Category: Physics Notes PPT

A particle accelerator is a machine that propels charged particles to very high speed and energies by using electromagnetic fields. And contains them in well-defined beams. In the research of particle Physics, large accelerators are used. Large hadron collider is the largest operator currently operating in basic research work, it is near Geneva, Switzerland. It can accelerate two beams of protons to an energy of 6.5 TeV and it makes them collide in such a manner that it creates center-of-mass energy of 13 TeV. Some other powerful accelerators are listed here: SuperKEKB in Japan, Tevatron at Fermilab. 

For the study of considered matter in physics, synchrotron light source accelerators are used. There are a wide variety of applications in which they are used that are particle therapy for oncological purposes, for medical diagnosis- production of radioisotope, measurements of the rare isotope such as radiocarbon- accelerator mass spectrometer. In operation around the world currently, there are more than 30,000 accelerators.

Electrostatic and electrodynamic or electromagnetic are two basic classes of accelerators. Electrostatic accelerators are used in accelerating particles in static electric fields. On the other hand, the electrodynamic or electromagnetic accelerators use charging electromagnetic fields.

Types of Particle Accelerator

Particle accelerators are split into two types, oscillating field accelerators, and electrostatic accelerators. Electrostatic accelerators e.g. Cocacroft-Walton and Van de Graaff accelerators make use of electrostatic fields. Electrostatic fields do not change with time. The only disadvantage of using an electrostatic field is it needs a generation of large amounts of electric fields to accelerate particles. This disadvantage gave birth to another type of accelerator- the oscillating field accelerator. This type of oscillator needs an electric field to work that periodically changes with time. The use of an oscillating electric field allows high energy physicians to accelerate particles to high energies leading to many key discoveries.

The Van-de-Graaff and Cocacroft-Walton Accelerators:

These are two types of particle accelerators developed in the 1930s, the Cocacroft-Walton accelerator wad developed by John Cocacroft and Emest Walton at Cambridge, England and the Van-de-Graaff was developed by Robert van-de-Graaff while working as a postdoctoral researcher assistant in the U.S.A. Cocacroft and walton generated a voltage of 800,000 volts. The proton was then accelerated along an 8-foot vacuum tube, where they collided with the lithium target achieving first nuclear disintegration.

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Uses of Particle Accelerator

Physicists like playing and that ok if the toys they like were not useless. This is what, when people hear of the particle accelerators. Scientists are aware of hard work and feelings to raise awareness about the use of particle accelerators in daily life. From industry to energy supply and from health to security there are many fields beyond pure research in which accelerator related technology impacts everyone’s life in a positive manner. Particle accelerators are designed in such a manner so that they can propel particles through electromagnetic fields, and pack them into a beam. They have been built for science the first decade and can be circular, linear, or even small enough to hold on hands or at times too big or giant. There are thousands of particle accelerators all over the world, which allows scientists to learn about the building block of the matter.

The outcome of a particle accelerator is not just till that, there are many positive applications of particle accelerators. In medicine, the particles which are accelerated are used for treating cancer and killing its cells. Accelerators are also used in scanning inside containers and help in identifying dangerous weapons. They are used in many more things like in treating wastewaters, the creation of new materials, sterilization of medical equipment, and pollution monitoring.

Applications of Particle Accelerator

There are few researched applications of a particle accelerator in practical physics: The development of particle physics has directly been determined by the progress seen in building accelerators of increasing energies. Examples are the discovery of the antiproton, in the mid-fifties. The discovery of two neutrons in the early sixties. In about forty years the colliders and accelerators have allowed us to gain three orders of magnitude. HERA- a new facility for probing using electron hadron has been commissioned in Hamsbug. 

Particle Accelerators Use in Nuclear Physics:

They are the essential tools through which physics has discovered the nucleus determined it’s structure and individual nuclei. It depends upon the property of the interest that one is using electrons, protons, and heavy electric beams. The increase in intensity and energy is also opening new opportunities. Early nuclear physics was devoted to studying the structures of individual nuclei, their associated states, and excited states. 

