February 7, 2026

Explore Our Topics!

Check out the extensive list of topics we discuss: 

  1. Tech and AI Blogs
  2. Communication Protocols:
    USB 
    - RS232 
    Ethernet 
    AMBA Protocol: APB, AHB and ASB 
    UART, I2C AND SPI
  3. Important concepts in VLSI:
    Designing a Chip? Here Are the 12 Important Concepts You Need to Know
    Metastability 
    - Setup time and Hold time
    Signal Integrity and Crosstalk effect
    Skews and Slack 
    Antenna Effect
  4. Semiconductor Memories
  5. Analog vs Digital Electronics
  6. Most Frequently Asked Questions in VLSI
  7. VLSI and Semiconductor Nuggets: Bite-Sized knowledge for Enthusiasts
  8. Common Acronyms in VLSI and Semiconductor Industry
  9. Transistors:
    BJT
    JFET
    MOSFET
    CMOS
    Transmission Gate CMOS
    Dynamic CMOS
  10. Sequential Circuits:
    Registers
    Counters
    Latches
    Flip Flops
  11. FPGA:
    ASIC vs FPGA
    FPGA Insights: From Concept to Configuration
    Full-Custom and Semi-Custom VLSI Designs: Pros, Cons and differences
    From Theory to Practice: CMOS Logic Circuit Design Rules Made Easy with Examples
  12. CMOS Fabrication:
    CMOS Fabrication
    Twin-Tub CMOS Technology
  13. Combinational Circuits
    - Logic Gates 
    - Boolean Algebra and DeMorgan's Law 
    - Multiplexer (MUX) and Demultiplexer (DEMUX) 
    - Half Adder
    - Full Adder
    - Half Subtractor
    - Full Subtractor
    - Encoders
    - Decoder
  14. Analog Electronics
    - Atoms: the Foundation of Electronics
    - Electrons, Protons and Neutrons 
    - Electron Shells, Subshells and Energy Ordering
    - Energy Band: The Key to Conductors, Semiconductors, Insulators and Dielectrics
    - Intrinsic and Extrinsic Semiconductors
    - Electric Charge and Permittivity
    - Electric Potential and Voltage
    - Basic Structure and Working of Battery
    - Understanding Resistor
    - Understanding Resistivity
    - Understanding Capacitor and Capacitance
    - Understanding Inductors and Inductance
    - Understanding Reactance
    - Understanding Impedance
    - Understanding Resonance
    - Laws of Electronics
    - OPAMP
    - Inverting and Non-inverting Amplifiers
    - Characteristics of OPAMP
    - OPAMP Application: Adder, Subtractor, Differentiator, and More!  
    - Filters
    - Hard Disk Drives Explained
    - Passive Components: Capacitors and Resistors Explained
    - LTSpice Tutorial 1: Installation and First Circuit Simulation
  15. Verilog
    - Verilog Datatypes
    - Comments, Numeral Formats and Operators
    - Modules and Ports
    - assign, always and initial keywords
    Blocking and Non-Blocking Assignments
    - Conditional Statements
    - Looping Statements
    - break and continue Statement
    - Tasks and Functions
    - Parameter and generate
    - Verilog Codes
  16. System Verilog: 
    Disable fork and Wait fork.
    Fork and Join.
  17. Project on Intel Quartus Prime and Modelsim:
    Vending Machine Controller
  18. Xilinx Vivado Projects
    1)VHDL
    Counters using Testbench code
    Flip Flops using Testbench code
    Logic Gates using Testbench code
    Full Adder using Half Adder and Testbench code
    Half Adder using Testbench code
    2)Verilog
    Logic Gates using Testbench code
    Counters using Testbench code
    Full Adder using Half Adder and Testbench code
    Half Adder using Testbench code
  19. VLSI Design Flow:
    Design Flow in VLSI
    Y chart or Gajski Kuhn Chart
  20. Projects on esim:
    Step-by-Step guide on how to Design and Implement a Full Adder using CMOS and sky130nm PDK
    Step-by-Step guide on how to Design and Implement a Half Adder using CMOS and sky130nm PDK
    Step-by-Step guide on how to Design and Implement a 2:1 MUX using CMOS and sky130nm PDK
    Step-by-Step guide on how to Design and Implement a Mixed-Signal Circuit of 2:1 Multiplexer
  21. IoT based project:
    Arduino
    Step-by-Step guide on how to Interface Load Cell using Arduino
  22. Kmaps:
    Simplifying Boolean Equations with Karnaugh Maps - Part:2 Implicants, Prime Implicants and Essential Prime Implicants. 
    Simplifying Boolean Equations with Karnaugh Maps - Part:1 Grouping Rules.
    Simplifying Boolean Equation with Karnaugh Maps.

