AC Generator - Parts, Works, Function, Diagram

AC Generator - Definition, Parts, Works, Function, Diagram

Edited By Vishal kumar | Updated on Jul 22, 2025 08:20 AM IST

The AC generators have a big impact on the current electrical framework. The process of converting mechanical energy into electrical energy is the fundamental concept behind many electronic applications. In this article, we will explore what is an AC generator, its diagram, the working principle of AC generator, the construction and components, types of AC generators, applications in the real-life world, and their advantages as well as disadvantages. You can find the complete AC generator notes for class 12 here.

This Story also Contains

What is AC Generator?
Definition of AC Generator Class 12
Detailed Explanation of AC Generator Working
Construction of AC Generator
AC Generator Principle And Functioning Class 12
Types of AC Generators
Advantages And Disadvantages Of AC Generators over DC Generators
Applications of AC Generators Class 12
Difference Between AC Generator And DC Generator

ac generator

What is AC Generator?

An AC generator is a machine that converts mechanical energy into electrical energy. Based on power supply, generators are usually divided into AC and DC types. For a DC manufacturer, the mechanical supply is one direction, and the opposite applies to an AC manufacturer. These differences in input delivery vary developers' internal performance.

AC Generater digrame

This article will discuss the AC generator, its construction, how the EMF is drawn, its components and use, and much more. Roller rings are used in AC to produce alternating current in the machine. The electricity generated or current begins to switch between both types of generator.

Definition of AC Generator Class 12

A generator that converts the power of a machine into an electric current from a current output or a voltage source is known as an AC generator. This machine operates under Faraday's law of Electromagnetism. Here, the Direct Current voltage is generated by rotating inside a fixed coil, like a large power generator producing AC.

By applying Fleming's right-hand rule, the index of current changes in productivity is determined.

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Detailed Explanation of AC Generator Working

An AC generator creates an alternating current that periodically reverses direction. But in a DC generator direct current flows in one direction. The two ends of the coil are attached to the commutator which balances charges to and from the generator, thus resulting in a current that does not alter direction.

To get a better understanding of an AC generator working, let's consider an AC generator diagram with a simple loop generator installed under the influence of a magnet.

Construction of AC Generator

Here is a list of parts of the AC generator shown in the AC generator diagram, including the yoke, permanent magnets, coils or wires for wires, pole section, arm, pole shoe, slip rings, and brushes. The frame that serves as the protective cover of the generator is known as the yoke. All of the above are within the yoke. Magnets produce magnetic fields. The four-wire coil AB, BC, CD, and DC is housed inside the magnet.

The armature flux causes the production of an arm cell. Surgery is performed smoothly, using smooth rings. The rings are attached to the brush where it passes now. As the sliding rings pass smoothly on the brushes, they prevent twisting of the wires. Let's discuss the parts of AC generator in detail:

Armature: ABCD is a rectangular armature coil in which a large number of turns of insulated copper wire are coiled around a laminated soft iron core.
Magnetic Field: The armature coil rotates in the effect of a strong electromagnet which is of order 1-2 Tesla. N and S are the north and south poles of the electromagnet
Slip Rings: R₁ and R₂ are the two metallic rings which rotate with the rotation of coil. They are connected to the ends of the armature coil.
Brushes: B₁ and B₂ are the two carbon rods which are fixed in a position. They are connected with the two slip rings. The brushes allow the current to pass from the armature coil to the external resistance.

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The detailed AC generator diagram is given below to understand the components and workings of the AC generator clearly.

AC Generator Parts and Function

AC Generator Principle And Functioning Class 12

The working principle of AC generator is based on electromagnetic induction. It is the process of producing and generating an induced current in a coil by altering its orientation (i.e. it is rotated in a uniform magnetic field).

A loop is attached to a magnetic field called ABCD; as mentioned earlier in the AC generator diagram, the wire loop is called AB, BC, CD, and DC. With the help of an external shaft that acts as the main shaft, the loop is rotated.

The magnetic flux lines will run from left to right and from the north pole to the south pole. With the help of a shaft, the loop rotates as it cuts off the magnetic field. This improves the EMF, which makes the current flow through the conductors. With the help of Fleming's right-handed law on generators, the current

Fleming's right-hand rule gives the direction of current flow. The right hand is held with the thumb, index finger, and middle finger mutually perpendicular to each other index is determined.

