More specifically, we can say that it is a waveguide that has the ability to transmit electromagnetic waves (in the form of light) at optical frequencies.

Structure of optical fiber

An optical fiber is basically a combination of core and cladding. Here, the core is a cylindrical dielectric composed of glass, through which light propagates and it is enclosed in a plastic cladding.

The figure below shows the structure of an optical fiber:

The whole assembly is surrounded by an elastic jacket in order to protect the fiber.

It is noteworthy in the case of optical fibers that cladding does not participate in lightwave transmission as light only propagates through the core. But, in order to reduce the signal losses due to scattering, an optical fiber is necessarily a combination of the core as well as cladding.

The optical fiber is composed in such a way that the core refractive index must be more as compared to the cladding.

Propagation of light ray through an Optical Fiber

As we know that an optical fiber allows propagation of the signal in the form of light (i.e., photons). Now the question arises how light propagates through an optical fiber?

The answer to the above question is total internal reflection.

When light is allowed to transmit through an optical fiber then it travels through the core only, by experiencing continuous reflections from the cladding. These reflections are nothing but total internal reflections.

As we have already discussed in Total Internal Reflection, that it only occurs when light incident from a denser to a rarer medium with the angle of incidence more than the critical angle.

With such an angle of incidence, light propagates through the core by making successive reflections rather being refracted at the cladding.

As the core is a cylinder with a smaller diameter thus, an only small reflection of the light ray will take place and hence this causes the incident angle to be definitely greater than the critical angle.

Modes of Propagation in an optical fiber

When light travels along the fiber then it is obvious that will transmit down the core by taking either single or multiple paths. So basically modes are nothing but the number of paths a light ray takes during propagation along the fiber.

There exist basically two modes of propagation through an optical fiber:

• Single-mode fiber: In single mode fiber the light ray is propagated along the fiber only by taking single (one) path.

So, due to the transmission of the wave due to only one path, the level of signal distortion at the time of transmission is also reduced. This is so because light rays do not transmit through multiple paths hence fidelity of signal at a longer distance is also maintained.

As the diameter of the core is small thus it requires a sharp light beam for which majorly laser light source is utilized.

• Multimode fiber: In multimode fiber, the core diameter is comparatively large as compared to that of the single mode fiber. As here, the fiber allows light ray propagation through multiple paths inside the core.

Here, the chances of signal dispersion and attenuation are more than that of single-mode fiber. At the same time, the broader core diameter permits several propagating paths for the light waves.

What are glass fibers?

Glass is basically an amorphous solid that is generally hard, transparent and brittle in nature. It is composed by melting and quenching several materials. Glass is a material that does not hold a well-defined molecular structure rather it has an arbitrary arrangement of molecules.

Let us have a look at the tabular representation of glass forming substance:

Glass exhibits a special characteristic, that if the composition of the material is changed, then the properties of the material also varies.

Advantages of Optical fiber

1. Lightwave transmission through an optical fiber enables distortion immune signal propagation.
2. Optical fibers permits secured as well as long distance transmission.
3. These cables serve for longer durations as compared to any other transmission cable.

Disadvantages of Optical fiber

1. The installation, as well as maintenance cost of optical fibers, are somewhat large.
2. Due to their fragile nature, it needs more protection from environmental conditions.
3. Though less distortion can transmit a signal to large distances, that requires the use of repeaters at the time of signal transmission.

Usually, fibers are made from silica as it provides better operating characteristics.  Also, silica is chemically stable material and can be employed for use in the harsh environment also. The use of silica is more appropriate in case of optical communication.

The post Optical Fiber appeared first on Circuit Globe.

The refractive index of the core is somewhat more as compared to that of the cladding. However, it is to be noted here that at the core-cladding interface the refractive index shows sudden variation.

The figure given below shows the step index fiber with its refractive index profile:

When light ray propagates along the step index optical fiber then it follows a zigzag path. However, these zigzag patterns are totally composed of straight lines due to total internal reflection.

Mathematically, the refractive index of step index fibre is given as:

: a is the core radius

r is the radial distance

Modes of Step index fiber

Step index single mode fiber

In step index single mode fiber, the core diameter is extremely small, that it allows only one mode to propagate through it. This means that only single light ray propagates through the step index fiber. Due to this the transmitted ray does not experience distortion due to delay differences.