February 6, 2026

Fundamental Laws of Electronics — The Rules That Govern Every Circuit

šŸ”¹ Introduction

Every electronic circuit, no matter how simple or complex, follows a set of fundamental physical laws. These laws explain how current flows, how voltages behave, and how electric and magnetic fields interact with matter.

In this blog, we’ll explore the core laws of electronics that form the backbone of circuit analysis and electrical engineering — from basic DC behavior to electromagnetic principles.


1️⃣ Ohm’s Law

šŸ“Œ Statement

The current through a conductor between two points is directly proportional to the voltage across the two points, provided temperature and other physical conditions remain constant.

šŸ“ Formula

V=I×R

Where:

  • V = Voltage

  • I = Current

  • R = Resistance

Ohm’s Law is the most fundamental relationship in electronics. It tells us how voltage, current, and resistance are related and is the starting point for analyzing both DC and AC circuits.


2️⃣ Kirchhoff’s Laws

When circuits become more complex with multiple branches and loops, Ohm’s Law alone is not enough. That’s where Kirchhoff’s Laws come in.


šŸ”¹ Kirchhoff’s Current Law (KCL)

šŸ“Œ Statement

The total current entering a junction equals the total current leaving the junction. This law is based on the conservation of charge — charge cannot accumulate at a node.


šŸ”¹ Kirchhoff’s Voltage Law (KVL)

šŸ“Œ Statement

The algebraic sum of all voltages around any closed loop in a circuit is zero. KVL is based on the conservation of energy and applies to both DC and AC circuits.


3️⃣ Faraday’s Law of Electromagnetic Induction

šŸ“Œ Statement

A changing magnetic flux through a circuit induces an electromotive force (EMF) in that circuit.

šŸ“ Formula

EMF=dΦdt​

Where:

  • EMF = induced voltage (volts)

  • Φ (Phi) = magnetic flux (Webers, Wb)

  • dΦ/dt = rate of change of magnetic flux with time


🧲 What Is Magnetic Flux?

Magnetic flux represents the total magnetic field (B) passing through a given surface area (A).
It indicates how many magnetic field lines pass through a surface.

  • More field lines → higher magnetic flux

  • Fewer field lines → lower magnetic flux


šŸ”„ Lenz’s Law — Direction of Induced EMF

šŸ“Œ Statement

The direction of the induced EMF (and the resulting current) is always such that it opposes the change in magnetic flux that produced it.

In simple terms:

  • Faraday’s Law tells you how much EMF is induced

  • Lenz’s Law tells you which direction it acts


šŸ“ Mathematical Meaning of the Negative Sign

Faraday’s Law is written as:

E=dΦdtE = -\frac{d\Phi}{dt}

So, Lenz’s Law is embedded in the negative sign, ensuring energy conservation.


5️⃣ Ampere’s Law

šŸ“Œ Statement

The magnetic field around a current-carrying conductor is directly proportional to the current flowing through it.

šŸ“ Integral Form (Ampere’s Circuital Law)

Bdl=μ0Ienc​

Where:


Ampere’s Law links electric current to magnetic fields, forming the basis of inductors, electromagnets, and motors.


