Retrofit Emission Control Devices: Clean air is not just important. It is life. Every breath we take should be pure and safe. But sadly, the air around us is filled with harmful gases and tiny particles. These come from vehicles, factories, and other machines that burn fuel. One strong and smart solution to reduce this … Read more
What are Measuring Instruments? Measuring instruments are the tools that help us see and understand what’s happening inside an electric circuit. They show us things we can’t see with our eyes – like how much current is flowing or how much voltage is present. Now let’s understand their types. Types of Measuring Instruments There are … Read more
Compensating Winding When a motor or generator is working, the current inside the armature (the rotating part) keeps changing, especially when the load changes suddenly or becomes too heavy. These changes in current create something called a cross magnetizing effect, which means the magnetic field gets pushed to one side. Now imagine this — every … Read more
Armature Reaction – Definition When a motor or generator is running, there are two types of magnetic fields inside it. One magnetic field comes from the main field winding (which is supposed to be there), and the second one comes from the armature winding (the rotating part). Now, when the armature winding carries current, it … Read more
Commutation in dc machine Let’s imagine the heart of a DC generator — the armature — is always spinning. As it spins, the current in its wires keeps changing direction. That means it actually creates alternating current (AC), not direct current (DC) at first. But we call it a DC generator — why? That’s because … Read more
DC Shunt Generator A DC Shunt Generator is a special type of DC generator that is commonly used because it works on its own without needing any outside power to get started. It gives a stable voltage, whether you’re using it a little or a lot. Let’s understand characteristics of dc shunt generator how it … Read more
Types of Armature Winding When we talk about armature winding in electric machines (like motors or generators), we’re simply talking about how the wires are arranged inside the machine to carry current. These wires connect at a part called the commutator. Now, depending on how these wires are connected at the ends, armature winding is … Read more
A DC machine is an electromechanical device that converts electrical energy into mechanical energy, or vice versa, using direct current (DC). It works on the fundamental principle of electromagnetic induction, which was discovered by Michael Faraday. DC machines are classified into two main types: DC generators and DC motors. A DC generator converts mechanical energy … Read more
What is Transmission Line? A transmission line is like a big electric road. Just like trucks carry goods from one city to another, a transmission line carries electricity from power stations to our homes, schools, offices, and factories. Simple Example: Imagine a water pipe. Water flows through the pipe and reaches your tap. In the … Read more
Electrical Power Distribution System The distribution system is the part of the electric supply network that delivers electricity from the distribution substation to the end consumers (homes, shops, farms, etc.). An electrical distribution system is a network of equipment that carries electricity from high-voltage transmission lines to homes, businesses, and other users. It acts as … Read more
Measurement of Power in Three-Phase Systems A wattmeter is a device used to measure the average or real power in AC circuits. While the method for measuring single-phase power is discussed in Chapter 1, this section focuses on the measurement of three-phase power. There are three main methods used for measuring the active (real) power … Read more
ideal Voltage and Current Sources Electricity is a part of our daily life. We use it to light our homes, run our fans, charge our phones, and power our TVs. But have you ever thought — where does this electricity come from? That’s where voltage sources and current sources come in. Let’s understand them in … Read more
Open circuit and short circuit What is an Open Circuit? | An open circuit means there is a break or gap in the path where electricity should flow. Imagine a road where a bridge is broken — cars can’t pass through it. In the same way, when a wire or part of the circuit is … Read more
Introduction to Magnetic Circuits We all know that magnets can pull things like pins or nails. But have you ever wondered how this invisible pull works inside machines like fans, motors, or transformers? Well, it’s all about something called a magnetic circuit. Just like electric current flows in a loop through wires in an electric … Read more
Magnetic Hysteresis When we take a piece of magnetic material—like iron—and magnetise it first in one direction, and then in the opposite direction, something interesting happens. The magnetic strength inside the material does not follow the applied force exactly. Instead, it lags behind. This delay is called Magnetic Hysteresis. 🔄 What is Magnetic Hysteresis? Magnetic … Read more
Magnetic Flux Density Have you ever seen how magnets pull things without touching them? This invisible force spreads out in space like magic. But how do we measure this magnetic power in a certain area? That’s where Magnetic Flux Density comes in. 🌟 What is Magnetic Flux Density? Magnetic Flux Density is a way to … Read more
Definition of Parallel Plate Capacitor A parallel plate capacitor is a device made of two flat, conductive plates placed parallel to each other with a small gap between them. This gap is usually filled with air or a material called a dielectric. When we connect a battery or voltage source across the plates, one plate … Read more
what is magnetism? Long ago, people thought magnetism was a kind of magic. They didn’t understand how it worked, so they didn’t use it much. But as time passed and science grew, we learned the truth — magnetism is not magic, it’s a real and powerful force. Today, magnetism is one of the most important … Read more
Introduction to Capacitors: We all know that different objects can hold different amounts of electric charge, even when they are at the same voltage. This ability to store charge is called capacitance. To store a useful amount of charge, we use a special device called a capacitor. A capacitor is made of two metal plates placed close … Read more
Cylindrical Capacitor A cylindrical capacitor is made up of two round, hollow tubes that are placed one inside the other. These tubes are called cylinders. The space between them is filled with a special material that does not let electricity pass through—this is called insulation. One of these cylinders is in the middle—this is the … Read more