The figure given below shows the propagation of light ray through step index single mode optical fiber:

Here we can clearly see that the diameter of the core is extremely narrow. Due to this, only a single mode propagates down the fiber. Here, the core size lies somewhere between 2 to 15 micrometre.

Step index multimode fiber

In step-index multimode fiber, the diameter of the core is sufficiently large that it allows multiple modes to propagate through it. This simply means that several light rays can propagate down the fiber in case of step-index multimode fiber.

Here, due to the propagation of multiple light rays simultaneously, the fiber experiences distortion due to delay in propagation time.

The figure given below shows the propagation of light rays through step-index multimode optical fiber:

Here, the above figure clearly shows that the diameter of the core is large enough that it allows multiple propagating paths. In this case, the core size lies nearly between 50 to 1000 micrometre.

It is to be noted in case of the step index fiber that the variation in index is given as:

Majorly the light source used in these fibers is light emitting diodes.

Advantages of Step Index Fiber

1. The manufacturing of these fibers is quite easy.
2. It is inexpensive.
3. The propagation takes place through total internal reflection.

Disadvantages of Step Index Fiber

1. In these fibers, as only one light ray propagates through the fiber at a time then it somewhat leads to a drawback in terms of its capacity to carry information signal.
2. Also due to the small diameter of the core, coupling the light inside it is somewhat difficult.

Applications of Step Index Fiber

These optical fibers majorly find its applications in local area network connections. The reason for this is that it has less information transmitting capacity as compared to graded index fiber.

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Basically, when a light ray is allowed to pass through the fiber then there are some chances that it may get reflected back. So, to avoid backward reflection of transmitted signal optical isolators are used.

It is also known as optoisolator, photocoupler etc. These are majorly used in laser applications. Due to this, the coherence of light does not get affected.

Components of Optical Isolator

The device consists of mainly 3 components namely, input and output polarizer it can be 2 input and output birefringent plate that acts as a polarizer and a Faraday rotator.

The whole operation of the isolator relies on these three components. Now, let us move further and understand the major types of the optoisolator.

Types of Optical Isolator

An optical isolator is majorly classified into the following categories:

These are mainly categorized on the basis of their polarization characteristics.

Polarization dependent isolator: A polarization dependent isolator is composed of mainly input and output polarizer along with Faraday rotator. These are mainly used in free space optical system as the system maintains the polarization of the source.

Polarization independent isolator: A polarization independent isolator is composed of input and output birefringent wedges along with Faraday rotator. It basically consists of 2 collimators. As firstly, at the time of transmission the beam gets splits and then merged afterwards thereby focusing at the other collimator.

But in the reverse direction, the ray gets split after which it gets diverge and hence not get focused at the collimator on the other side.

Working principle of Optical Isolator

As we have already discussed that it is basically used to direct the transmitted radiation in a single direction by avoiding the chances of backward reflection.

So, let us understand how this happens:

The figure below shows the design of the isolator consisting of 3 components:

Let us now understand how it operates:

As we can see in the figure shown above that the first component is input polarizer. So, light ray on passing through this polarizer gets vertically polarized. This vertically polarized light then fed to a Faraday rotator.

Faraday rotator is nothing but an optical device that rotates the polarization of light because of Faraday effect. It is to be noteworthy here that this effect is non-reciprocal and it is based on magneto-optic effect.

In the case of the optical isolator, the rotation angle of Faraday rotator is 45°. As we have already mentioned in the previous paragraph that it is non-reciprocal that means it simply rotates in a single direction.

After the light ray undergoes a rotation of 45°, then it is allowed to leave through the polarizer placed after the rotator i.e., the output polarizer. The polarizer at the output either absorbs or reflects the light but that relies on the type of polarizer.

Now, let us understand how the light ray does not get reflected by using the same arrangement.

The light absorbed at the output polarizer is allowed to fall at the Faraday rotator. The figure below represents the arrangement when the light is again reflected towards the rotator.

The rotator now rotates the light ray again by 45° in a non-reciprocal manner i.e., in a clockwise direction. After this rotation, the light ray gets horizontally polarized as we can see in the figure shown above.