6️⃣ Coulomb’s Law

šŸ“Œ Statement

The force between two electric charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.

šŸ“ Formula

F=kq1q2r2F = k \frac{q_1 q_2}{r^2}

This law explains:

  • Attraction between opposite charges

  • Repulsion between like charges

It is the foundation of electrostatics and electric field theory.


šŸ”š Conclusion

The laws of electronics are not just formulas — they are fundamental rules of nature that govern how electric and magnetic phenomena behave. From Ohm’s Law and Kirchhoff’s Laws for circuit analysis to Faraday’s, Lenz’s, Ampere’s, and Coulomb’s Laws for field interactions, these principles form the backbone of electronics and electrical engineering.

A strong understanding of these laws makes it easier to analyze circuits, design systems, and move confidently into advanced topics like AC analysis, electromagnetics, power electronics, and semiconductor devices.

Master these laws, and the behavior of circuits starts to feel logical rather than mysterious.

February 3, 2026

Understanding Resonance in AC Circuits — When Reactances Cancel Out

In AC circuits, frequency plays a crucial role in deciding how current flows. At one special frequency, the effects of inductors and capacitors perfectly balance each other, leading to a powerful phenomenon called resonance.

In this blog, we’ll understand what resonance is, why it happens, and how it can be visualized using a practical RLC circuit simulation.



⚡ Resonance

Resonance in an AC circuit is the condition at which the inductive reactance (Xā‚—) becomes equal to the capacitive reactance (X꜀), causing them to cancel each other out. At resonance, the circuit behaves purely resistive, and the current becomes maximum.

To understand resonance, you must understand impedance and reactance.


šŸ”Œ What Is Impedance?

In AC circuits, current and voltage change direction continuously.

So, opposition to current is not just resistance (R). There are two more components:

  • Inductive reactance (Xā‚—) — comes from inductors

  • Capacitive reactance (X꜀) — comes from capacitors

The total opposition in an AC circuit is called Impedance (Z):

Z=R2+(XLXC)2

Where:

  • XL=2Ļ€fLX_L = 2\pi f L

  • XC=12Ļ€fCX_C = \frac{1}{2\pi f C}

Notice something important:

  • Xā‚— increases with frequency

  • X꜀ decreases with frequency

But there is one special frequency where their effects cancel each other.


šŸŽÆ Resonance Condition

Resonance occurs where capacitive reactance equals inductive reactance:

XL=XC

Substitute the formulas:

2Ļ€f0L=12Ļ€f0C

Solving for frequency:

f0=12Ļ€LCf_0 = \frac{1}{2\pi\sqrt{LC}}

This frequency is called the resonant frequency.


šŸ” What Happens at Resonance?

At the resonant frequency f0:

Inductive reactance equals capacitive reactance

XLXC=0

Impedance becomes minimum

Z=R

The circuit behaves as if it has only resistance.

Current becomes maximum

I=VR

Voltage magnification occurs in L and C

Even though the net reactive effect is zero, energy continuously transfers between the inductor and capacitor:

  • Inductor stores magnetic energy

  • Capacitor stores electric energy

They keep exchanging energy, creating large voltages inside the circuit.


🧪 LTspice Simulation of Resonance

To visualize this phenomenon, a series RLC circuit was simulated in LTspice using the following values:

  • R = 50 Ī©

  • L = 45 mH = 0.045 H

  • C = 1.36 μF = 1.36 × 10⁻⁶ F

  • AC source = 230 V

  • AC sweep = 100 Hz to 2000 Hz


šŸ”§ Circuit Explanation

The simulated circuit is a series RLC network.

All three components (R, L, and C) are connected one after another, and an AC source is applied across the combination.

The current through the resistor I(R1) is observed, which represents the current flowing through the entire series loop.


