Category: Physics Notes PPT

The term ultrasonics is said to be the vibrations of frequencies which is greater than the upper limit of the audible range for humans that is greater than about 20 kilohertz. The term sonic is said to be applied to waves that are ultrasound of very high amplitudes. The hypersound which is sometimes known as praeter sound or the microsound is the waves of sound of frequencies that is greater than 1013 hertz. 

At such a high level of frequencies, i.e a frequency of about 1.25 × 1013 hertz, it is very difficult for a wave of sound to propagate efficiently. It is impossible for the longitudinal waves to propagate at all even in a liquid or a solid. That is because the molecules of the material in which the waves are traveling that cannot pass the vibration along rapidly enough.

Ultrasonic Machine

Ultrasound is the wave of sound with frequencies that is higher than the upper audible limit of human hearing. The ultrasound is not different from “normal” that is the audible sound in its physical properties. Except that humans cannot hear it. This limit is said to vary from person to person and is approximately 20 kilohertz that is written as 20,000 hertz in healthy young adults. The devices that are the ultrasound devices operate with frequencies from 20 kHz up to several gigahertz.

Ones is used in many different fields. The term that is ultrasonic devices that are used to detect objects and measure distances. By imagining the ultrasound or sonography is often used in medicine. In the nondestructive testing which is of structures and products. The ultrasound is said to be used in detecting invisible flaws. 

Industrially the term that is ultrasound is used for cleaning, and mixing, and accelerating processes that are chemical. Animals such as bats generally use ultrasound voice for locating prey and obstacles as well.

The term that is acoustics which is the science of sound starts as far back as Pythagoras in the 6th century BC who wrote on the properties which are the mathematical properties of stringed instruments. In 1794 echolocation which are in bats was discovered by Lazzaro Spallanzani when he demonstrated that bats hunted and navigated by inaudible sound. In 1893 Francis Galton invented the Galton whistle that is an adjustable whistle that produced ultrasound which he used to measure the hearing range of humans and other animals as well. This was demonstrating that many animals could hear sounds above the hearing range of humans. In 1917 the first application of the technology of ultrasound was an attempt to detect submarines by Paul Langevin. The effect, which is known as piezoelectric, was generally discovered by Jacques and Pierre Curie in 1880 which was useful in transducers to generate and detect ultrasonic waves in air and water.

Ultrasonic Frequency

The term that is sounds with a frequency of 20 kHz and higher are said to be referred to as ultrasound or we can say ultrasonic sound. We can say that the high frequency sound is sound of which the frequency lies between 8 and 20 kHz. The sound which is the high frequency sound with a frequency over 16 kHz can hardly be heard but it is not completely inaudible. The sound which is the high frequency sound and even ultrasound in the lower frequency zone that is up to 24 kHz can be audible if the sound level is high enough. The sound that threshold is the level of the sound where sound can be perceived that usually rises sharply once the frequency and therefore the tone) becomes higher. A person who is younger  hears high frequency sound better and their hearing range is greater toward the high frequencies.

The term that is ultrasound and sound of the frequencies that are of high range are widely applied in the industry and health care and also in movement detectors, the range finders and remote controls as well. We can notice that typical for these applications is that their sound levels are low and that the sound frequency usually lies below 100 kHz. The applications that are the medical and industrial generally make use of a wider range of ultrasound frequencies which is up to MHz and usually use much higher sound levels.

Ultrasonic Vibration

The wavelength or the vibrations that are beyond the audible limit of the ear of the humans are called ultrasonic or supersonic vibrations.

These vibrations have very possibilities that are interesting in the field of investigative dermatology. The purpose that is of my brief preliminary report is to call this subject to the attention of dermatologists which is as there are few reports that are on it in our literature.

The frequencies which are most commonly used in various biological, and medical, and commercial, and military applications have ranged from 100 to 1500 kilocycles.

The waves that are the ultrasonic waves generally differ from electromagnetic ones in that they do not traverse a vacuum. 

The term Ultrasonics is a name which is given to various specific topics in which the properties of ultrasound are exploited. The ultrasound is simply sound whose frequency is too high to be heard by the ear of human beings, that is to say the frequency is above c 20 kHz. 