The loop rotates; the law determines the current direction within wire AB. With a half cycle, the current flows into the AB wire. With the loop around the loop, the current inside the AB loop goes back to another loop. The same process is performed for other cables.

Slide rings are attached to the end of the loop and are responsible for the movement of the strings as the loop is rotated. It now passes through the slip ring to the brushes and is loaded as it passes through the smoothness of the brushes.

Throughout the half-cycle of the loop, the current direction is changed. By using a galvanometer, we can see the current exchange at the end of the load. This is how a current alternating generator generates a variable or current voltage.

Types of AC Generators

(i) Single Phase AC Generator

It produces alternating current with a single current waveform.
The construction is simple which makes it easier to operate.
It is less expensive due to the modest design.
Commonly used in household appliances which require small power loads.

(ii) Three-Phase AC Generator

It produces alternating current with three current waveforms which are 120 degrees apart.
They have complex construction due to additional components for maintaining three phases.
It is more expensive due to the complex setup.
Widely used in large industrial power-scale applications due to higher capacity.

Advantages And Disadvantages Of AC Generators over DC Generators

Advantages:

Generation of AC is much cheaper than DC
Most of the AC machines do not require high maintenance.
Voltage can be increased or decreased easily.
AC can be easily converted into DC.
AC generators are easy to transmit over long distances.

Disadvantages:

AC requires insulation as the peak value of AC is high.
Electrolytic processes like electroplating can not be performed using AC.
AC generators require transformers to step up or step down voltages.
AC has more losses than DC.
AC generators are less durable compared to DC generators

Applications of AC Generators Class 12

1. AC generators are used in hydropower plants and wind turbines to produce electrical energy using natural resources.

2. They are used in large-scale industries to supply power to heavy equipment.

3. AC generators are used in ships for electrical needs.

4. AC generators are also used in household appliances like refrigerators and washing machines.

5. They are used in power plants for the conversion of electrical energy from mechanical energy.

Difference Between AC Generator And DC Generator

The difference between ac generator and dc generator are given in the table:

AC Generator	DC Generator
Produces AC current	Produces DC current
Uses slip rings	Uses commutator
Output voltage varies	The output voltage is constant
Low maintenance	High maintenance
Alternating power supply	Constant power supply
Less expensive	More expensive
Efficient for long distances	higher losses during long distance

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Transformers

Frequently Asked Questions (FAQs)

1. What is the principle of ac generator? State the principle of ac generator

According to Faraday's law of electromagnetic input, the Ac generator is operational.

As the coil rotates, it undergoes change in the magnetic flux. According to Faraday's law of electromagnetic induction, electrons are transmitted by an EMF embedded in a coil that generates electricity generation. The circuit is closed with a load (lamp), where the current is interacted with the environment as the flow changes naturally.

The rotating coil is known as the rotor, and the field pillars as the stator.

But in reality, Ac generators or alternators are designed in such a way that the rotating part (Rotor) is a magnetic field. Conversely, the coil is stationary (stator) of the machine.

2. What is the use of an Ac generator?

The use of Ac generators is a very widespread feature in many applications such as, In cars, there they are known as alternators power generation from wind turbines power generation from hydroelectric dams Ac generators have usually many significant advantages over given DC Generators:

The design is simple.
Maintenance costs are low.
Loss is minimal
The size of the machines is consistent.
Ac generators are cheaper to produce

It is easy to go up and down the power generated by an Ac generator with the help of transformers

These are the definitions that Ac generators are the most advanced technology in many systems.

3. What is an Ac generator class 12?

An alternating current generator is a device that produces a potential difference. A simple ac generator consists of coil of wire rotating in magnetic field. The Ac generator installation is powered by steam turbines, electric turbines and fire engines. The output is an alternating current with current and current.

4. How does an Ac generator generate electricity?

Ac generators operate according to the Faraday law. As the armature rotates between the poles of the magnet on the axis directly facing the magnetic field, the coordination of the armor varies continuously. As a result, the emf is inserted into the armature. As a result, electrical power enters through a galvanometer and slippery brushes and brushes.

5. What are the factors that EMF produced in another alternator depend on?

The EMF produced depends on the number of armature coil turning, the magnetic field, and the speed of the rotating field.