But, the input polarizer is basically a vertical polarizer. So, the horizontally polarized light will get rejected by the vertical polarizer.

Hence, in this way, no any light ray will get scattered or reflected back at the input by using these 3 components.

This is an optical isolator works.

Applications of Optical Isolator

1. In the optical communication system: These finds wide applications in optical fiber communication system. As at the time of signal transmission, these devices reduce the chances of signal losses due to reflection.
2. In the optical amplification unit: An amplifier boosts the signal level so if we use an isolator along with an amplifier then it will result in better amplification of the transmitted signal.
3. In laser diodes: The laser light source is used to provide a highly coherent light wave. So, when it will be used with an isolator then the chances of having highly coherent radiation will become more.

So, from the above discussion, we can conclude that an optical isolator is one of the major devices used at the time of optical communication.

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More specifically, we can say that it is the process by which an electrical signal that contains message is converted into a light signal.

Basically, there exist two different methods of modulating the optical signal. These two methods are classified as:

Direct Modulation

As the name itself is indicating that it is a modulation technique in which the information that has to be transmitted is directly placed over a light stream emitted by the source.

In this method, simply the driving current of the light source i.e., the laser is changed directly with the electrical information signal in order to generate a changing optical power signal. So, it does not require individual optical modulators for the modulation of the optical signal.

In this modulation technique, the major drawback is associated with the carrier lifetimes of spontaneous and stimulated emission along with photon lifetime of the source.

While performing direct modulation with the laser transmitter, the laser turns on and off according to the electrical signal or the driving current. But, in this case, the laser linewidth somehow gets widened. This widening of laser linewidth is known as chirp. Due to this reason, direct modulation technique becomes unsuitable for data rates above 2.5 Gbps.

External Modulation

In external modulation, separate optical modulators are used that performs the modification of optical signals in order to change the signal characteristics.

It is basically used to modulate the signals having data rates of more than 10 Gbps. However, there is no any compulsion to use this method only for high data rate signals.

The figure below shows the operational technique of external modulator:

Here, the first block represents the light source which is basically a laser diode. After the diode, an optical modulator circuit is present that modulates the light wave emitted by the source according to the electrical signal.

The laser diode produces an optical signal of constant amplitude. So, in this case, the electrical signal instead of changing the amplitude of the optical signal varies the power level of the optical signal. Hence, at the output of the modulator, a time-varying optical signal is generated.

It is to be noted here that the circuitry of the external modulator can be integrated combinely with the optical source or it can be considered as an individual device.

Basically, optical modulators are of two types:

Electro-optical phase modulator

It is also known as Mach Zehnder Modulator and is composed of lithium niobate as its basic material. The figure below shows the operational method of electro-optical external modulator:

Here, a beam splitter and beam combiner are used to split and combine the light waves.

In this method, when an optical signal enters the modulator then the beam splitter splits the light beam into two halves and allows it to transmit through two different paths. Then the applied electric signal changes the phase of the light beam in one of the paths.

The light waves after transmitting through two different paths reach the beam combiner in order to recombine. This recombination of the two light beams can be constructive or destructive in manner.

When constructive recombination of the beams takes place then at the output of the modulator a bright light wave is achieved. This is shown by pulse 1 at the output. As against, when destructive recombination of the light beams takes place then the two halves cancel each other and thus no light signal is achieved at the output. This is shown by pulse 0 at the output.

Electro-absorption modulator

This modulator is basically composed of indium phosphide. In this type of modulator, the electrical signal containing information varies the properties of the material of light propagation. So, according to the variation in the property either pulse 1 or 0 is achieved at the output.

It is to be noted in electro-absorption modulator that, one can integrate this modulator along with a laser diode and enclose it in a standard butterfly package.

This reduces the space, power and voltage requirements of the device instead of using separate laser source and modulator circuit.

The post Optical Modulation appeared first on Circuit Globe.

Optical line terminal is abbreviated as OLT.

OLT do so by converting an electrical signal into an optical signal or vice versa in order to ensure proper flow of the information.

Usually by the use of OLT information can be transmitted and received up to a distance of 20 Km.