Overview

Coulomb’s law deals with the force that acts between two distinct electric charges. According to the fundamental concept of the electric field,

Coulomb’s law is applied to static charges. An electric field is produced due to the motion of charged particles, and also when charges move relative to each other. Based on the experiments, it has been found that the electric field propagates through space at a finite speed (speed of light). The electric field concept is an essential aspect of the propagation of an electromagnetic wave through space, in a manner analogous to the propagation of light. By understanding the concept of the electric field, we can get to know how starlight travels vast distances through empty space.

Coulomb’s law is based on the idea of force acting at a distance. This force is caused by an electric field and acts upon a charge placed in this electric field. The electric field is the real concept and is denoted by the electric field lines. The electric field lines are useful in describing the motion of a charge in the electric field.

Definition of the electric field

The electric field [vec{E}] is a vector quantity. It exists in almost every point of space. The electric field describes the force which acts on a particle that is placed in the field. 

For an arbitrary charged particle having charge q, the electric field is given by

[vec{E} = frac{vec{F}}{q}]

The dimension of the electric field is Newton’s/coulomb or N/C.

Based on the electric field, the electric force is described as:

[vec{F} = q vec{E} ]

For a positive charge q, the direction of the electric field is in the same direction of the force vector.

We can calculate the value of the electric field by using Coulomb’s law. By substituting a test charge q in the numerator of Columbus law, and a charge qi, we can get the electric field as follows.

Coulomb’s Law:

[vec{F} = frac{1}{4pi epsilon _{0}}frac{qq_{i}}{r^{2}}widehat{r}_{i}].

Electric Field:

[vec{E} = frac{vec{F}}{q} frac{1}{4pi epsilon _{0}} frac{q_{i}}{r^{2}} hat{r_{i}}]

Where [widehat{r}_{i}] is the unit vector, which indicates the direction of the electric field between from the source charge to the target test charge i.e., from q to qi.

Unit of Electric Field

The SI unit of an electric field is volt/meter.

Explanation: Electric field intensity is the force that acts on a unit positive charge placed in that field. The electric potential is the amount of work that is required to bring a positive unit charge from infinity to the point of influence of the electric field. 

From this explanation, we can say that, when a charged particle moves in a region of the electric field, an electric potential is developed. Thus, the electric potential is the work done in moving a particle. We can calculate the electric potential by multiplying the electric field with a displacement vector. Electric potential is given by:

E ∗ r = v

Insights on electric field

The electric field is a modified electric force experienced by a unit positive test charge.

You can visualize the concept of the electric field in this way. Imagine a unit positive test charge placed at a point. Now bring a charge of higher magnitude near that test charge. The test charge will experience either a push or pull due to the influence of the electric field of the other charge.

The force that the test charge experiences at any point of the electric field, when divided by the magnitude of the test charge, is the electric field at that point. The direction in which the test charge experiences force is the direction of the electric field at that point. An electric field exists even if the test charge is removed from that point.

Surface tension is an interesting topic to study. It is defined as the attractive force that is found mostly in liquids which usually pulls molecules in the surface together. This results in the minimization of the area of the surface. In technical terms, the surface tension is the energy required to increase the surface area of a liquid by a unit of area. The surface tension is present due to the imbalance of attractive intermolecular forces or we say the cohesive forces that are between molecules. This phenomenon mostly occurs with water generally but it can happen with other liquids as well. Let us look at some surface tension units.

The Unit of Surface Tension

We find many of the examples of surface tension in nature and we have listed a few of them below in the article:

• There are small insects such as water striders walking on water because their weight is not that enough to penetrate the surface tension.

• A needle that is small when carefully placed over the surface of water can be made to float on water though the needle is several times denser than water. If the surface is agitated to break the tension ultimately, then the needle disturbs the surface tension and will sink quickly.

• The detergent and the soaps lower the surface tension of water so that it can more readily soak into solid and pores areas.

• The droplets of water that acquire their round shape due to surface tension. They are pulled spherical shape by the force that is cohesive of the surface layer

Surface tension is the tendency of surfaces of liquid to shrink generally into the minimum surface area possible. The phenomenon that is surface tension allows insects that are water striders to float and slide on a surface of water without becoming even partly submerged.

