3. Electrical symbols
4. Ohm's law
5. Resistors in series
6. Resistors in parallel
7. Polarity of voltage and direction of current
8. Voltage sources in series
9. Point source
10. Series-Parallel Circuits
11. Kirchhoff's current law
12. Kirchhoff's voltage law
13. Voltage divider
14. Current divider
15. Branch current analysis
16. Superposition principle
17. Thevenin theorem
18. Norton theorem
19. Delta to Wye conversion with examples
20. Wye to Delta conversion with examples
21. Resistive bridge

Examples

1. What is the maximum voltage you can apply to 1/4 watt resistor
2. Equivalent resistance of 1,2,3 or 4 same resistors
3. What current will flow through a 1 kW heater having 5 ohms resistance
4. An electrical circuit has three resistors which three resistors with two having dropped 5 V and 12 V. A current of 50 mA is flowing through the circuit. Find the value of input source

Power/Energy Examples

1. A 3 kW boiler runs for 10 minutes How much it cost you if rate is $0.15/kWh

Resistors in parallel

1. Four parallel resistors of each 10 ohm

Series-Parallel network examples

1. Series-Parallel network Example # 1: 4k, 8k and 12k resistors

Kirchhoff's Current Law Example

1. H shaped bridge with 5 resistors [Easy]
2. Kirchhoff's Current Law Example 2: 9 Resistors and 5 Unknown branches

Current Divider Examples

1. Current divider example # 1: Two resistors with 500 ohm and 800 ohm
2. Current divider example # 2:  Two equal resistors having values 200 ohm
3. Current divider example # 3: Finding value of unknown resistor
4. Current divider example # 4: Designing a current divider for 20 mA current
5. Current divider example # 5: Impact of adding another resistor
6. Current divider example # 6: How to apply current divider for three resistors

Norton theorem Examples

1. Norton theorem example # 1: Norton theorem for input with two voltage sources