Cosmology and Astrophysics: these are now becoming more complimentary for telescopes, our universe originated in a hot big bang, the increasing energy of colliders and accelerators, with decreasing temperature allows the physicists to study the process closely about the origin of the universe. 

AC phasor representation is an extremely important part of physics; it is taught in chapter 7 alternating current in class 12 physics, NCERT books that follow the CBSE curriculum. There are two types of currents that are studied in depth in class 12 physics that are alternating-current AC and direct current DC. This article mainly talks about alternating current AC. 

The concept of AC phasor representation can only be cleared after studying direct current DC.  DC current is a direct current that doesn’t change direction with time. However, voltages and currents that change with time are common. It is common in the sense that it is used in our homes and offices as the electric mains supply is a voltage which varies like a sign function with time. Such voltages are called alternating voltage or AC voltage and the current which is generated by it in a circuit is called alternating current or AC current. Nowadays the most common source of distributing electricity in homes and offices is an AC voltage. This is mainly because electrical energy which is sold by power companies is distributed as alternating current. AC voltage is extremely efficient in the sense that it can easily and efficiently be converted from one voltage to the other with the help of transformers. Another reason for its efficiency is that it can be helpful in distributing electricity over long distances.

A phasor representation is represented as a complex number that is functional in a sinusoidal manner. The time-invariant parameters are amplitude (A), initial phase (θ), and angular velocity (ω). This representation is based upon the concept known as analytic representation. A constant which is postulated by covering the frequency and dependence of time is known as phasor and complex amplitude. The term ‘phaser’ is eliminated from the diagrammatic calculations. It is equivalent to the vectors, which are possible for phasers also. The inventor of the phasor transform was Charles Proteus Steinmetz. He was working for General Electric earlier in the 19th century.

Phasor Representation AC

Electrical circuits consist of a resistor, which is linked with an AC source. An inductor is also connected with this AC source along with a capacitor or the joint of any two or all of the enlisted components linked with an AC source. In the case of a resistor, we know that the current is present in phase with the source of voltage. When it comes to the case of a capacitor, the current either increases or decreases the source of voltage to a certain amount. We need to use the concept of phasors to co-relate the voltage and the current. Phasor representation shows the perfect inter-relationship between the current and the voltage in a diagrammatic form.

Phasor Representation of Alternating Quantities

Before going to this topic, assume that the alternating voltages and currents obey the sine law. The generators are constructed to generate EMFs, which are generally in sine waveform. The assumption mentioned above implies the easiest form of calculation. Alternative quantities are given in the waveform. These equations imply spontaneous values are quite inconvenient. It is an advantage to elaborate on a sinusoidal quantity (generally voltage or current) for the solution of AC problems. It is represented by a line that is rotating in the counterclockwise direction, having a definite length with the same angular velocity. It is just like the sinusoidal quantity. This kind of rotating line is called the phasor.

Let’s consider the OA line (also called phasor) indicating the maximum scale value. It is the maximum value of an alternating quantity which can be termed emf i.e. OA = Emax. It is rotating counterclockwise with an angular velocity ω (rad/sec) about the point OF. It is shown in the figure above. At the outside end of the phasor, an arrow mark is drawn, at least to pinpoint which end is considered to move and slightly to mention the accurate length of the phasor when more than one phasors appear to synchronize. In the figure; OA has made a rotation with an angular velocity θ, which is equal to ωt when the emf was passing at zero magnitudes from a certain occupied position.OB = OA sin θ, OB is represented as the projection of OA on the Y-axis.We know, OB= OA sin θ = Emaxsin ωt = e. This is the value of the emf at that position.

This proves that the projection of OA which acts on the vertical axis acts in the place of the instantaneous magnitude of EMF. It has been observed that the phasor OA rotating in the counterclockwise direction will express a sinusoidal quantity (generally current and voltage). If the length of OA is equal to the maximum value obtained from the sinusoidal p current or voltage to a relevant scale. OA is in a horizontal plane at the current stage, and the alternating quantity (which is voltage or current) is zero and increasing. The angular velocity of OA is in such a state that it accomplishes one revolution at the same time. The time is the same for completing one cycle, which is taken by alternating quantities.