There are primarily two mechanisms that are in play. One is a force that is inward on the surface molecules which is causing the liquid to contract. There is a second method that is the tangential force parallel to the surface of the liquid. The net effect is the liquid that generally behaves as if its surface were covered with a stretched elastic membrane.

Unit of Surface Tension of Liquid

The force that is the cohesive one between liquid molecules is responsible for the phenomenon that is called as surface tension. The molecules which are at the surface of a glass of water do not have other water molecules on all sides of them. It is not really said to be true that a “skin” generally forms on the water surface. The force which is the cohesive one between the molecules in a liquid are shared with all neighboring molecules. Those which are on the surface have no neighboring molecules above and thus they exhibit a force which is the stronger attractive forces upon their nearest neighbors on and below the surface. Surface tension could be generally defined as the property of the surface of a liquid that allows it to resist an external force which is due to the cohesive nature of the water molecules.

The molecules of water want to cling to each other. However at  the surface there are fewer molecules of water to cling to since there is air above thus we say that there are no water molecules. This usually results in a bond that is stronger between those molecules that actually do come in contact with one another and a layer of strongly bonded water as well. This layer of the surface that is held together by surface tension) creates a barrier that is considerable between the atmosphere and the other water. In fact we can say that  other than mercury only water has the greatest surface tension of any liquid. 

Within a human body that is made up of a liquid there is a molecule that will not experience a net force because the forces by the neighboring molecules all of then get cancelled out . However for a molecule which is on the liquid’s surface, there will be a net inward force since there will be no attractive force acting from above. This inward force or the net force causes the molecules that are on the surface to contract and to resist being stretched or broken. Thus we can say that the surface is under tension which is probably where the name that is “surface tension” came from. 

Now due to the phenomenon of surface tension there are small objects that will “float” on the surface of a fluid, as long as the object cannot break through and the objects cannot separate the top layer of water molecules. When an object is on the surface of any of the fluids there is the surface under tension will behave like an elastic membrane.

A battery is a collection of chemical cells having a cathode and an anode, which creates the flow of electrons in a circuit. 

Batteries work as a mediator between electronic appliances and electric current supply. They are available in numerous shapes and sizes according to their type and use. 

Batteries are a compact source of energy. Energy storage is a major problem throughout the world. Batteries solve this problem by reducing the storage capacity very little and eliminating the need to carry fuel. Batteries are one of the most convenient ways to store power. 

All batteries that are invented to date are composed of three basic components: an anode (negative terminal), a cathode (positive terminal), and an electrolyte (which is usually a chemical substance that causes a reaction between anode and cathode). 

When the negative terminal and the positive terminal of a battery are connected in a circuit, a chemical reaction occurs between the electrolytes and the negative terminal. This reaction generates electrons that flow through the circuit and get deposited in the positive terminal i.e., the cathode. When the cathode or anode material is consumed, the reaction stops occurring, and the battery stops generating electricity. Here the battery is called ‘dead’. 

Types of Batteries

The type of batteries can be classified into two categories mainly:

1. Primary Battery

The type of battery that cannot be recharged again and which has the capacity to produce electricity immediately needed is known as Primary Battery. It is non-rechargeable and disposable by nature. Such batteries drain out and stop producing the current as soon as the energy of their supply gets exhausted. Zinc Carbon and Alkaline Batteries are the major types of Primary Batteries. On a major basis, Primary Batteries are of utmost useful for small appliances such as Flash Lights or radio as the size of the Primary Cell is comparatively small and standard in size. Interestingly, the energy that is consumed during the manufacturing of Primary Batteries is almost 50 times higher than its actual energy supply and that is why Primary Batteries are a significant cause of pollution resulting in unfriendly technology towards the environment. 

2. Secondary Battery:

The type of battery that can be recharged and reused again, is known as a Secondary Battery. Unlike Primary Batteries, Secondary Batteries are produced in different shapes and sizes and are comparatively costlier than Primary Batteries. But on the other hand, Secondary Batteries do not commit any harm to the environment as they are reusable and can be recycled too. The period of usage of Secondary Battery is much longer and efficient.  It can be recharged as many times as a person wants. The major use of Secondary Batteries is reported by the Automobile Industry, a variety of portable devices used by consumers and by different types of vehicles. For vehicles that operate on batteries, there are numerous power stations at regular intervals to recharge the battery of the vehicle in order to operate it.