🧮 Resonant Frequency Calculation

Step 1: Multiply L and C

LC=0.045×1.36×106LC = 0.045 \times 1.36 \times 10^{-6}
LC=6.12×108LC = 6.12 \times 10^{-8}

Step 2: Square root of LC

LC=6.12×108\sqrt{LC} = \sqrt{6.12 \times 10^{-8}} LC=2.472×104\sqrt{LC} = 2.472 \times 10^{-4}

Step 3: Multiply by 2Ļ€2\pi

2Ļ€×2.472×1042\pi \times 2.472 \times 10^{-4}
2Ļ€6.2832\pi \approx 6.283
2Ļ€LC=0.001554

Step 4: Take reciprocal

f0=10.001554f_0 = \frac{1}{0.001554} f0643.7 Hzf_0 \approx 643.7 \text{ Hz}
f0644 Hz\boxed{f_0 \approx 644 \text{ Hz}}

šŸ“ˆ Verification from Simulation

At resonance:

  • XL=XCX_L = X_C

  • Net reactance X=0X = 0

  • Impedance Z=R=50Ī©Z = R = 50 \Omega

Current becomes:

I=VR=23050=4.6 AI = \frac{V}{R} = \frac{230}{50} = 4.6 \text{ A}

The simulation peak current is very close to 4.5–4.7 A, confirming perfect resonance behavior.


šŸ”š Conclusion

Resonance is a powerful condition in AC circuits where inductive and capacitive reactances cancel each other, leaving only resistance to oppose current flow. At this point, impedance is minimum and current reaches its maximum value.

Although the net reactance becomes zero, energy continuously oscillates between the magnetic field of the inductor and the electric field of the capacitor, leading to voltage magnification within the circuit. This phenomenon is the foundation of tuned circuits, filters, oscillators, and communication systems.

Understanding resonance completes the journey from resistance → reactance → impedance and opens the door to advanced AC circuit analysis.


Understanding Impedance — The Total Opposition in AC Circuits

In AC circuits, opposition to current is not as simple as resistance alone. When resistors, inductors, and capacitors work together, both magnitude and phase come into play.

This combined effect is called impedance, and it defines how AC circuits truly behave.


⚡ Impedance — The Total Opposition

Now, let’s combine everything.

When resistors, inductors, and capacitors are all connected in an AC circuit, the total opposition to current is called Impedance (Z).

Impedance includes both:

  • Resistance (R) — which is constant and frequency-independent.

  • Reactance (X) — which depends on frequency and causes phase shift.


šŸ“ Definition of Impedance (Phasor Form)

When working with AC signals, both voltage and current are sinusoidal and can be represented as phasors — rotating vectors showing both magnitude and phase.

The true definition of impedance is based on this phasor relationship:

Z = Ṽ / Ĩ

where:

  • = voltage phasor (magnitude + phase)

  • = current phasor (magnitude + phase)

Thus, impedance is a complex ratio that expresses both:

  • how strongly the circuit opposes current (magnitude), and

  • how voltage and current are shifted relative to each other (phase difference).

From this relationship:

|Z| = |Ṽ| / |Ĩ|
∠Z = ∠Ṽ − ∠Ĩ

This means:

  • The magnitude of impedance tells how much the circuit resists the flow of AC current.

  • The phase angle (∠Z) shows whether voltage leads or lags current, and by how much.