Phasor Representation of AC Quantities

It is a vector that is passed down to state a sinusoidal function. Phasor rotates at an angular velocity ω about the origin. The values which are sinusoidally altering can be represented by the vertical component of phasors for a given problem, like v and i. In this circumstance, the highest value of the voltage and the current is represented as the magnitude of the phasors. From the figure shown below, we can notice the relationship between the sinusoidal representation and a phasor concerning time. The value of the quantity is represented as the projection of the phasor on the vertical axis. For illustration, the projection of the phasor on the vertical axis is given by Vm sin t and i(m)sin t respectively in the case of a current or a vector phasor. It concludes the magnitude of the current or the voltage at that position.

It is simple to identify that one of the two quantities is in the equal phase with the help of the phasor diagram. For illustration, the phasors for the voltage and current are in the exact direction for all occurrences for a given circuit. The phase angle will be zero in between the voltage and the current.

Representation of AC and Voltage by Phasor diagram 

It is sometimes quite difficult to represent mathematically, to visualize the angular or phasor difference among sinusoidal waveforms. To overcome these problems, we need to represent the sinusoids graphically within the phasor-domain form with the help of the phasor diagram.

Plane Mirrors can be found very easily in our daily life. Though an average person is not familiar with this technical term, they can easily relate that to the normal mirrors which are polished on one side with mercury so that they can reflect light falling on them. A Plane Mirror can be easily defined as a mirror that is flat on the surface and is without any inward or outward curve. They can easily reflect light in various directions, undergoing certain phenomena namely reflection, refraction, or absorption. In the Plane Mirrors, we require at least two rays through which the image of the object can be formed by observing the endpoints of the 2 light rays taken. The Plane Mirror can be polished with various materials that can be used for various purposes but all the mirrors function the same way regardless of their constructing material. According to their reflection of light, they can be classified into 3 types: concave, convex, and Plane Mirror. In the case of a Plane Mirror, the angle at which the ray is reflected is equal to the angle at which the ray of light is incident, regardless of whether the image is real or virtual, where the angle of incidence is the angle formed at an imaginary surface which is normal to the mirror (which is perpendicular to the surface) at the point of incidence. While the angle of reflection can be defined as the angle formed at the point of contact of the reflected ray and the surface normal of the Plane Mirror.

 

Image Formation on Plane Mirrors

To see any image in the mirror a person should be in the line of sight of the mirror, as when the person is in the line of sight of the mirror then the reflected ray reaches that person’s eye through which anyone can see the image of the object if they are in the line of sight of the mirror, this is because light has the property of moving in a straight line. The important phenomenon of the Plane Mirror is that the reflections of the objects form the virtual image with the same magnification, size, and distance as the object are. The image of the object depends on the geometrical line through which a person sees in the mirror, though all the lines of sight will provide the image of the object, as long as the person‘s eye is in line with the mirror. The image produced is on the opposite side of the mirror with the distance of the image from the surface is equal to the distance of the object from the surface, that is the reason why a person can see what’s exactly behind him.

There can be 2 types of image formed by mirrors, which are:

1. Real Image

2. Virtual Image

The main difference between the real and virtual image is that in a real image the rays of light pass through the mirror while in a virtual image the rays of light strike the surface of the mirror and bounce back to the eye of the user.

Real Image

The real images of the objects are generally formed by the curved mirrors as in the curved mirrors the rays of light get reflected and pass through the mirror to form the real image. The real images formed by the curved mirrors are always inverted. Some examples of a real image are the image formed on the retina of the eye or the image formed on the film of the camera.

Virtual Image

The virtual image of the objects is generally formed by the Plane Mirrors as the Plane Mirrors are polished on one side so the reflection of the object strikes the mirror and gets reflected towards the direction of the observer’s eye. So due to this, the observer sees the image at the same distance as the object is from the mirror. The image formed by the Plane Mirror has the same magnification, size, and distance of the object. These virtual images of Plane Mirrors are not formed on the screen like that of a real image. Some examples of Virtual images are the image formed by a magnifying glass when used to look at small objects.