Usual Lifetime of a Battery

The average lifetime of a battery depends on its type and size. Non-rechargeable batteries have comparatively a low lifespan as their cells exhaust quite early whereas rechargeable batteries have a long lifespan as they can be recharged again and again until their cells are operational in nature. A lot of factors affect the battery life stated as below:

• Self Discharge: Lack of supply of current leads to Self-discharge of batteries especially with disposable batteries. 

• Corrosion: Corrosion in the internal parts of the batteries is one of the major reasons for its short lifespan. Because of internal corrosion, the active parts of the batteries also become inactive. 

• Physical Components Changes: The life of electrical appliances depends a lot on their physical state. 

• Charge/Discharge Speed: With changing technology, there is equipment that helps in the fast charging of any device. Such equipment may increase the speed of charging but in return decreases the lifespan of a device. Thus, leading towards dead batteries. 

• Overcharging: Just like fast charging, overcharging of batteries, again and again, leads to its damage. They can be of no longer use if overcharged repeatedly.

• Memory Effect: Overuse of memory of a device also leads towards a shorter lifespan of batteries. Over storage of data fills the whole memory of the device and damages the internal memory of the device because of which the battery is also affected. 

• Environmental Effect: The temperature range of weather affects the battery life a lot. In case of extreme weather conditions, the battery level may fluctuate leading it to recharge again and again which results in battery failure. 

• Storage: An average life of a battery can be extended by keeping it at low temperatures. Though it depends on its different types and sizes too. 

What are the Uses of Battery? 

Here are some major uses of batteries in our day-to-day life. 

1. Around the House 

Batteries are used in various things that we use in our house. Batteries are used to power things like remote controls, torches, wall clocks, flashlights, hearing aids, weight scales, etc. 

Rechargeable batteries are also used in various devices like digital cameras, mobile phones, batteries of vehicles, video game devices, remote control cars, home maintenance tools, and many more. 

2. Medical Environments 

Hospitals, health centers, and other emergency services depend upon batteries to a great extent. Batteries are necessary to make devices like electrocardiograms, electrocardiographs, infusion pumps, glucose meters, and other testing kits function properly. 

Nickel-cadmium batteries and lithium-ion batteries are highly used in the medical industry because they can be recharged. 

3. Firefighting and Emergency Response 

Radio is the most important tool of an emergency responder. They serve as an easy way for communication in places where danger persists. These radios are powered by high-quality large batteries, which are capable of holding a huge amount of charge. 

Other devices like ECG monitors, metal detectors, and flashlights are powered by batteries. These devices are very necessary to save the lives of people. 

4. Military Use 

A utility tool and a set of batteries are the most important tool of armed personnel. 

The military environment may not witness the need for batteries at first, but they are used in many ways. Batteries are used to power radio communications, night vision devices, radar communications, optical equipment, and various other field devices, which make the work easier and safer. 

Batteries Used in Electric Vehicles 

The batteries used in electric vehicles are called the electric-vehicle battery (EVB) (or traction battery). This battery has its application in giving power to the electric motors of electric vehicles like battery electric vehicles (BEV) or hybrid electric vehicles (HEV). 

The batteries of electric vehicles are usually rechargeable (secondary) batteries, and typically lithium-ion batteries are used. These batteries are specifically designed for high output ampere-hour (or kilowatt-hour) capacity. 

Electric Vehicle Battery Types: 

Lead Acid Battery Uses 

Vehicles that need a constant source of uninterruptible energy use lead-acid batteries. Almost all vehicles in the world presently use this battery. 

For example, streetcars need lights that can function even when the engine is not running. The lights get the power from the batteries. Lead-acid batteries are also used in accessories like clocks and alarms. 

