# Best Topics for Electrical Engineer

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
• 1stband = 1st number
• 2ndband = 2nd number
• 3rdband = # of zeros/multiplier
• 4thband = 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(XL2 + XC2)
• XL=Inductive Reactance = 2IIFL in Ohms
• XC= 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 = V2/ 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.