 

Laws of Reflection:

There are generally two laws of reflection which can be stated as follows:

1. The angle of incidence (i) is always equal to the angle of reflection (r).

2. The reflected ray, the normal at the point of incidence, and the incident ray lie on the same plane.

 

Properties of Reflection in Plane Mirrors:

The magnification of the Plane Mirror is always 1, which is calculated by combining these properties of reflection. 3 things can happen when the light ray falls on the surface of the mirror, which is as follows:

1. A fraction ‘r’ can be reflected.

2. A fraction ‘a’ can be absorbed.

3. A fraction ‘t’ can be transmitted.

For any given surface of a Plane Mirror, these above terms should add up to form 1.

I.e. r + a + t = 1.

 

Characteristics of Plane Mirrors:

1. Images formed by the Plane Mirrors are always visual.

2. Images formed by the Plane Mirrors are erect/ upright and are of the same size as the object.

3. The image formed by the Plane Mirror is of the same size as the object.

4. An image formed by the Plane Mirror is of the same magnification as that of the object.

5. One of the main characteristics of the Plane Mirror is that the image formed by the Plane Mirror is inverted, which means if you raise your left hand then the image of the Plane Mirror will show the right hand going upwards.

 

Types of Reflection:

There are two types of reflection in Plane Mirrors, which are:

1. Specular/ Regular Reflection

2. Diffused/ Irregular Reflection

Specular / Regular Reflection:

The Specular / Regular reflection, as the name says, provides the perfect image of the object without any distortion. We can simply say when the light strikes the smooth surfaces the ray of light gets reflected in the same direction, as each incident ray is reflected along the reflected ray having the same angle as that of the incident ray. E.g. The mountains are covered with lakes. The image of the mountains shown in the lake is perfect as the lake is a smooth surface.

Diffused / Irregular Reflection:

The Diffused / Irregular reflection is the type of reflection in which the light after striking the rough surface gets reflected in all directions, it includes any light which we can see through our eyes. In this type of reflection, the incident ray reflected along the reflected ray does not have the same angle as that of the incident ray. E.g. When the light hits a bird which is a rough surface, the reflected light scatters in all directions, when it reaches our eye and hits the retina it gets processed in the brain from an electrical signal to form an image of a bird.

 

Uses of Plane Mirrors:

1. Seeing around corners

2. Dental mirrors

3. Periscope

4. Flat Telescope

5. Illuminating Egyptian tombs

6. Overhead projectors

7. Kaleidoscope

8. Optical lever

Energy is the capacity to do work in physics. It exists in potential, kinetic, thermal, electrical, chemical, nuclear, or other forms. You can connect with the best online learning platform  , to get a complete understanding of the topics related to the chapter Energy and download FREE PDF Potential and Kinetic Energy – Different Types, Formula, Solved Numericals, etc.

Potential Energy

Potential Energy definition states that “It is the energy stored that depends on the relative location of the different parts of the system”. In systems with parts that exert forces on each other of a magnitude depending on the configuration or relative position of the parts, Potential Energy arises.

When compressed or extended, spring has more Potential Energy. A steel ball after dropping to Earth has less Potential Energy compared to when lifted above the ground. Potential Energy is capable of doing more work in an elevated role. Potential Energy is a system property and not of an individual body or particle; for example, the system consisting of Earth and the raised ball has more Potential Energy as the two are separated further.

The Potential Energy of an object depends only on its original and final configurations. It is independent of the direction traveled by the objects. If the initial position of the ball is ground level and the final position is 10 m above the ground, in this case of the steel ball and the Earth, the Potential Energy is the same, regardless of how or by what route the ball was lifted. The value of Potential Energy is arbitrary and is proportional to the reference point selection. In the above example, if the initial location was the bottom of a 10 m deep pit, the device would have twice as much Potential Energy.

Different Types of Potential Energy

• Electrical Potential Energy is the energy stored between the plates of a charged capacitor.

• Chemical energy, the ability of a substance to work or to produce heat from a change in structure, may be considered as Potential Energy arising from the reciprocal forces between its molecules and atoms.

• Nuclear energy is a form of Potential Energy as well.
  

