In this tutorial, we are going to learn about Best Topics for Electrical Engineer.

**What is Current?**

- Movement of called Electricity, Simply it is electronics called current.
- If a charge is forced to move because of a potential difference (voltage) current is produced.
- In conductors-free electrons can be forced to move, while they require little work to be moved.
- So current is charge in motion.

**What is Amperes?**

- Current indicates the intensity of the electricity in motion. The symbol for current is (for intensity) and is measured in
**amperes.** - Current is invented by
**Amperes**so unit of current is ampere. - The definition of current is equal to I =Q/T.
- Where I is current in amperes, Q is charge in coulombs, and T is charge in coulombs, and T is time in seconds

**What is Voltage?**

- Movement of electron is called Electricity. We need some force move Electron from one place to place that force in Electrical term is called
**“VOLTAGE”**or**“ELECTRO MOTVIE FORCE”** - For voltage, Potential refers to the possibility of doing work.
- The symbol for potential difference is E (for electromotive force).
- It is also called unit of potential difference is the volt (V)
- I volt is a measure of the amount of work required to move IC of charge.

**What is Closed Circuit?**

- In applications requiring the use of current, electrical component are arranged in the form of a circuit.
- A circuit is defined as a path for current flow.
- If one circuit forms the closed path only that circuit will work.

**What is Open Circuit?**

- Current can only exist when there is conductive path. In the circuit =0, since there is no conductor between points a and b. we reoffered to this is as an open circuit.

**What is Direct Current?**

- Current that is powered by battery sources are termed direct current circuits.
- It is the flow of charge in just one direction so no frequency.
- Example: – Battery and Solar cell output and DC generator.

**What is Alternating Current?**

- An alternating voltage source periodically alternate or reverses in polarity.
- Frequency (Eg:-50Hz or 60Hz) it’s decided by power generation Station.
- In our how house maximum all appliances working in AC supply.

**What is Resistance?**

- It is use to opposition to the flow of current is termed resistance and it is Bidirectional component.
- When a wire can become hot from the flow of current is evidence of resistance.
- Conductors have very little resistance.
- Insulators have large amounts of resistance.
- Unit of Resistance is Ohms.
- Voltage, current and resistance are related through Ohm’s law, resistors are a good way to control voltage and current in your circuit.

**Resistor Color Code Band:**

- Resistor color codes
- 1
^{st}band = 1^{st }number - 2
^{nd}band = 2^{nd}number - 3
^{rd}band = # of zeros/multiplier - 4
^{th}band = tolerance

**What is Ohm’s Law?**

- When the amount of current flow in a circuit which is dependent on its resistance and the applied voltage. Specifically I =V/R.
- If you know any two of the factors V.I, and R you can calculate the third.
- It can be applied to both AC and DC circuit. Its apply Linear circuits.
- For DC Circuits-

** V-IR in Volts**

Current I = V/R (For DC)

Voltage V = IR (For DC)

Resistance R = V/I (For DC)

- For AC Circuits:-
- V = IZ in Volts
- I=Current flow in the circuit in amps
- Z=Impedance in the circuit Ohms =
*f*(X_{L}^{2}+ X_{C}^{2}) - X
_{L}=Inductive Reactance = 2IIFL in Ohms - X
_{C}= Capacitive Reactance=1/(2IIFc in ohms.

**What is Power?**

- The unit of power is watt (W).
- It is called when any works is done over time.
- Power is divided in Real power. Reactive power and Apparent Power (Explain in another video)
- One watt of power is equal to the work done in one second by one volt moving one coulomb of charge. When one coulomb a second then it is an ampere.
- Power in watts = volts x amperes (Real Power).
- P = V x I in watts
- P = I2 x R in watts
- P = V
^{2}/ R in watts

**What is Capacitors?**

- A capacitor stores electrical energy.
- Capacitance is measured in Farads. The small capacitors usually used in electronics are often measured in microfarads and nano farads.
- Electrolyte capacitor stores energy in the electrical field between its plates.
- Some capacitors are polarized. Note the different length terminals on one the capacitors.
- The shorter terminal of capacitor goes on the negative side (cathode).

**What is Diode?**

- It is a one way valve for electricity and component with an asymmetrical transfer characteristic. A diode has low resistance (Ideally zero resistance) in one direction and high resistance (infinite resistance) in the other direction. Rectifier circuits and so many circuits diode used.
- Diodes will protect your electronics.