Industrial and automotive applications also use lead-acid batteries. The lead-acid batteries have gained much popularity, and are also highly used because of the following reason: 

1. Proven as regards performance. 

2. Recyclable. 

3. Economical to use. 

4. Easier to use. 

5. Safer compared to alternatives. 

6. They are capable of operating over a wide range of temperatures. G. These batteries don’t need any management service. 

Battery Used in Mobile Phones 

Batteries used in mobile phones are capable of holding a huge amount of energy, which makes the device keep running for hours. It is no doubt a miracle of chemical engineering. Let us try to know the working procedure of such high-performance batteries. 

Mobile phones use lithium-ion batteries (Li-ion), which consist of a pair of electrodes (a cathode and an anode) and an electrolyte. 

The electrodes are usually made up of materials like lithium, graphite, or even nano-wires, but they are based on the science of the functioning of lithium. Lithium is a highly reactive metal, and hence it tends to react with other materials. 

State the Unique Difference between a Cell and a Battery 

Battery: The function of a battery and a cell is similar, but a battery contains several cells arranged in either series or parallel to produce a voltage of desired levels. A power bank is the best example of a battery; it is used to charge mobile phones. 

Cell: A cell is a source of energy that generates only DC voltage and current of small magnitude. For example, the cells used in remote control or wristwatches can generate voltage within the 1 .5 – 3 V range.

Are Batteries Harmful in Any Way?

In the world, everything has its pros and cons, so do batteries. Batteries are undoubtedly used in every way possible. Whether it is in our daily life or professional life. Even children’s toys are battery operated.

In such cases where it is used in such a high amount, there are adverse effects of it too. It can affect human health as well as the environment. As responsible individuals, we can make or take care of it, maybe not for everyone but ourselves and the people residing with us. 

Everyone should be aware of things that can lead to negative effects from the use of the battery. Some things that should be taken care of are mentioned below.

• Not every battery but some or most batteries are made up of metals and chemicals that can be harmful in their particular manner. Even though great care is taken while making batteries, one should be always careful. 

• Metal like lead is considered a toxic metal. If we get exposed to lead many negative effects can take place in the human body. Where it is different for infants and pregnant women from an adult.

• In adults, it can lead to memory loss whereas it can affect more adversely on infants and pregnant woman’s fetuses.

• Most small batteries or button batteries are suggested to keep away from kids, as there are so many active cases going on only for the children who swallow batteries. 

• Not only the human body but the environment also gets affected by batteries if they are not disposed of properly. Many cases are registered from the areas or landfills where the batteries are disposed of. 

• Normal batteries can be disposed of along with the trash but avoid throwing batteries containing harmful chemicals and metals in them. 

• Associations are forming a dedicated team of people only working towards battery disposals so that hazards created from battery disposal can be reduced as much as possible.

• Every individual must contain in-depth knowledge about things that are hazardous to living beings and the environment, where battery disposal is no less than a topic to not consider.

• Overall batteries are not harmful if you use them properly.

 

Are Batteries Replaceable in Near Future?

When we say future, we always think about innovations. Things we cannot even think of or imagine about. But in the past few decades, we have seen innovations, upgrades, and new ways of using things. Whether it is from cabled telephone to wireless cell phones, or letters to texts, or mud pots to refrigerator. 

With time everything is either updated or replaced. Like can you see anyone sending letters through a pigeon or horseman? No right. But when we talk about the replacement of batteries, it feels impossible and possible at the same time.   

It is hardly impossible to think about something, which we use in our daily life operating on a battery. Many new materials are used to produce a new type of battery.

Maybe the use of metals and chemicals which are used currently can be replaced, but replacing the battery itself seems weird and something we are not used to seeing. 

Thus there is no guarantee for the future, so hoping for the best and making the best out of it for the environment should be considered.

Though there are interesting facts that state the statistical estimation of around 30% growth in the demand for batteries in the near future by  2030. Day by day the demand for electrical vehicles is incre
asing which leads to a rise in demands for more batteries and power stations. The use of Second Batteries is reported comparatively high against Primary Batteries. On average, the lifespan of batteries in electric vehicles is 5-8 years after which they can be recycled and reused again. Such an estimation may probably result in a reduction of overall cost and in the remarkable growth of demand for batteries.