❗ Important Clarification

Impedance is not simply the ratio of instantaneous or RMS values:

  • ❌ Z = Vā‚šā‚‘ā‚ā‚– / Iā‚šā‚‘ā‚ā‚–

  • ❌ Z = v(t) / i(t) (instantaneous values)

  • ❌ Z = Vįµ£ā‚˜ā‚› / Iįµ£ā‚˜ā‚› — unless both are treated as phasors including phase information

✅ The correct and complete definition is:

Z = Ṽ / Ĩ

This phasor ratio accounts for both magnitude and phase, which is why impedance is a complex quantity, expressed as:

  • Z = R + jX (rectangular form)

  • Z = |Z| ∠ Īø (polar form)


🧮 Magnitude of Impedance

The magnitude of impedance is given by:

Z = √(R² + X²)

Here, X can be:

  • Positive → Inductive reactance (Xᓸ)

  • Negative → Capacitive reactance (−Xᶜ)

In phasor form, impedance is written as:

Z = R + jX

where:

  • j (or i) indicates a 90° phase shift


⚙️ Impedance of R, L, and C

  • Resistor:
    Zįµ£ = R (purely real, Īø = 0°)

  • Inductor:
    Zᓸ = jωL = j2Ļ€fL (purely imaginary, positive)

  • Capacitor:
    Zᶜ = 1 / jωC = −j(1/ωC) (purely imaginary, negative)

So, for a circuit containing R, L, and C:

  • Net reactance: X = Xᓸ − Xᶜ

  • Total impedance: Z = R + j(Xᓸ − Xᶜ)


šŸŽ›️ Frequency Dependence

This is where the magic happens:

  • Inductors: Reactance increases with frequency

  • Capacitors: Reactance decreases with frequency

  • Resistors: Unaffected by frequency

Because of this:

  • Inductors and capacitors are frequency-dependent components

  • Resistors are frequency-independent

This frequency-dependent behavior forms the basis of filters, oscillators, and resonant circuits — the heart of modern electronics.


šŸ”š Conclusion

Impedance is the complete description of how an AC circuit opposes current flow. It combines resistance, which dissipates energy, with reactance, which stores and returns energy through electric and magnetic fields.

While resistance determines how much current flows, impedance also tells us how voltage and current are phase-shifted, revealing the true dynamic nature of AC circuits. Its dependence on frequency is what enables filtering, tuning, resonance, and signal shaping in electronic systems.

Understanding impedance is a major step forward in electronics — it connects resistance, reactance, frequency, and phase into one powerful concept that brings AC circuits fully to life.

Understanding Reactance — Opposition to Change in AC Circuits

When we first learn about circuits, resistance feels like the only opposition to current. But as soon as we move into AC circuits, where voltage and current are constantly changing, a new concept comes into play — reactance.

In this blog, we’ll explore what reactance is, why it exists, and how it shapes the behavior of capacitors and inductors in AC systems.




⚡ What is Reactance?

When we first learn about circuits, we meet resistance — the opposition that limits how much current flows. But the moment we move from DC (Direct Current) to AC (Alternating Current), the story becomes much more interesting.

Here, the voltage and current are continuously changing, and this change introduces a new kind of opposition called Reactance.

Let’s explore what it really is, why it matters, and how it connects to a concept called Impedance — the total opposition in AC circuits.

In simple terms, reactance is the opposition that a capacitor or inductor offers to the flow of alternating current (AC).

It’s similar to resistance but with a key difference:

  • Resistance opposes all current, whether AC or DC.

  • Reactance only opposes changing current — the kind that goes up and down, like in AC.

When voltage and current are constantly varying, capacitors and inductors react to that change.

  • Capacitors store energy in the electric field.

  • Inductors store energy in the magnetic field.

Unlike resistors, these components don’t waste energy as heat. They temporarily store energy and return it to the circuit. This storage and return create a delay in current or voltage, and that delay is what we call reactance.


šŸ”§ Why is Reactance Needed?

In an AC system, voltage and current are not steady — they continuously rise, fall, and even reverse direction.

This constant change interacts with capacitors and inductors, which try to “resist” or “delay” the change due to how they store energy.

  • The inductor resists a change in current because it builds a magnetic field around itself.

  • The capacitor resists a change in voltage because it builds up an electric field between its plates.

This time-dependent opposition is exactly what allows us to design filters, amplifiers, and tuned circuits — all of which depend on reactance.