Working of Optical Line Terminal

OLT functions in such a way that it receives data or signal from long-haul or metro network and provides it to the users present in the PON. Also known as the flow of information in the downstream direction.

Likewise, the data from the long distant users are also accepted and distributed by the OLT.

It can manage one or more PON simultaneously.

The figure below shows an OLT that is handling 4 separate passive optical networks at the same time:

Here, each PON has individually 32 connections. Thus we can say a single OLT can provide the data or information to 128 users.

As we have already discussed that OLT offers a downstream and upstream flow of information. So, in case of downstream transmission, the network uses a wavelength of 1490 nm for both data and voice signal and 1550 nm wavelength of video signal distribution.

While, in the case of upstream flow, the wavelength of nearly around 1330 nm is used by PON for both voice and data signal.

Usually the Optical line terminal equipment operates at 155 Mb/s, 622 Mb/s, 1.25 Gb/s or 2.5 Gb/s.

Optical Network Termination

As we have already discussed that an optical line terminal equipment is present at the central office. But optical network terminal, abbreviated as ONT is situated at the user’s zone itself.

Its function is to establish optical connectivity between the network and end user. ONT has the ability to provide combined telecommunication services according to the needs of users at the endpoint.

An ONT can be a simple box present outside the house of the end user or it can be attached to an indoor electronic rack. When mounted in an electronic rack, it determines the receiving end of each of the multiplexed data. Thereby providing the originally transmitted information to the desired location.

Both OLT and ONT are the modules of the passive optical network. And are present in the network to ensure smooth transmission and reception of data or information.

An optical network unit is of similar use but, despite being placing it inside the user’s area like ONT, it is placed inside a shelter, near to the area of the user. More specifically we can say, it is placed in some centralized area within an office building.

As it is placed in an open region, thus it must be rugged enough so as to withstand environmental conditions such as temperature variations etc.

Also, the cabinet in which it is to be housed must be water resistant, windproof etc. in order to ensure proper protection.

Along with all this, a source of power must be provided to it for the proper functioning.

To establish a connection between ONU and customer area, coaxial cable or optical fiber link can be used.

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As against superconductors are the materials whose level of conduction is very higher than conductors as these materials possess quite high conductivity but at a specific temperature.

Here in this article, we will see other differences between the two using the comparison chart.

Content: Semiconductors Vs Superconductors

1. Comparison Chart
2. Definition
3. Key Differences
4. Conclusion

Comparison Chart

Basis for Comaprison	Semiconductors	Superconductors
Basic	These offer lower conductivity than conductors because of offering moderate resistivity.	The conductivity of superconductors is more than conductors due to zero offered resistance.
Energy Consumption	Moderate	Negligible
Current rating	It can only handle fixed level of current.	It can withstand very high value of current.
Conductivity range	Between conductors and insulators.	Conductivity is beyond conductors.
Band Gap	0.25 to 2.5 eV.	Above 2.5 eV.
Examples	Germanium, Silicon, etc.	Aluminium, Bismuth, Mercury, etc.

Definition of Semiconductor

Semiconductors are referred as the materials whose level of conduction is lower than conductors but more than insulators. This means semiconductors are neither good conductors nor good insulators. A pure semiconductor does not possess accurate conductivity, but by the addition of impurity to the pure semiconductor material somewhat greater conductivity is achieved.

The classification of semiconductors is based on the type of impurity-doped to the pure semiconductor to increase its conductivity. The semiconductors are of two types, p-type and n-type semiconductors. Also, with the addition of different types of impurity, the two semiconductors have a different type of majority and minority charge carriers.

Basically, a certain energy gap exists between the conduction band and the valence band. And for the current flow to take place the majority carriers must move from the valence band to the conduction band. This energy level separation is referred as bandgap.

For semiconductors, the bandgap is generally less than 2 eV thus, on gaining a sufficient amount of energy, the electrons move from valence to conduction band and results in the flow of current. With the increase in temperature, more energy is gained by the charged carriers resulting in more conduction and a decrease in resistance.

Definition of Superconductor

The materials that lose all its electrical resistivity below a critical temperature are known as superconductors. This means that below a specific temperature, superconductors allow the flow of current through them without any loss of energy. Thus, it is said that their conductivity at a certain temperature is more than normal conductors. These are regarded as the materials that possess zero resistivity at a certain temperature.

