50 Basic Electrical Engineering -Important MCQs For All Exams. -

Basic electrical engineering serves as the foundational cornerstone of modern technology, powering the devices and systems that have become integral to our daily lives. It is the study of the fundamental principles and components that make electricity accessible and manageable. Whether you’re fascinated by the inner workings of electronic gadgets, aspire to design cutting-edge circuits, or simply seek to enhance your understanding of the electrical world around you, this article delves into the essential concepts, terms, and key principles of basic electrical engineering. From voltage and current to resistors and circuits, join us on a journey through the fundamental knowledge that empowers our interconnected world.

Here’s a basic data table for electrical engineering with key electrical quantities and units:

Quantity	Symbol	Unit	Description
Voltage	V	Volt (V)	Electric potential difference
Current	I	Ampere (A)	Flow of electric charge
Resistance	R	Ohm (Ω)	Opposition to current flow
Power	P	Watt (W)	Rate of energy transfer
Capaciyance	C	Farad (F)	Ability to store electric charge
Inductance	L	Henry (H)	Ability to induce electromotive force
Electric Charge	q	Coulomb (C)	Measure of electric charge
Frequency	F	Hertz (Hz)	Cycles per second
Electric Field Strength	E	Volt per meter (V/m)	Force experienced by a charge
Magnetic Field Strength	H	Ampere per meter (A/m)	Magnetic field intensity
Electrical Conductivity	σ(sigma)	Siemens per meter (S/m)	Material’s ability to conduct current
Magnetic Permeability	μ (mu)	Henry per meter (H/m)	Material’s ability to support a field
Power Factor	PF	Unitless	Efficiency of AC power transfer

Basic electrical engineering

Important Terms

Voltage (V):
- Definition: Voltage, often referred to as electric potential, is the electric force or potential difference that drives the flow of electric current in a circuit.
- Question: What unit is used to measure voltage?
- Ans-Volt.
Current (I):
- Definition: Current is the flow of electric charge (usually electrons) through a conductor over time.
- Question: What unit is used to measure electric current?
- Ans-Ampere
Resistance (R):
- Definition: Resistance is the opposition to the flow of electric current in a circuit. It is measured in ohms (Ω).
- Question: What is Ohm’s Law, and how is it represented mathematically?
Circuit:
- Definition: A circuit is a closed loop or path through which electric current can flow. It typically consists of components like resistors, capacitors, and conductors.
- Question: What are the two main types of electrical circuits?
Conductor:
- Definition: A conductor is a material that allows electric current to flow easily through it due to its low resistance.
- Question: Give an example of a good electrical conductor.
Insulator:
- Definition: An insulator is a material that does not allow electric current to flow easily through it due to its high resistance.
- Question: Name a common insulating material.
Circuit Diagram:
- Definition: A circuit diagram is a graphical representation of an electrical circuit, using symbols to represent components and their connections.
- Question: What is the symbol used to represent a resistor in a circuit diagram?
Series Circuit:
- Definition: A series circuit is a circuit configuration where components are connected in a single path so that the same current flows through each component.
- Question: In a series circuit, how does adding more resistors affect the total resistance?
Parallel Circuit:
- Definition: A parallel circuit is a circuit configuration where components are connected in multiple paths, and the voltage across each component is the same.
- Question: In a parallel circuit, how does adding more resistors affect the total resistance?
Power (P):
- Definition: Power is the rate at which electrical energy is transferred or consumed in a circuit. It is measured in watts (W).
- Question: How is power related to voltage and current according to the power formula?
Ohm’s Law:
- Definition: Ohm’s Law states that the current (I) flowing through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R) between them.
- Question: Write down Ohm’s Law equation.
Capacitor:
- Definition: A capacitor is an electrical component that stores and releases electrical energy in the form of an electric field.
- Question: What is the unit of capacitance, and how is it symbolized?
- Ans-Farad, C

Basic electrical engineering

Inductor:
- Definition: An inductor is a passive electrical component that stores energy in the form of a magnetic field when current flows through it.
Transformers:
- Definition: Transformers are devices that transfer electrical energy between two or more circuits through electromagnetic induction, often used to change voltage levels.
Frequency (f):
- Definition: Frequency is the number of complete cycles of alternating current (AC) in one second and is measured in hertz (Hz).
Impedance (Z):
- Definition: Impedance is the total opposition to the flow of alternating current in a circuit, including both resistance and reactance (inductive or capacitive).
Rectifier:
- Definition: A rectifier is an electrical device that converts alternating current (AC) into direct current (DC).
Diode:
- Definition: A diode is a semiconductor device that allows current to flow in one direction only, often used in rectification and signal demodulation.
Transistor:
- Definition: A transistor is a semiconductor device that amplifies or switches electronic signals, and it is a fundamental component in modern electronics.
Integrated Circuit (IC):
- Definition: An integrated circuit is a compact arrangement of transistors, diodes, and other components on a single chip, serving various electronic functions.
Ground (Earth):
- Definition: Ground, also known as Earth, is a reference point in electrical circuits that serves as a common return path for electrical currents and a safety measure.
Short Circuit:
- Definition: A short circuit occurs when an unintended low-resistance path is created in a circuit, allowing current to flow in an unintended way, often causing overheating or damage.
Ohmmeter:
- Definition: An ohmmeter is a measuring instrument used to measure the electrical resistance of a component or circuit.
Voltage Regulator:
- Definition: A voltage regulator is a device or circuit that maintains a constant output voltage despite variations in input voltage or load conditions.
Ampere (A):
- Definition: The ampere is the SI unit of electric current, representing one coulomb of charge passing through a conductor per second.
Kirchhoff’s Laws:
- Definition: Kirchhoff’s Laws are a set of fundamental principles in electrical circuit theory, including Kirchhoff’s Current Law (KCL) and Kirchhoff’s Voltage Law (KVL).
Semiconductor:
- Definition: A semiconductor is a material with electrical conductivity between that of a conductor and an insulator. It is the basis of modern electronic devices.
Power Factor:
- Definition: Power factor is a measure of how effectively electrical power is converted into useful work output in an AC circuit.
Electromotive Force (EMF):
- Definition: Electromotive force is a term used to describe the electrical potential difference or voltage generated by a source, such as a battery or generator.
Digital Signal Processing (DSP):
- Definition: Digital Signal Processing is the use of digital techniques to manipulate and process analog or digital signals, often used in telecommunications and audio processing.