⚖️ Reactance vs. Resistance

So, we don’t use the same word “resistance” for both because:

  • Resistance dissipates energy as heat.

  • Reactance stores and gives back energy.

Their effects on current and voltage are fundamentally different.


šŸŒ€ Inductive Reactance — Opposition from a Coil

An inductor is simply a coil of wire that stores energy in a magnetic field when current passes through it.

But when you try to change that current, the inductor resists (thanks to Lenz’s Law).

The fundamental relation for an ideal inductor is:

V = L (dI/dt)

Where:

  • V = voltage across the inductor

  • L = inductance (Henry)

  • dI/dt = rate of change of current

This means the voltage depends on how quickly the current changes.

If the current changes fast, the voltage across the inductor becomes large.

Here’s what happens when AC is applied:

  • The inductor initially resists the change — it takes time to build a magnetic field.

  • The applied voltage goes into creating that magnetic field instead of immediately increasing current.

  • Once the current flows, it continues even as voltage starts to fall, because the inductor releases its stored energy.

This delay means current lags behind voltage by 90° in a pure inductor.

Inductive reactance is given by:

Xā‚— = 2Ļ€fL

Where:

  • f = frequency (Hz)

  • L = inductance (H)

So, as frequency increases, inductive reactance also increases.

That’s why:

  • For DC (f = 0), Xā‚— = 0 → acts like a short circuit.

  • For high-frequency AC, Xā‚— becomes very large → acts like an open circuit.


šŸ”µ Capacitive Reactance — Opposition from a Capacitor

For a capacitor, the voltage and current relationship is:

i(t) = C (dv/dt)

Where:

  • i(t) = current through the capacitor

  • v(t) = voltage across the capacitor

  • C = capacitance (Farad)

This equation shows that the current depends on how fast the voltage changes — not its actual value.

What really happens in AC:

  • As voltage begins to rise, charges start moving instantly — current begins flowing immediately.

  • It takes some time before enough charge accumulates for voltage to build up across the plates.

  • Hence, current reaches its peak first — when voltage is changing fastest.

  • Voltage reaches its maximum later — about a quarter cycle (90°) later.

Thus, current leads voltage by 90° in a pure capacitor.

Capacitive reactance is given by:

X꜀ = 1 / (2Ļ€fC)

So, as frequency increases, capacitive reactance decreases.

That’s why:

  • Capacitors pass high-frequency signals easily.

  • But they block DC (since f = 0 ⇒ X꜀ = ∞).


šŸ”„ The Two Types of Reactance

If you observe closely, they’re complete opposites in nature:

  • In an inductor, voltage leads current.

  • In a capacitor, current leads voltage.

  • Inductive reactance increases with frequency, while capacitive reactance decreases.

When both are present in a circuit, their effects can even cancel each other out — a concept known as resonance.


šŸ”š Conclusion

Reactance is a fundamental concept that explains how inductors and capacitors behave in AC circuits. Unlike resistance, which simply dissipates energy, reactance arises because energy is temporarily stored and returned through magnetic and electric fields.

Inductive reactance opposes changes in current, while capacitive reactance opposes changes in voltage. Their frequency-dependent nature allows engineers to design filters, oscillators, tuned circuits, and frequency-selective systems.

Understanding reactance is a crucial step toward mastering AC circuit analysis and leads naturally into deeper topics like impedance, resonance, and AC power systems.

Understanding Inductors and Inductance — How Magnetic Energy Is Stored

In electronic circuits, not all components respond instantly to changes. Some store energy and react over time. One such fundamental component is the inductor, which stores energy in a magnetic field and resists changes in current.

In this blog, we’ll understand what an inductor is, how it works, how it stores energy, and what inductance really means.



⚙️ What is an Inductor?

An inductor is a passive electronic component that stores electrical energy in the form of a magnetic field.
It mainly opposes changes in current — just like a capacitor opposes changes in voltage.