Gravitational Potential Energy

The Potential Energy that a massive object has another massive object due to gravity is Gravitational Potential Energy. When the objects fall towards each other, it is the Potential Energy associated with the gravitational field that is released.

By multiplying the weight of an object by its distance above the reference point, Gravitational Potential Energy near the Earth’s surface can be measured.

Inbound structures, such as atoms, where electrons are retained by the electrical force of attraction to nuclei, the zero reference for Potential Energy is such that the distance from the nucleus is not measurable by the electrical force. Bound electrons have negative Potential Energy in this case, and those so far away have zero Potential Energy.

Potential Energy Formula

The Gravitational Potential Energy formula relies on the force that acts on the two objects. The formula for the Gravitational Potential Energy is,

P.E. = m*g*h 

Where m is the mass in kilograms,

g is the acceleration due to gravity(9.8 m/s2 at the earth’s surface) and 

h is the height in meters.

The SI unit of measurement of Potential Energy is kg. m2/s2 or Joule(J).

Some examples of Potential Energy include:

• Compressed or extended spring.

• A ball raised to some height.

• Stored water in the Dam.

• A car parked on the hilltop.

• An arrow about to be shot.
  

Kinetic Energy

Kinetic Energy is the form of energy in which the object or a particle is said to be in motion. If the work that transfers energy is done on an object by applying a net force, the object speeds up and thus gains Kinetic Energy.

Kinetic Energy is a property of a moving object or particle which depends not only on its movement but also on its mass. Translation, rotation around an axis, vibration, or some combination of motions can be the form of Kinetic Energy.

Kinetic Energy Formula

Kinetic Energy is directly proportional to the object’s mass and its velocity square, which is  K.E. = 1/2*m*v²

Where m is the mass in kilograms,

v is the velocity in m/s.

The SI unit of measurement of Kinetic Energy is the same as Potential Energy which is kg. m2/s2 or Joule(J).

The Relation Between Potential Energy and Kinetic Energy

Kinetic Energy is nothing but a form of converted Potential Energy. Potential Energy can be transformed into the energy of motion such as Kinetic Energy and in turn into other forms, such as electric energy. Thus, through turbines that transform electric generators, water behind a dam flows to lower levels, generating electric energy plus some unusable heat energy resulting from turbulence and friction.

Potential Energy and Kinetic Energy are a form of mechanical energy so that the total energy in gravitational systems can be calculated as a constant.

Some examples of Kinetic Energy include:

Solved Numerical on Potential and Kinetic Energy

1. In a running race competition, a student who is weighing 40 Kg is running at 4m/s. Calculate the Kinetic Energy of the student.

Ans: It is given that the weight/mass of the student, m = 40 Kg.

The velocity of a student, v = 4m/s.

Kinetic Energy is given by the formula, K.E.=1/2*m*v²

Substituting the values we get, K.E.= 1/2 * 40 * 4*4 = 320 kg. m2/s2.

Therefore the Kinetic Energy of the student is 320 kg. m2/s2.

2. A water tank of mass 50 Kg is stored at a height of 10m. Calculate the Potential Energy of the tank. Consider the value of acceleration due to gravity(g) = 10 m/s2.

Ans: Given the mass of the tank, m = 50 Kg.

Height = 10m and g = 10 m/s2.

Potential Energy formula is given as P.E. = m*g*h.

Substituting the values we get P.E. = 50*10*10= 5000 kg. m2/s2.

Therefore the Potential Energy of the tank is 5000 kg. m2/s2.

We know that the flow of electric current can generate a magnetic field around it in a plane perpendicular to the direction of the flow of electric current. The electromagnets are the coil that is wrapped around the iron bar or rod. The electromagnets are the magnets that are created when the electric current is passed through it. These electromagnets have immense applications in everyday life and every industry. The electromagnets work on the principle of electromagnetic induction. 

Therefore, an electromagnet can be defined as a magnet that works with the help of electricity. But the electromagnets are not like permanent magnets, the strength of the electromagnets can be altered by repeated variation in the amount of electric current that flows through them. If the flow of electric current is disconnected, the property of magnetism will be lost, thus the effect of the electromagnets depends on the amount of electricity. In this article, we will discuss the principal applications of the electromagnet, electromagnet use, electromagnet application, etc…

Uses of Electromagnet:

What is an Electromagnet and How Does it Work?