In normal conductors with the increase in temperature, the resistivity increases, so a decrease in temperature reduces the resistance. But at the lowest temperature, the resistivity possesses a specific value. Thus, the materials in which the resistivity suddenly attains zero value at a particular temperature are known as superconductors.

As these hold the ability to carry current with no resistance hence no loss of energy is associated with it.

In superconductivity, pair formation of electrons does not take place, however, highly correlated pairs of electrons exhibit superconductivity. Basically, in superconductors, highly strong interaction between two electrons in the lattice results in a high flow of current below the critical temperature.

Superconductors are mainly classified as Type I and Type II superconductors.

The Type I superconductors act as conductors at room temperature but after reaching critical temperature, the material allows an uninterrupted flow of current. However, the Type II superconductors are not at all good conductors at room temperature but once reaching the critical temperature, it attains superconductivity. Generally, metallic compounds and alloys exhibit superconductivity.

Conclusion

So, from this discussion, we can conclude that semiconductor and superconductor are the two classes of conducting materials that which are mainly categorized according to their level of conductivity.

The post Difference Between Semiconductors and Superconductors appeared first on Circuit Globe.

Both the voltage regulator circuits have their principle of operation thus have their own advantages and disadvantages which we will discuss in this article.

What is a Voltage Regulator?

A voltage regulator is a device that is used to maintain the output voltage at a constant value despite the variation in load current or input voltage. Its presence in electrical and electronic circuits is necessary as it tries to sustain the dc output voltage within a specified range irrespective of the variation in input voltage or load current.

Basically, an unregulated dc supply voltage is converted into regulated dc output voltage where the output voltage does not show significant variation. It is to be noted here that the control element is the major component of the circuit and its placement is different in the two types of regulator circuits.

Content: Shunt Vs Series Voltage Regulator

1. Comparison Chart
2. Definition
3. Key Differences
4. Conclusion

Comparison Chart

Basis for Comparison	Shunt Voltage Regulator	Series Voltage Regulator
Connection orientation	The control element is parallelly connection with the load.	There exists a serial connection between the control element and the load.
Voltage Regulation	Poor	Good
Circuit design	Simple	Quite complex
Type of control element	Low current, high voltage component.	High current, low voltage component.
Current through the control element	Only a small amount of current flows through control element.	The complete load current passes through the control element.
Preferred for	Fixed voltage operations as it does not suit varying load conditions.	Shows suitability towards both fixed and variable voltage operations.
Compensation in change in output voltage	By varying the current through the control element.	By adjusting the voltage across the control element.
Efficiency dependency	On load current	On output voltage
Example	Zener shunt regulator	Series feedback regulator

Definition of Shunt Voltage Regulator

The figure below shows the shunt voltage regulator:

It is clear from the above figure that the control element is parallelly connected to the load. Thus, it is called so.

Here the unregulated input voltage provides the load current. However, a part of the current flows through the control element present in the branch parallel to the load. This helps to maintain the invariable voltage at the load. Whenever the load voltage of the circuit varies then through the sampling circuit feedback signal is provided to the comparator. The comparator unit further makes a comparison between the feedback signal and the applied input.

The difference generated corresponds to the amount of current needed to be flowed through the control element to have constant load voltage.

Definition of Series Voltage Regulator

The below-given figure represents a series voltage regulator:

Here the control element is serially connected with the load. Hence is given the name series voltage regulator.

In the series voltage regulator, the control element is responsible for controlling the amount of input voltage that reaches the output. Thus, it is an intermediary element between the supplied unregulated input voltage and the output voltage. Like shunt regulators, here also a part of the output is fed back to the comparator through a sampling circuit where reference input and the feedback signal are compared.

So, on the basis of output generated from the comparator, a control signal is generated and it is further provided to the control element on the basis of which the load voltage is regulated.

Conclusion

Thus, the above discussion concludes that both shunt and series voltage regulators are used to regulate the voltage. However, the presence of a control element in the respective circuits leads to cause variation in the way the circuits operate.