When current is transferred from one circuit to another without any physical contact between the circuits, we use a practical transformer. It also does not allow changing the phase and the frequency. Depending on the type, there are various uses of a transformer. The transfer of electricity from one circuit to another through the electromagnetic induction process is known as a practical transformer. It is used to increase and decrease the voltage in the circuit. The increase in voltage is called “step up” and a decrease in voltage is called the “step down” method. A transformer that increases the voltage between primary and secondary winding is called a step-up transformer, and that decreased voltage is called a step-down transformer.

Transformer Parts and Construction

In a transformer, various parts are used for operations, such as the core, windings, brushes, vents, and many more. These individual parts boost up and help to work the transformer overall. To quote simply, in a transformer, there are two coins that are wounded on the same iron core. The material of the core is magnetic and is usually laminated. The coils are bounded and electrically insulated, but due to the presence of iron core, they get magnetically induced. The primary coil P is where the voltage is applied and the secondary coil S is where the output is drawn out. And this entire setup is kept in an environment suitable for better insulation and cooling purposes.

The transformer has three main parts:

• Transformer Primary Winding

• Transformer Magnetic Core.

• Transformer Secondary Winding.

Transformer Primary Winding: When it is connected to an electrical pole, it produces electric flux.

Transformer Magnetic Core: A close circuit will be formed when the reductant path will be linked with the secondary winding. The magnetic flux produced by the primary winding that will flow through this reductant path creates a magnetic circuit.

Transformer Secondary Winding: The flux passes through the core that is linked with the secondary winding. The flux is produced by the primary winding. On the core, the wind is done with the same flux and gives the output of the transformer.

Application and Uses of a Transformer

Power Transformers: 

The transformers which are used for high voltage power transfer applications (more than 33 Kilovolt) are called Power Transformers. They are usually very big. They can occupy a wide area of space.

Distribution Transformers: 

The transformers which are used to distribute the generated power to distant locations are called distribution transformers. At a low voltage, it is used for distributing electricity that is less than 33 Kilovolt in industry. It also distributes 220-440 V for household purposes.

Measurement Transformers: 

The transformer which helps in measuring voltage, current, power, etc. is called a Measurement Transformer.

Transformers are classified according to the place of use, and are as follows:

Indoor Transformers: 

The transformer that is covered with roofs and shelters, just like the industry types, is called an indoor transformer.

Outdoor Transformers: 

The transformer that is mainly kept outside and is used as distribution type transformers is called an outdoor transformer.

Types of Transformers

There are types of transformers based on different parameters, such as the construction or usage for the input requirements. 

1. Transformer based on the Phase Requirements:

Depending upon the phase, there are two types of transformers: Single-phase transformer and three-phase transformer.

2. Transformers based on the Core Design:

Based on the design of the core, there are three types of transformers: shell-type transformer, core type transformer, and berry type transformer.

3. Transformers based on the Core Type:

Based on the type of the core, there are two types of transformers: air-core transformer and ferromagnetic or iron core transformer. 

Three-phase Transformer over Single-phase Transformer

Transformers are used to transfer electrical energy from one circuit to another. The mechanism behind the working of transformers is electromagnetic induction.  However, depending upon the phase, there are two types of transformers: single-phase transformer and three-phase transformer.

Advantages of three-phase transformer over single-phase transformer are:

• Comparatively lesser cost

• Lighter in weight

• Delivers more power

• Is highly efficient

• List space is required

• Easy installation

• Less maintenance required 

• Transportation is comparatively easy

• Easy to assemble and repair

• A single-phase power can be derived from a three-phase power, whereas the reverse cannot be done. 

There are various advantages of using a three-phase transformer. But there are also some limitations that might be caused by using a 3 phase transformer over a single-phase transformer, which are as follows:

• The costs are higher as construction is more.

• Repair and maintenance take up a large amount of money.

• If an emergency occurs at any particular site, then the entire area gets shut down.

• If the system is shut down, then immediate maintenance cannot be done.

• If there is any error, then the entire unit needs to be replaced, but in a single-phase transformer, only the particular ones can be replaced.

Vaporization is the stage of an element or compound turning to a gaseous state from the liquid state. There are two types of vaporization and they are evaporation and boiling.