Before we start with the uses of electromagnets or the principal applications of electromagnets let us have a look at the theory and the principle of electromagnets.  For a long time, people have entrusted the fact that both electricity and magnetism are two different things and can not be studied simultaneously. In the early 18th century many scientists and physicists started to investigate these phenomena and suspected that they were related to each other. As the advancements took place scientists gave the equations that related electricity and magnetism with a good agreement. 

While scientists were working on the relation between electricity and magnetism, a Danish scientist Hans Christian Ørsted is the first one who discovered the relation between electricity and magnetism, in 1820 he proved that electric currents create magnetic fields. Later, in the year 1824, British scientist William Sturgeon invented the electromagnets without violating the laws of physics.

So, now the question that arose was how does an electromagnet work? The electromagnets work on the principle of electromagnetic induction and the effect of an electric current producing a magnetic field. The magnetic field generated by an electric current appears to be forming circles around the electric current known as the magnetic field lines.

So the construction of electromagnets is very simple, it requires a coil and conducting bar, usually, we use iron as the support. If an electric coil or any wire carrying an electric current is formed into a series of loops (concentric loops), the concentration of the magnetic field can be varied within the loops, by altering it. The strength of the magnetic field generated can be strengthened by wrapping the wire up and around the core of the magnet. The atoms of magnetic materials behave like magnets, for example, iron, nickel, and cobalt, which appear to be behaving like tiny magnets. 

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When we vary the concentration of the magnetic field, suppose we increased the concentration of the magnetic field, the amount of electric current that is flowing around the core increases and as a result of the number of aligned atoms increases which further results in stronger a magnetic field Sooner or later, all of the atoms that are supposed to be aligned will be aligned. At this particular point when the atoms are aligned with each other, the magnet is said to be saturated, and it experiences an increasing electric current flowing around the core. This no longer affects the magnetization of the core itself.

The electromagnets are widely used in most industries, starting from the basic electrical industries to the medical field the electromagnets are used most frequently. Electromagnets are used for various purposes even in our day to day lives, which makes our living easy. For example, electromagnets are used in electric fans, cookers, etc. without these appliances, our lives would have been miserable. Let us have a look at few familiar uses of electromagnets and where are electromagnets used as listed below:

• The electromagnets are used in the manufacture of electric bells.

• Electromagnets are used in Headphones and loudspeakers.

• The electromagnets are an important part of the data storage devices such as VCRs, tape recorders, hard discs, etc…

• These days, the use of electromagnetism has been a gift in many ways. Especially, for domestic purposes, for example, the Induction cooker which we use in our day to day life works on the principle of electromagnetic induction and uses electromagnets as a crucial part.

• Just like the electric bells, buzzers, these days even magnetic locks are available in the market that uses electromagnets.

• The applications of electromagnets are wide, the electromagnets are even used in the medical field, for the MRI machines used to diagnose the patient.

• When we are discussing the principal applications of electromagnets, we should not forget the Particle accelerators, even the particle accelerators use the electromagnets as their important part.

• Even in the construction of the mass spectrometers, electromagnets are used.

These are the basic and essential uses of electromagnets that we come across in our day to day lives.

Application of Electromagnet:

We know that there are four fundamental forces available in nature and we study them as the basic forces in physics, and one of the four fundamental forces is the electromagnetic force. As the name itself suggests electromagnetic force is a combination of two forces i.e., the combination of electric forces, and magnetic forces. Let us discuss how these forces can contribute to the working of electromagnets.

The electric force and the magnetic force are very different from each other, but when they combine, as a result of a combination of electromagnetic forces. The electric force and the magnetic forces complement each other in every possible way and are used in many days to day applications.