The post Difference Between Shunt and Series Voltage Regulator appeared first on Circuit Globe.

In symmetric multiprocessing systems, all the processors present within the system are of identical nature and executes programs.
As against, in asymmetric multiprocessing, the processors present within the system are non-identical in nature where one of the processors instructs the other processors within the system to execute the desired task.

Before going through the detailed idea of symmetric versus asymmetric multiprocessing. Let us understand-

What is Multiprocessing?

The term multiprocessing corresponds to the use of two or more central processing units within a single computer system in order to execute tasks parallelly. Basically, multiprocessing enables the system to execute various parallel processes within a system and this is done by incorporating multiple processors inside a single computer system. However, it is not necessary that a system always has more than one processor as sometimes there exist single processors within the system as well.

Thus, it is not wrong to say that a system may or may not be a multiprocessor system. However, if a system has multiple processors, then each processor can execute independent processes.

It is to be noted here that the CPU is responsible for handling the arithmetic and logical functions as well as carrying out input/output operations. So, to perform this, either single or multiple processors are required.

Content: Symmetric Vs Asymmetric Multiprocessing

1. Comparison Chart
2. Definition
3. Key Differences
4. Conclusion

Comparison chart

Basis for Comparison	Symmetric Multiprocessing	Asymmetric Multiprocessing
Acronym	SMP	AMP
Basic	All the processors are identical and forms connection with a shared memory.	All processors are not identical as one behaves as master and rest others as slave, where each one holds own memory space.
Approach	Ready-queue	Master-Slave
Operating System	A single operating system can be accessed by each processor for task execution.	The master processor has the operating system within which all system calls are executed.
Design	Easy	Comparatively complex
Memory footprint	Less	Comparatively more
Self scheduling ability	Exist	Not exist
Communication overhead	Present	Not present
Processor architecture	Each individual processor has same architecture.	The processors may or may not have different architecture.
Overall Cost	High	Comparatively low
Suitable for	Homogeneous cores	Homogeneous or Heterogeneous cores
System routines	Easy	Quite difficult
Use	In general purpose systems	In embedded systems

Symmetric Multiprocessing

Symmetric Multiprocessing called SMP in short form is a type of multiprocessing system operation that uses multiple processors of the same configuration within a single system in order to execute multiple tasks. Here all the processors are of identical nature and are treated in an equal manner.

In this type, an operating system exists in memory and is accessible by all the processors within the system but not simultaneously. This means it is based on a shared operating system technique, called the floating master method. If multiple CPUs are required to run OS code, then the one which requested first will be able to execute first and till that time it will remain locked (called mutex) for the rest of the processors.

Asymmetric Multiprocessing

Asymmetric multiprocessing abbreviated as AMP is another type of multiprocessing technique that consists of multiple processors out of which one behaves as master and other than that one as slaves. The master processor is responsible for executing the operating system.

This technique allows concurrent running of several tasks on multiple processors. Its private memory holds the data structure which has the details for ready processes. Here if the master processor gets failed then one of the slave switches to perform the master processor operations.

Conclusion

From the above discussion, it is clear that SMPs are implemented on homogeneous cores i.e., the identical ones. While AMPs are implemented on homogeneous or heterogeneous cores i.e., non-identical ones. In SMP, system functions show dependency on load distribution thus, is not deterministic. Due to this reason, symmetric multiprocessing is not used in embedded systems.

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The electromagnetic flowmeters work on the principle that the obstruction is created in the path of the liquid and the pressure of the liquid induces the voltage across the coil.

Working Principle of Electromagnetic Flow Meter

The electromagnetic flowmeter works on the principle of Faraday’s Law of electromagnetic induction. This law states that when the conductive liquid passes through the magnetic field, the voltage induces across the conductor. The magnitude of the voltage is directly proportional to the velocity, length of the conductor and the strength of the magnetic field.

The magnetic field is generated by the coil which is mounted on the external metallic body of the pipe. The liquid acts as a conductor and when passes through the magnetic field induce the voltage across the coil. The magnitude of the voltage depends on the velocity of the liquid.

Construction of Electromagnetic Flow Meter

The electromagnetic flow meter consists the electrically insulated pipe made of fibre. Electrodes placed opposite to each other, magnetic coil placed on the pipe for generating the magnetic field etc. The insulated pipe carries the liquid whose flow needs to be measured.