Evaporation is the surface process wherein sprinkles of liquid spread on the ground turn to steam when the surface is hot. However, boiling is a bulk phenomenon, meaning, this process occurs when the vessel filled with water is kept on high flame and the liquid turns to steam.

In this article, we will discuss how vaporization occurs, types of vaporization, in detail.

Vaporization

One thing to note is that heat is required to convert solid or liquid into a gaseous (steam) state.

When a system captures hear from its surroundings, there is a temperature rise. So, when there is a temperature rise, the atoms or molecules of a liquid or solid that are held together by cohesive forces, turn to adhesive forces, which in turn,  separate the atoms or molecules to form the vapor; therefore, the heat of vaporization is a direct measure of these cohesive forces.

It means more is the cohesive force between molecules, the more is heat required to vaporize the solid or liquified elements.

Now, let’s understand the types of vaporization:

Types of Vaporization

There are three types of vaporization, and these are as follows:

• Evaporation

• Boiling

• Sublimation

Evaporation

It is a phase transition from the liquid to the vapor phase, i.e., a state of substance/material below the critical temperature occurs. 

Evaporation occurs at temperatures lower than the boiling temperature at a given pressure, it always occurs on the surface. That means the water suddenly escapes into the atmosphere (no formation of bubbles or something).

Drying your clothes on the roof is an example of evaporation.

Point to Note:

Evaporation occurs only when the partial/incomplete pressure of vapor of a substance/material is lower than the equilibrium vapor pressure. 

Another example, due to continuously decreasing pressures, vapor pumped out of a solution eventually leaves behind a cryogenic (cancer-causing) liquid at temperatures below the boiling temperature at a given pressure. 

Boiling

Boiling is similar to evaporation. It is also known as the phase transition from the liquid to the gas phase, but boiling is the formation of vapor as bubbles of high-temperature water below the surface of the liquid just like we keep the water jar on a high flame, it turns to bubbles and then the steam escapes into the atmosphere. 

Point to Note:

Boiling occurs only when the equilibrium vapor pressure of the substance is greater than or equal to the environmental/atmospheric pressure. 

Hence, the temperature at which boiling occurs is the boiling temperature or boiling point. The boiling point varies with the pressure of the environment or the atmospheric pressure.

Sublimation

We all know that firstly ice converts to liquid and then this liquid turns into steam; however, there is a process that directly converts solid into gaseous form without turning to the liquid phase. So, the direct transition of solid into the gaseous state is sublimation.

Uses of Vaporization

The term vaporization was being used in colloquia/hyperbolic manner to allude to the physical destruction of an object/element that is exposed to intense heat or explosive force, where the object of large mass is split into small pieces rather than converting into gaseous form. 

The example includes the usage of the “vaporization” in 1952 the Ivy Mike thermonuclear test that was performed in the uninhabited Marshall Island of Elugelab.

Vaporization or Ablation

Vaporization occurs when a laser heats the material above or equivalent to its boiling point. The high-power densities generated by short-pulsed lasers let the vaporization occur with minimum thermal damage to the surrounding material. This, in turn, allows fine features to be formed without the production of any notable heat-affected zone or recast layer.

Point to Note:

In the process of laser drilling, the term ablation is usually used to indicate a vaporization-dominated process. Though, the term is not well-defined; however, this term applies to processes in which there is also significant melting.

Saturated Vapour

When evaporation occurs in a closed container, it proceeds until all the molecules inside the liquid escape. At this juncture, a vapor is said to be saturated. The pressure of the saturated vapor is expressed in mmHg; this pressure is also called the saturated vapor pressure.

Since the molecular pressure and the kinetic energy of each molecule inside the container is high because of the high temperature; therefore, more molecules escape the surface, and the saturated vapor pressure also increases.

The below diagram shows how the saturation occurs:

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Vapor Lock

A Vapor lock is a partial/complete interruption/disruption of the fuel flow in an internal-combustion engine that is caused by the formation of vapor or bubbles of gas in the fuel-feeding system. 

Vapor lock disrupts the operation of the fuel pump, leading to the loss of feed pressure to the fuel injection system, resulting in transient loss of power or complete stalling/stoppage.