Whenever current starts flowing through an inductor, it generates a magnetic field around it.
And when that current changes (increases or decreases), the magnetic field changes too — which in turn induces a voltage that tries to oppose that change.

That’s the fundamental nature of an inductor.


🧱 Structure — How It’s Made

An inductor is typically made of:

  1. A coil of wire — usually copper, wound in loops or turns.

  2. A core — which can be air, iron, or ferrite placed inside the coil to enhance its magnetic properties.

  3. Two terminals / leads — for connection to the circuit.

The more turns the coil has, and the better the core material, the stronger the magnetic field it can create — and hence, the higher the inductance.


⚙️ How Does an Inductor Work?

Before any current flows:

  • There is no magnetic field around the coil.

When a voltage source is connected:

  1. Current starts flowing through the wire coil.

  2. As current flows, a magnetic field forms around the coil (according to Ampere’s Law).

  3. If the current keeps increasing, the magnetic field grows — but this change in magnetic flux induces an opposing voltage (back EMF) in the coil (as per Faraday’s Law of Electromagnetic Induction).

  4. This induced voltage always acts in the opposite direction of the applied voltage — this is Lenz’s Law in action.

So what’s happening inside is that the inductor resists any change in current.

  • If you try to increase current, it generates a voltage that opposes the increase.

  • If you try to decrease current, it generates a voltage that tries to keep it flowing.


šŸ’” In Simple Words

  • Capacitor → opposes change in voltage

  • Inductor → opposes change in current


šŸ”‹ Energy Storage in an Inductor

An inductor stores energy in the magnetic field created by the current flowing through it.

The moment you disconnect the source, this magnetic field collapses and releases energy back into the circuit.

The energy stored is given by:

E = ½ L I²

where:

  • E = energy stored (joules)

  • L = inductance (henries, H)

  • I = current through the inductor (amperes)

Just like a capacitor stores energy in an electric field, an inductor stores it in a magnetic field.


🧮 What is Inductance?

Inductance is the ability of an inductor to store magnetic flux per unit current.

In simple terms, it tells how much magnetic field (or magnetic flux) an inductor can produce for a given current flowing through it.

It is denoted by L and measured in Henries (H).

Mathematically:

L = NΦ / I

where:

  • N = number of turns in the coil

  • Φ = magnetic flux linked with the coil (Weber)

  • I = current through the coil (amperes)

It basically tells us how much magnetic flux is produced for a given current.


⚡ Voltage–Current Relationship

The voltage across an inductor is given by:

V = L (dI/dt)

This means:

  • If the current changes rapidly, the induced voltage is large.

  • If the current is steady, dI/dt = 0, so the voltage across the inductor is zero.

Once fully energized with DC, an inductor behaves like a short circuit.


🧠 Factors Affecting Inductance

  1. Number of Turns (N): More turns → higher inductance

  2. Core Material: Iron or ferrite cores concentrate magnetic flux → higher inductance

  3. Cross-sectional Area (A): Larger area → stronger field → higher inductance

  4. Length of Coil (l): Longer coil → weaker field → lower inductance

For a solenoid:

L = (μ N² A) / l

where:

  • μ = permeability of the core material

  • N = number of turns

  • A = cross-sectional area

  • l = length of the coil

Here, μ (mu) plays a similar role as ε (epsilon) in capacitors — it tells how well the core supports the magnetic field.


🧩 Summary Table



šŸ”š Conclusion

An inductor is a fundamental passive component that stores energy in the form of a magnetic field and resists changes in current. By generating an opposing voltage whenever current changes, inductors play a critical role in controlling current flow in electronic circuits.

Inductance defines how effectively an inductor can store magnetic energy, and it depends on physical factors like the number of turns, core material, and coil geometry. Inductors are widely used in filters, power supplies, energy storage systems, and signal processing circuits.

Understanding inductors and inductance provides a strong foundation for learning AC circuits, RL circuits, transformers, and advanced analog electronics.

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