Magnetism

Magnetism - Magnetism is a force of attraction or replusion that acts at a distance. It is due to a magnetic field, which is caused by moving electrically charged particles or is inherent in magnetic objects such as a magnet.

Magnetism - A magnet is an object that exhibits a strong magnetic field and will attract materials like iron to it. Magnets have two poles, called the north (N) and south (S) poles. Two magnets will be attacted by their opposite poles, and each will repel the like pole of the other magnet. Magnetism has many uses in modern life.

Current Electricity

Electric Current - The Electric current is a flow of electric charge through a conductive medium.

In electric circuits this charge is often carried by moving electrons in a wire. It can also be carried by ions in an electrolyte, or by both ions and electrons such as in a plasma.

The SI unit for measuring the rate of flow of electric charge is the ampere, which is charge flowing through some surface at the rate of one coulomb per second. Electric current is measured using an ammeter.

Static Electricity

Static electricity is an excess of electric charge trapped on the surface of an object. The charge remains until it is allowed to escape to an object with a weaker or opposite electrical charge, such as the ground, by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, which flows through wires or other conductors and transmits energy.

Light

Light is a type of energy which propagates as electromagnetic waves. In the spectrum of electromagnetic waves, light has place between ultraviolet and infrared region.

Some Facts About Light

•    Electromagnetic waves are transverse waves, therefore, light is also transverse wave.
•    Wave nature of light explains; rectilinear propagation of light, reflection of light, refraction of light, interference of light, diffraction of light and polarization of light.
•    The happenings in physics like Photoelectric Effect and Compton Effect can not be explained on the basis of wave nature of light. These phenomenons are explained on the basis of quantum theory of light, explained by Albert Einstein.
•    The quantum theory of light, considers light as a packet or bundle of energy, these energy packets are called photons. Photon associates with it as Energy E; where E = hv
•    Light has dual nature and behaves as a particle as well as wave.
•    Speed of Light was first calculated by Roemer in 1678 AD.
•    Speed of light is maximum in vacuum, which is equivalent to 3x108 m/s.

Thermodynamics

First Law of Thermodynamics

The first law of thermodynamics is the application of the conservation of energy principle to heat and thermodynamic processes:

The change in internal energy of a system is equal to the heat added to the system minus the work done by the system.

Mathematically, ΔU (Change in Internal Energy) = Q (Heat added to or drawn from the system) – W (Work done by the system)

Heat

Heat may be defined as energy in transit from a high temperature object to a lower temperature object.

Some Characteristics of Heat and Mathematical Equivalent

•    Heat is also defined as the transfer of kinetic energy from one medium or object to another, or from an energy source to a medium or object.

•    The heat transfer can occur in three ways: radiation, conduction, and convection.

•    The standard unit of heat in the International System of Units (SI) is the calorie (cal).

•    One calorie is defined as the amount of energy transfer required to raise the temperature of one gram of pure liquid water by one degree Celsius, provided the water temperature is higher than the freezing point and lower than the boiling point.

•    Sometimes the kilocalorie (kcal) is specified as a unit of heat; 1 kcal = 1000 cal. This is the also called diet calorie.

•    The amount of heat contained in a body depends upon the mass of the body.

•    If W is work performed and Heat produced is H, then W/H = J or W = JH, where J is a constant called mechanical equivalent of heat. The value of J is 4.186 Joule / Calorie. This means if 4.186 Joule of work is done, 1 Calorie of heat is consumed.

Sound Waves

•    Sound is a mechanical wave that results from the back and forth vibration of the particles of the medium through which the sound wave is moving.
•    If a sound wave is moving from left to right through air, then particles of air will be displaced both rightward and leftward as the energy of the sound wave passes through it.
•    The motion of the particles is parallel (and anti-parallel) to the direction of the energy transport. This is what characterizes sound waves in air as longitudinal waves.
•    The mechanical vibrations which can be said as sound are able to travel through all forms of matter i.e. solids, liquids and gases. The matter which allows the sound to travel through it is called the medium.
•    Sound cannot travel through a vacuum.

Wave

Wave- A wave can be described as a disturbance that travels through a medium from one location to another location without the transport of matter.