Capacitors in Series and parallel Let’s imagine you have three capacitors — we’ll call them C₁, C₂, and C₃.Now, we connect them one after another, like links in a chain. This is called a series connection. When we apply a voltage V across this whole chain, something interesting happens: Now, remember a simple rule:Q … Read more
Insulators Dielectric insulators are materials that do not let electric current pass through them easily. This is because they have almost no free electrons inside them. You can think of them like strong walls that stop electricity from going through. Under normal conditions—like regular voltage and temperature—these materials stay safe and do not conduct electricity. … Read more
Conductor Have you ever seen electric wires around you? They carry electricity from one place to another. But have you ever wondered how electricity flows through them so easily? The reason is electrical conductors. A conductor is a material that allows electricity to pass through it easily because it has lots of free electrons. These … Read more
Electricity Electricity is the movement of tiny particles called electrons from one place to another. This movement is also known as the flow of electric charge. Just like water flows through a pipe, electricity flows through wires or other materials. The speed and ease of this flow depend on the kind of material the electrons … Read more
Electric Current Electric current is the flow of tiny particles called electrons. Just like water flows through a pipe, electrons flow through wires. This flow is what we call electric current. We show electric current with the letter I, and its unit is called an ampere (A). You can think of it like measuring how … Read more
Caliper A caliper tool is a special tool used to measure things. It helps us find out the exact size of an object, like how long, wide, thick, or round it is. This tool is very useful when we need to be very accurate with measurements. Calipers are usually made of strong metals like high-carbon … Read more
Chisels A chisel is a very simple but powerful tool. It is mostly used to cut light and thin metal sheets. You can think of it like a strong metal stick that helps in cutting other metals. Chisels are made from high carbon steel. This steel is strong and tough, which makes the chisel strong … Read more
Hammer – The Helping Hand of the Workshop A hammer is one of the most useful and commonly used tools in any workshop. It is a strong hand tool that helps us do many different kinds of work. We use a hammer to: In simple words, jobs like hammering, bending, shaping, cutting, and joining are … Read more
What is Electrical Safety? Electrical safety rules mean staying safe when using electricity. It is all about using electric machines and wires in the right way so that no one gets hurt. Electricity is very useful. It helps us light our homes, run fans, charge phones, and do so many things. But if we do … Read more
what is Files? The process of removing unwanted material in the form of powder by rubbing a rough surfaced tool from the surface of a workpiece is called filing and the cutting tool used for this purpose is called file. With the help of sandpaper, we can remove excess material in the form of fine particles from plane … Read more
distinguish between centripetal force and centrifugal force What is Centripetal Force? To make anything move, we need to use force. Just like you push a toy car to make it roll or pull a cart to make it move, force helps things start moving. But not all movements are the same. Some objects move in … Read more
What is Circular Motion? Circular motion means moving around in a circle. When something goes round and round on the same path, we call it circular motion. Think about the hands of a clock, a fan spinning on the ceiling, or the wheel of a bicycle. They all move in a circle. That’s circular motion! … Read more
Introduction Friction is a force that tries to stop things from sliding or moving when they touch each other. It always works in the opposite direction of the push or pull that’s trying to move something. So, if you try to slide a box forward, friction pushes back. It only happens when two surfaces touch, … Read more
Non-Polarized Capacitors A capacitor is a small but very useful part used in many electrical and electronic devices. It has two ends (or terminals) and its main job is to store energy in the form of electricity. Think of it like a tiny battery that can charge and discharge quickly. Capacitors come in different shapes, … Read more
Introduction Capacitors are small parts used in electronic devices. They help store energy and manage how electricity flows. Think of a capacitor like a tiny battery that charges and discharges quickly. In many circuits, they are used to clean up signals, reduce sudden changes in power, and give a quick boost of energy when needed. … Read more
Fan Capacitors Electric fans are all around us. We use them in our homes, offices, factories, and even inside cars, trains, and computers. They help move air to keep us cool or to keep machines from overheating. Depending on how they get power, electric fans are mainly divided into three types: AC fans, DC fans, and AC/DC fans. … Read more
What is a Wirewound Resistors? A wirewound resistors is a small, strong part used in electrical circuits. Its main job is to control the flow of electric current -kind of like a traffic signal for electricity. Inside this resistor, there is a thin metal wire. This wire is wrapped around a solid core made of … Read more
relation between electric field and potential What is an Electric Field? Imagine a charged object, like a balloon rubbed on your hair. Around it, something invisible forms — a kind of invisible space where other charges can feel a push or a pull. That invisible space is called an electric field. It’s like the area … Read more
What is Ohm’s Law? State Ohm law Ohm’s Law helps us understand how electricity moves through wires and other materials. It shows the connection between three important things: Voltage (V), Current (I), and Resistance (R). A long time ago, a scientist from Germany named Georg Simon Ohm discovered this simple but powerful rule. He found … Read more
Kirchhoff Law Class 12 Kirchhoff gave two laws to solve complex circuits, namely ; Kirchhoff Current Law ( KCL ) or Kirchhoff First Law Kirchhoff Current Law is a basic and very important rule in electricity. It helps us understand how electric current flows in a circuit. This law is about junctions in an electrical … Read more