The electromagnet is placed around the insulated pipe. This electromagnet induces the magnetic field around the pipe. The arrangement is similar to the conductor moving in the magnetic field. The voltage is induced across the coil because of the flow of the liquid. The induces voltage is expressed as,

Where, v – velocity of conductor (flow); m/s
l – length of conductor = diameter of pipe ;m
B = flux X density ; wb/m²

If the magnetic field around the pipe remains constant than the generating voltage is proportional to the velocity of the fluid.

Advantages of Electromagnetic Flow Meter

1. The output voltage of the electromagnetic flow meter is proportional to the flow rate of the liquid.
2. The output is uninfluenced by the varying characteristic of liquid like viscosity, pressure, temperature etc.
3. The electromagnetic flow meter can measure the flow of slurries, greasy, and can handle the corrosive fluid liquids.
4. It is used as a bidirectional meter.
5. The extremely low flow rate can also be measured by the electromagnetic flow meter.

Disadvantages of Electromagnetic Flow Meter

1. The electromagnetic flow meter has low accuracy.
2. It is heavy and extremely large in size.

The electromagnetic flow meter is also known as the magmeter.

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A charge is a component that contributes to electricity. On the contrary, mass is a component that contributes to gravitation.

We will discuss the various factors over which charge can be distinguished from the mass.

Content: Charge Vs Mass

1. Comparison Chart
2. Definition
3. Key Differences
4. Similarity
5. Conclusion

Comparison chart

Basis for Comparison	Charge	Mass
Basic	It produces electric field.	It produces gravitation field.
Classification	Positive and negative	Always positive
Denoted as	q	m
Nature	Quantized	Non-quantized
SI unit	Coulombs	Grams or Kilograms
Existing force	Attractive or repulsive	Attractive only
Conservation	Exist	Not exist
Dependency on speed	Independent	Dependent
Existence	Cannot exist without mass	Can exist without charge

Definition of Charge

A charge is defined as a property of matter. It is denoted by q and classified into two categories namely positive and negative. We know that atom is the smallest individual element that constitutes a matter. Also, according to the classification of charge, we can define charge as electron and proton. Basically, the property with which the two types of charges are differentiated is known as the polarity of charges.

The charges of the same polarity always repel each other as against charges of different polarities always exhibit attractive force. Sometimes we come across the word ‘point charge’, point charge corresponds to such charged bodies which are very small in size in comparison to the separation distance of charges.

Fundamental Properties of Electric Charge

• Additivity: For a system with ‘n’ individual charges, the total charge of the system will be the summation of each individual charge present within the system.
• Conservation: The total charge within a system is of conserved nature. This means that they may get redistributed i.e., can be transferred from one body to another but cannot be destroyed or created.
• Quantized: Charge always exists as an integral multiple of e. The charge on any body is given as:
  q = ne
  : e corresponds to the charge on an electron or proton.

Definition of Mass

Mass is known to be a fundamental property of matter. The mass of a body is the measure of the amount or density of atoms that a body consists of. Also, this measurement is independent of the place where the body is present and the applied gravitational field. Generally, mass is regarded as an unchangeable property of matter but with an increase in speed, mass of the moving body also increases. The relation between mass and moving velocity of an object is given as:

: m is the mass of moving body,

m_o is the mass of the stationary body,

c is the speed of light 3 * 10⁸ m/s

The mass of a body remains independent of the way particles is rearranged within the body.

Sometimes people get confused between the words mass and weight and use the two interchangeably. However, the two are different and there are various factors that differentiate mass and weight.

Similarities

Both charge and mass are known to be the properties of matter. Charge and mass can be added as real numbers, both have magnitude and no direction thus are scalar quantities.

Conclusion

Proton and electron are the two types of charges let us see what charge and mass both proton and electron hold. Proton is positive and has a charge of the magnitude of +1.6 * 10^-19 C and a mass of 1.67 * 10^-27. While electron is negative with a charge of magnitude -1.6 * 10^-19 C and mass of 9.11 * 10^-31.

This means the values of charge and mass are different.

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