Types of Waves
Waves can be said of two types – 1. Mechanical Wave and 2. Non – Mechanical Wave

Simple Harmonic Motion

Periodic Motion: Any motion which repeats itself at regular intervals of time is called Periodic Motion or Harmonic Motion. Some of the examples of periodic motion are a rocking chair, a bouncing ball, a vibrating tuning fork, a swing in motion, the Earth in its orbit around the Sun, and a water wave.

•    The interval of time for a repetition, or cycle, of the motion is called a period.
•    The number of periods per unit time is called the frequency.

Thus, the period of the Earth’s orbit is one year, and its frequency is one orbit per year. A tuning fork might have a frequency of 1,000 cycles per second and a period of 1 millisecond (1 thousandth of a second).

Elasticity

Elasticity – The elasticity is the ability of a solid to return to its original shape or form after being subject to strain. Most solid materials display elasticity, up to a load point called the elastic limit; loads higher than this limit cause permanent deformation of the material.

Elastic Limit- The elastic limit is the maximum value of deforming force upto which a material displays elastic properties and above which a material losses its elastic properties.

Viscosity

Viscous Forces- These are forces which has tendency to oppose relative motion between different layers of liquid or gases.

Viscosity – Viscosity is the characteristic of a liquid due to which it opposes the relative motion between its various layers.

•    Viscosity is applicable to both liquid and gases.
•    The viscosity of a liquid is because of cohesive forces between layers.
•    Viscosity is liquid is less than viscosity of gases.
•    Solid has no viscosity.

Surface Tension

Cohesive Forces- Cohesive forces are the intermolecular forces, for example; hydrogen bonding and Van der Waals forces which cause a tendency in liquids to resist separation. These forces which are attractive forces exist between molecules of the same material. For example, rain falls as droplets, and not as fine mist, since water has strong cohesion hence its molecules pulls tightly together and droplets are formed. The cohesive force tends to bring closer molecules of a liquid, by making them comparatively large clusters which owes to molecules' dislike for its surrounding.

Floatation

Archimedes' Principle

•    The Archimedes' Principle is named after Archimedes of Syracuse
•    He discovered the law in 212 B.C.
•    The Archimedes' Principle states that any object, wholly or partially immersed in a fluid, is buoyed up by a force equal to the weight of the fluid displaced by the object.

Mathematically, the Archimedes' principle can be stated as Buoyancy = weight of displaced fluid.

Pressure

Pressure- Pressure is defined as force per unit area. The standard unit for pressure is the Pascal (Pa) or Newton per square meter (N/m2).

For an object placed on a surface, the force exerted on the surface by the object is the weight of the object, but in different orientations it might have a different area in contact with the surface and therefore exert a different pressure.

Gravitation

Gravitation – Gravitation oftentimes also termed as Gravity is a force which found among all material objects in the universe. For any two objects or particles having non-zero mass, the force of gravity tends to attract them toward each other. Gravity works on objects of all sizes, be these subatomic particles or clusters of galaxies.

Work, Energy and Power

Work - When a force acts upon an object and displaces it from its original position, it is said that work was done upon the object. There associates three key component to work - force, displacement, and reason or source.

Motion

Scalars - Scalars are quantities that are fully described by a magnitude (or numerical value) alone.

Examples of Scalar Quantities - mass, length, temperature, energy, pressure, volume, electric charge, space-time interval, invariant mass

Vectors - Vectors are quantities that are fully described by both a magnitude and a direction.

Name and Symbols of Different Physical Terms, Descriptions and SI Units

Base quantity	Symbol	Description	SI unit
Length	l	The one dimensional extent of an object.	metre (m)
Matter	m	The amount of matter in an object.

Important Physics Discoveries in Chronology Order

• 1687 - Laws of motion and law of gravity: Newton
• 1782 - Conservation of matter: Lavoisier 
• 1785 - Inverse square law for electric charges confirmed: Coulomb 
• 1801 - Wave theory of light: Young

Inventions, Inventor, Country and Year

• Adrenaline: (isolation of) John Jacob Abel, U.S., 1897.
• Aerosol can: Erik Rotheim, Norway, 1926.
• Air brake: George Westinghouse, U.S., 1868.
• Air conditioning: Willis Carrier, U.S., 1911.