6. What are the other advantages of Ac generators over DCs?

Ac generators can be easily upgraded and lowered with converters. The loss of Ac generators is very small compared to DC equipment.

7. What is an AC generator and how does it work?

An AC generator, also known as an alternator, is a device that converts mechanical energy into electrical energy in the form of alternating current (AC). It works on the principle of electromagnetic induction. When a conductor moves through a magnetic field, or when a magnetic field changes around a conductor, an electromotive force (EMF) is induced in the conductor. In an AC generator, a coil of wire rotates in a magnetic field, causing the magnetic flux through the coil to change continuously, which induces an alternating voltage in the coil.

8. Why does an AC generator produce alternating current instead of direct current?

An AC generator produces alternating current because of the continuous rotation of the coil in the magnetic field. As the coil rotates, the direction of the induced current changes periodically. When the coil is parallel to the magnetic field lines, no current is induced. As it rotates, the current increases to a maximum, then decreases back to zero, reverses direction, and repeats the cycle. This periodic change in current direction results in alternating current.

9. What is the role of slip rings in an AC generator?

Slip rings in an AC generator are continuous conducting rings that maintain electrical contact between the rotating coil and the external circuit. They allow the alternating current generated in the rotating coil to be transmitted to the stationary external circuit without interruption, even as the coil continues to rotate.

10. How does the frequency of AC produced by a generator relate to its rotation speed?

The frequency of AC produced by a generator is directly proportional to its rotation speed. The relationship is given by the equation f = NP/120, where f is the frequency in Hz, N is the rotation speed in rpm (revolutions per minute), and P is the number of magnetic poles in the generator. This means that increasing the rotation speed or the number of poles will increase the frequency of the AC output.

11. How does the concept of magnetic permeability affect the design of AC generators?

Magnetic permeability is a measure of how easily a material can be magnetized. In AC generator design, materials with high magnetic permeability, such as iron or certain alloys, are used in the core of the electromagnets and in the rotor. These materials concentrate and strengthen the magnetic field, increasing the efficiency of the generator. Higher permeability allows for stronger magnetic fields with less input energy, leading to more efficient power generation.

12. How does Faraday's law of electromagnetic induction apply to AC generators?

Faraday's law of electromagnetic induction is the fundamental principle behind AC generators. It states that the induced electromotive force (EMF) in a closed circuit is equal to the negative rate of change of magnetic flux through the circuit. In an AC generator, as the coil rotates in the magnetic field, the magnetic flux through it changes continuously, inducing an EMF. The faster the change in magnetic flux (due to faster rotation or stronger magnetic field), the greater the induced EMF.

13. How does the concept of magnetic flux relate to the operation of an AC generator?

Magnetic flux is a measure of the total magnetic field passing through a given area. In an AC generator, the coil rotates in a magnetic field, causing the magnetic flux through the coil to change continuously. This changing magnetic flux is what induces the electromotive force (EMF) in the coil, according to Faraday's law of electromagnetic induction. The rate of change of magnetic flux determines the magnitude of the induced EMF.

14. What is the significance of Lenz's law in the operation of an AC generator?

Lenz's law states that the direction of an induced current is such that it opposes the change that caused it. In an AC generator, this means that the induced current in the coil creates its own magnetic field that opposes the motion of the coil. This opposition is felt as a mechanical resistance to the rotation of the coil, which is why mechanical energy must be continuously supplied to keep the generator running. Lenz's law explains why energy must be input to generate electricity.

15. How does the number of turns in the coil affect the output of an AC generator?

The number of turns in the coil of an AC generator directly affects its output voltage. According to Faraday's law, the induced EMF is proportional to the rate of change of magnetic flux and the number of turns in the coil. Therefore, increasing the number of turns will increase the output voltage proportionally. However, it's important to note that this also increases the resistance of the coil, which can affect the current output.

16. What is the difference between a single-phase and a three-phase AC generator?

A single-phase AC generator has one coil or set of coils producing a single alternating current output. A three-phase AC generator has three coils or sets of coils, each producing an AC output that is 120° out of phase with the others. Three-phase generators are more efficient for power transmission and are commonly used in industrial applications, while single-phase generators are typically used for smaller-scale or residential applications.