The elementary particles protons and electrons are the main reason for these two forces to act together. When the electrons and protons are stationary (i.e., at rest), they produce electric forces, which can be either attractive or repulsive in nature depending upon the nature of the charged particles. But when electrons and protons are dynamic in nature (i.e., under motion), they produce magnetic forces which can be either a force of attraction or repulsion between the charged particles that are formed as a result of the motion of the charged Particles.

Now, let us have a look at the application of electromagnets. As we already know electromagnets are having huge applications in almost every field. But they play an important role in several fields of sciences in constructing a few types of equipment. A few important application of electromagnet and how are electromagnets used in the real world are as mentioned below:

The Electromagnets are More Often Used for Domestic Purposes for Many Home Appliances:< /span>

• Most of the electric home appliances used for domestic purposes use electromagnetism as the basic working principle. 

• A few electromagnets utilized in the household incorporate an electric fan, electric doorbell, induction cooker, magnetic locks, etc… 

• In an electric fan (either it may be a standing fan or a ceiling fan), the principle of electromagnetic induction keeps the motor rotating without any break, as a result of the rotation of the motor the blades or the wings of the fan keeps rotating without any obstruction. Similarly, even in an electric doorbell when the button is pressed, as a result of the electromagnetic forces, the coil gets energized and the bell rings.

The Electromagnets are Even Used in the Medical Field:

• The uses of electromagnets are also seen in the medical field. MRI scan which is short for Magnetic Resonance Imaging is a device that uses electromagnets. 

• The device can scan all the tiny details in the human body with the help of electromagnetism.

The Electromagnets are Used in Memory Storage Devices and Computer Hardware:

• These days we are completely dependent on computers and mobiles, every piece of important data will be relying on the computer storages, but we know every system has its own capacity to store. So we turn around for the memory storage devices to secure a particular data. The data stored or available in the e-book gadgets and phones are stored in the electromagnetic format in the form of bytes and bits. 

• The computer hardware is also having magnetic tape and most of the computer hardware works on the principle of electromagnetism. Even in the early days of the invention of computers electromagnets had a huge role in the data storage of VCP and VCR.

The Electromagnets are Even Used in Communication Devices and Power Circuits:

• Without electromagnets, all communication systems and the devices such as the mobiles and the telephones we use to make phone calls over a long distance could not have taken place. 

• The electromagnetic pulses sent by the devices and the interaction between the signals make mobiles and telephones very handy, without which nothing can be done. Communication has gotten even more advanced and hence advanced electromagnets are used in most communication systems.

Did You Know?

• Unlike a regular magnet, we can switch on and off an electromagnet according to the requirements. The electromagnets work only with an external power source. The strength of the electromagnets can be varied from stronger to weaker depending on the amount of current flowing in the wires, it can be varied accordingly. 

• The electromagnets are also found useful in large industrial areas and they are even used by large Businesses that use machinery to do heavy lifting such as lifting cars or to move it to another location or even by scrapyards to separate iron and other ferrous metals from nonferrous materials.

• Japan is currently testing a 320 kilometre per hour (200 miles per hour) levitating train that utilizes electromagnets to hover and move around the entire place. 

• The U.S. Navy is also working with electromagnets and have performed high tech experiments with a futuristic electromagnetic rail gun weapon. The Navy has also used an electromagnetic catapult that has been used to launch planes off carrier decks.

We know that a force is something that can be felt but cannot be seen. We just know by Newton’s second law of motion that on applying force to the car, it starts accelerating. 

 

However, a new term comes into our knowledge and that is ‘pseudo force’, so do you know what Pseudo Force is?

 

Well! A frictional or inertial or an apparent force that acts on the object with mass ‘m’ in motion without regarding an inertial frame of reference. For thus we can consider a rotating frame reference.

 

Pseudo Force Meaning

The word ‘pseudo’ means something imaginary, fictitious, or does not exist, only we consider something. A force is something we apply in pushing, pulling, or rolling an object over the surface. 

 

When it comes to pseudo force, we are talking about an imaginary force. That doesn’t exist but we still consider it as the part to study the nature of forces in Physics. 