Capacitor and its Unit & Uses

A capacitor is an electrical component used in electronic circuits to store and release electrical energy. It consists of two conductive plates separated by an insulating material called a dielectric. When a voltage is applied across the plates, it causes electrons to accumulate on one plate and an equal number of electrons to be removed from the other plate, creating an electric field between them. This electric field stores energy in the form of an electric charge.

Here’s a basic numerical problem involving capacitors:

Problem: You have a capacitor with a capacitance of 10 microfarads (µF) and a voltage of 12 volts (V applied across its plates. Calculate the charge stored in the capacitor.

Solution: The formula to calculate the charge (Q) stored in a capacitor is:

Q=C⋅V

Where:

Q is the charge stored in the capacitor (in coulombs, C).
C is the capacitance of the capacitor (in farads, F).
V is the voltage applied across the capacitor (in volts, V).

In this problem, we are given:

Capacitance (C) = 10 µF (microfarads)
Voltage (V) = 12 V

Now, plug these values into the formula: Q=(10×10−6F)⋅(12V)=0.00012C

So, the charge stored in the capacitor is 0.00012 coulombs or 120 microcoulombs (µC).

That’s the solution to the numerical problem involving a capacitor. If you have any more questions or need further clarification, feel free to ask!

Here are some basic electronics terminology tables. These tables provide a basic overview of common terminology in the field of Basic Electrical Engineering & electronics. Understanding these terms is essential for anyone starting to learn about electronics and circuit design.

1. Components- Basic Electrical Engineering

Components- Basic Electrical Engineering

Term	Definition
Resistor	A passive two-terminal component that resists the flow of electric current.
Capacitor	A passive component that stores and releases electrical energy.
Inductor	A passive component that stores energy in a magnetic field.
Diode	A semiconductor device that allows current to flow in one direction only.
Transistor	A semiconductor device used for amplification and switching of electronic signals.
Integrated Circuit (IC)	A compact arrangement of transistors and other components on a single chip.
LED (Light Emitting Diode)	A diode that emits light when current flows through it.
Resistor Network	A collection of resistors in a single package.
Potentiometer	A variable resistor used for adjusting voltage or current in a circuit.
Crystal Oscillator	A device that generates precise and stable electrical frequencies.

2. Circuits- Basic Electrical Engineering

Term	Definition
Circuit	A closed loop or path through which electric current flows.
Series Circuit	Components are connected in a single path. The same current flows through each component.
Parallel Circuit	Components are connected in multiple paths. Voltage is the same across each component.
Ground	A reference point in a circuit, often considered 0 volts.
Voltage	Electrical potential difference measured in volts (V).
Current	The flow of electric charge, measured in amperes (A).
Resistance	Opposition to the flow of current, measured in ohms (Ω).
Ohm’s Law	A fundamental relationship: V = I * R, where V is voltage, I is current, and R is resistance.
Power	The rate at which work is done or energy is transferred, measured in watts (W).
Short Circuit	A low-resistance path that allows excessive current flow, often causing damage.

3. Electrical Measurements:

Term	Definitions
Voltmeter	A device used to measure voltage in a circuit.
Ammeter	A device used to measure current in a circuit.
Ohmmeter	A device used to measure resistance in a component or circuit.
Multimeter	A versatile instrument that combines the functions of a voltmeter, ammeter, and ohmmeter.
AC (Alternating Current)	Current that periodically changes direction.
DC (Direct Current)	Current that flows in one direction only.
Frequency	The number of cycles per second in an AC waveform, measured in hertz (Hz).

4. Semiconductors:

Term	Definition
Semiconductor	A material with electrical properties between those of a conductor and an insulator.
Silicon	The most common semiconductor material used in electronics.
PN Junction	The interface between a P-type and N-type semiconductor material.
Semiconductor Diode	A diode made from semiconductor materials.
Doping	The process of intentionally adding impurities to a semiconductor to alter its properties.
Silicon Wafer	A thin, circular slice of crystalline silicon used as a substrate for manufacturing ICs.
MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor)	A type of transistor widely used in digital circuits.