Notes, summaries, assignments, exams, and problems for Physics

Electromagnetics Fundamentals

Electromagnetics is the study of electric and magnetic phenomena and their engineering applications.

Fundamental Forces

The four fundamental forces of nature are the nuclear, weak-interaction, electromagnetic, and gravitational force.

Electric Charge Concepts

One coulomb: amount of charge accumulated in one second by a current of one ampere.

1 coulomb represents the charge on ~ 6.241 x 10¹⁸ electrons.

Coulomb's Law

The force exerted by one point charge on another acts along the line joining the charges. It varies inversely as the square of the distance separating the charges and is proportional to the product of the charges. The force is repulsive if the charges have the same sign and attractive if the charges have opposite... Continue reading "Fundamentals of Electromagnetics and Field Theory" »

Understanding Electrical Principles and Circuits

Static Electricity Fundamentals

When an atom becomes an ion, it becomes charged. When two insulating materials are rubbed together (e.g., wool and a plastic rod), electrons move from one material to another (as protons cannot move). This process results in one material becoming negatively charged and the other positively charged. Once charged, these materials can attract uncharged objects and objects with an opposite charge.

Understanding Electrical Sparking

A significant charge builds up on one object due to electrons being rubbed off by another. If a large enough charge accumulates, the voltage becomes sufficiently high to ionize the air molecules. This allows electrons to jump to earth, causing... Continue reading "Electrical Principles: Circuits, Static & Quantities" »

Tema 2

TEMA 2.High middle ages(1001-1300) and late m.A(1300-1485).Ongoing Expansion of islamic faith.Anglo-Sxon england invaded by William ,duke of Normandy.They Took literal possessions.Anglosazon=>Norman->Feudalism.Feudalism:complez social organisation based on functions and jiearchies. Functions: Oratores,bellatores,laboratores.Hierarchical: form superior to inferior According to essential degree.Defining features of the english medieval Period:-Resistance to monarcha´s feudal power.-Instability of political Power.-Pope´s authority also contested(Thomas becket´s murder in Canterbury)-Origin of some genuine institutions(oxford university, cambridge...)-Population Increase+developement of cities as centres of production and Commerce-

Sound:

Pressure waves produced when an object vibrates at a frequency between 20 Hz and 20000 Hz and there is a material medium that sound can travel through.

Fundamentals of Waves: Chapters 14 & 16

Mechanical vs. Electromagnetic Waves

Waves are broadly classified based on their requirement for a medium to travel:

Mechanical Waves

Mechanical waves require a medium (such as air, water, or solids) to travel.

• Examples: Sound waves, ocean waves, and waves traveling through springs.

Electromagnetic Waves (EM Waves)

Electromagnetic waves do not require a medium to travel; they can propagate through a vacuum.

• Examples: Radio waves, microwaves, infrared radiation, visible light, X-rays, and gamma rays.

Transverse Waves vs. Longitudinal Waves

Longitudinal

P–N Junction Diode Fundamentals

A p–n junction diode is constructed from a semiconductor crystal, typically silicon, although germanium and gallium arsenide are also utilized. Impurities are added to create two distinct regions. One side, called the n-type semiconductor, contains negative charge carriers (electrons). The other side, the p-type semiconductor, contains positive charge carriers (holes).

When these two materials (n-type and p-type) are joined, a momentary flow of electrons occurs from the n-side to the p-side. This results in a third region where no mobile charge carriers are present. This area is known as the depletion region due to the absence of free electrons and holes.

The diode's terminals are connected to the n-type and... Continue reading "P-N Junction Diode Construction and Biasing" »

What are gas behavior laws?

Any of several statements of physics and chemistry relating to the behavior of gases: such as Boyle's law and Charles' law.

Describe Boyle’s law and Charles’ Law and explain an example of each.

Charles's law (also known as the law of volumes) is an experimental gas law that describes how gases tend to expand when heated. Example: It's a warm sunny day. You are careful not to pump in too much air into your inflatable raft. In spite of that, if you leave it outside the pool, it could well pop as air inside it heats up and expands. The solution is to pump it while the raft is in the pool; then, leave it in the pool until you actually start using it. Deflate it immediately after use. Boyle’s law states that the pressure

Literary Naturalism

Literary naturalism contains an explicit comprehensive philosophy of our human place in the universe. Naturalism suggests that we humans are animals living in a material universe which has no supernatural power, except as a concept of our minds. We humans, animals, are governed by the same natural laws and forces that control all other beings and objects. We have no control over what happens to us.

There are several sources and causes of naturalistic philosophy, but one of the most relevant ones is the development of the physical sciences. It has traditionally been assumed that all phenomena could be explained by natural laws. These laws determine all things that happen, their causes and effects. Similarly, 19th-century social... Continue reading "Literary Naturalism and the Lost Generation: A Critical Analysis" »

The History of Parachutes

Early Attempts

The first known attempt at parachuting occurred in Cordova, Spain, in 852. Abbás Ibn Firnás jumped from a tower with a large cloak, but suffered injuries upon landing. Leonardo da Vinci also proposed the use of parachutes in the 15th century.

The First Practical Parachute

The first practical parachute was invented in 1783 by Louis-Sébastien Lenormand. In 1785, Jean Pierre Blanchard successfully used a parachute to save a dog from a fall. In 1793, he became the first person to successfully use a parachute for a human descent.

Parachutes in Aviation

Parachutes became a standard part of hot air balloon equipment in the 19th century. After World War I, they were adopted as safety systems for pilots and passengers... Continue reading "The Evolution of Parachutes: From Ancient Attempts to Modern Safety Systems" »