 

Define Pseudo Force

Let’s say there are two bodies viz: P and Q and they are sitting in an accelerated metro and R observes both of them from the platform. Here, if R draws a free body diagram of Q, it will have a net force that gives acceleration; however, when P draws a free body diagram or FBD for Q then for a body ‘P’,  Q is at rest so to counter the force shown by P,  Q needs a fictitious force in his frame and this fictitious force is nothing but the pseudo force.

 

Explain Pseudo Force

In the above statement, we said that a pseudo force is also called a fictitious force. A fictitious force arises when a frame of reference is accelerating when compared to a non-accelerating frame. Let’s suppose that a person is standing at a bus stop and he watches an accelerating car, he infers that when a force is exerted on the car and it is accelerating.

 

What happens next is, if the same person A sits in the car and watches another person B standing in his place at the bus stop, he observes that though no force acts on the standing person, still the person A observes that arbitrarily person B is moving along with his car but in the opposite direction. So, here  

 

Let’s consider another scenario where a man pushes a swing for his child, and the swing makes an oscillatory motion, so the force is acting on it that tries to reduce its speed, and eventually the swing comes to rest. So, here, a force is acting but we are not sure from which direction or what magnitude of force acts on the swing. So, for a child swinging, he feels that air is moving along with him, so it is a fictitious force again.

 

Let’s consider a basic pseudo force example to understand in a better way:

 

Pseudo Force Examples

Example 1: Let’s consider a scenario of a ball hung from the roof of a train using an inextensible string. No, if the train is at rest or is moving with a uniform speed in a straight line the string will remain in a vertical position and passengers infer that the total force acting on the ball is zero.

 

Let’s suppose that the train begins to accelerate, the string starts making an angle concerning the vertical while making the to-and-fro motion.  

 

In this situation, for a passenger, there are two forces, and they are not collinear; however;  the ball appears to remain in a state of equilibrium (as long as the acceleration of the train remains constant). In this type of condition, the concept of pseudo force is required.

 

 Example 2: Elevator scenario

Let us find out more about pseudo forces with real-time examples. We all got stuck in the elevator. When we are moving upwards in the elevator we feel heavy compared to going down.

 

Let us consider a  scenario where a person having mass m is standing on a weighing machine that is placed in a stationary elevator. The actual weight of a person is mg. The weighing machine offers a normal reaction N, the weight ‘mg’ is a reading of this machine. The motion of the elevator decides the weight of the man.

 

1. The apparent weight of the man will be the actual weight of the man when the elevator is stationary or moving with uniform velocity.

N−mg=m(0)

N=mg

 

2. When the elevator is moving upwards with an acceleration a, We observe that,

N−mg=ma

N=m(g+a)

 

We observed that the apparent weight of the man has become more than the actual weight.

 

3. When the elevator is moving downwards with an acceleration a. 

mg−N=ma

N = M(g−a)

 

Here, the apparent weight of the man has become less than the actual weight.

 

Pseudo Force Formula

Since pseudo force is an imaginary force like a frictional force , is always acts in the direction opposite to that of the direction of motion of an object. So, we indicate the formula for the pseudo force by a negative sign. So, here the formula goes:

 

FP = – ma…(1)

 

Here,

FP = pseudo force,(we used a subscript ‘p’ to distinguish it from the force we consider). It is also measured in N.

m = mass of the moving object. It is measured in Kg. 

a = acceleration caused by an object’s frame of reference when it is subjected to an external force. It is measured in ms⁻².

 

Pseudo Force Formula Explanation

The negative sign we used in equation (1) shows that the pseudo force always acts in the direction opposite to that of the acceleration of the object’s frame of reference. 

 

Is centrifugal and centripetal force always equal?

When the radial direction is concerned, the body will be at rest. When we are in the frame of reference, both forces are equivalent. Centripetal and centrifugal forces will not be equal when the body experiences radial acceleration.

 

Work Done by Pseudo Force

The work done by a pseudo force is zero as it acts to appear on the body. 

 

We can consider an example of thinking of picking a pile of bricks in our dreams, though we are applying the force here we are not doing it in actuality. So, here the actual work is done is zero, as Physics talks about facts and practical implications.

 

Conclusion

The article has covered the majority of insight about the Pseudo Force with examples that will help in understanding the topic.