What do you mean by engineering?
Most simply, the art of directing the great sources of power in nature for the use and the convenience of people. The application of scientific and mathematical principles to practical ends such as the design, manufacture, and operation of efficient and economical structures, machines, processes, and systems.
What do you mean by telecommunication?
The science and technology of communication at a distance by electronic
Transmission
What is electronics?
elctron+dynamics is electronics, means this is a study of the behavior(dynamic) of
electrons in semi conductors.
What is electrical?
Any thing Related to or associated with electricity.
What is the difference between the terms Electrical and Electronics?
Electrical relates to the development and delivery of the electrical energy to the various devices that perform specific functions in a given environment. Example: The alternator in your car that series of wires delivers electrical power / energy to various components (radio, the computer that monitors / controls operation of the engine) in today’s cars.
Where as "Electronics" relates more to the complex functions performed within a given device, more often now days by circuits comprised of many micro electronic sub components that make up the structure of a single micro electronic component. Example: a typical CPU chip would / could contain thousands of individual transistor circuits within a device no bigger that the size of your small finger nail with room to spare.
In Electronics we deal with voltages upto 20 volts and in electrical we have voltages 110+, electronics uses DC only.
Continuous function is a function for which, intuitively, small changes in the input result in small changes in the output. Otherwise, a function is said to be discontinuous. A continuous function with a continuous inverse function is called discontinuous. An intuitive though imprecise (and inexact) idea of continuity is given by the common statement that a continuous function is a function whose graph can be drawn without lifting the chalk from the blackboard. if M(t) denotes the amount of money in a bank account at time t, then the function jumps whenever money is deposited or withdrawn, so the function M(t) is discontinuous.
The standard deviation of a probability distribution, random variable, or population or multistep of values is a measure of the spread of its values. The standard deviation is usually denoted with the letter _ (lower case sigma). It is defined as the square root of the variance. The standard deviation is the most common measure of statistical dispersion, measuring how widely spread the values in a data set are. If many data points are close to the mean, then the standard deviation is small; if many data points are far from the mean, then the standard deviation is large. If all the data values are equal, then the standard deviation is zero.
Normal distribution, also called the Gaussian distribution, is an important family of continuous probability distributions, applicable in many fields. Each member of the family may be defined by two parameters, location and scale: the mean ("average", μ) and variance (standard deviation squared) _2, respectively. The standard normal distribution is the normal distribution with a mean of zero and a variance of one.
Correlation, (often measured as a correlation coefficient) , indicates the strength and direction of a linear relationship between two random variables.
Isotopes are any of the different forms of an element each having different atomic mass (mass number). Isotopes of an element have nuclei with the same number of protons (the same atomic number) but different numbers of neutrons. Therefore, isotopes have different mass numbers, which give the total number of nucleons—the number of protons plus neutrons. (Uranium-235 Uranium-238)
LASER is an acronym for Light Amplification by Stimulated Emission of Radiation.
A typical laser emits light in a narrow, low-divergence monochromatic (single colored, if the laser is operating in the visible spectrum), beam with a well-defined wavelength. In this way, laser light is in contrast to a light source such as the incandescent light bulb, which emits light over a wide area and over a wide spectrum of wavelengths.
Laser consists of a gain medium inside a highly reflective optical cavity, as well as a means to supply energy to the gain medium. The gain medium is a material (gas, liquid, solid or free electrons) with appropriate optical properties. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time passing through the gain medium. Typically, one of the two mirrors, the output coupler, is partially transparent. The output laser beam is emitted through this mirror. Light of a specific wavelength that passes through the gain medium is amplified; the surrounding mirrors ensure that most of the light makes many passes through the gain medium, stimulating the gain material continuously. Part of the light that is between the mirrors, passes through the partially transparent mirror and escapes as a beam of light. The process of supplying the energy required for the amplification is called pumping.
The energy is typically supplied as an electrical current or as light at a different wavelength. A typical pump source is a flash lamp or perhaps another laser. Most practical lasers contain additional elements that affect properties such as the wavelength of the emitted light and the shape of the beam.
Zeroth law of thermodynamics If two thermodynamic systems are in thermal equilibrium with a third, they are also in thermal equilibrium with each other. First law of thermodynamics for a thermodynamic cycle the sum of net heat supplied to the system and the net work done by the system is equal to zero.( energy cannot be created or destroyed)
Second law of thermodynamics is an expression of the universal law of increasing entropy, stating that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium. (In an isolated system, a process can occur only if it increases the total entropy of the system.) Third law of thermodynamics As a system approaches absolute zero, all processes cease and the entropy of the system approaches a minimum value. It can be concluded as 'If T=0K, then S=0' where T is the temperature of a closed system and S is the
entropy of the system.
Newton's laws of motion
First law: law of inertia "An object will stay at rest or continue at a constant velocity unless acted upon by an external unbalanced force".
Second law: the net force on a particle is proportional to the time rate of change of its linear momentum: F = d[mv] / dt. Momentum is the product of mass and velocity.
When the mass is constant, this law is often stated as F = ma (the net force on an object is equal to the mass of the object multiplied by its acceleration).
Third law: "Every action has an equal and opposite reaction".
Calorie is a unit heat: the amount of heat required to raise the temperature of a gram of water by 1 °C (from 14.5 °C to 15.5 °C)
One joule is the work done, or energy expended, by a force of one Newton moving one meter along the direction of the force. This quantity is also denoted as a Newton meter with the symbol N·m.
Nuclear fusion is the process by which multiple atomic particles join together to form
a heavier nucleus. It is accompanied by the release or absorption of energy. Nuclear fusion occurs naturally in stars. It takes considerable energy to force nuclei to fuse, even those of the lightest element, hydrogen. This is because all nuclei have a positive charge (due to their protons), and as like charges repel, nuclei strongly resist being put too close together. Accelerated to high speeds (that is, heated to thermonuclear temperatures), however, they can overcome this electromagnetic repulsion and get close enough for the attractive nuclear force to be stronger, achieving fusion. The fusion of lighter nuclei, creating a heavier nucleus and a free neutron, will generally release more energy than it took to force them together-an exothermic process that can produce self-sustaining reactions.
Nuclear fission is the splitting of the nucleus of an atom into parts (lighter nuclei) often producing free neutrons and other smaller nuclei, which may eventually produce photons (in the form of gamma rays). Fission of heavy elements is an exothermic reaction which can release large amounts of energy both as electromagnetic radiation and as kinetic energy of the fragments (heating the bulk material where fission takes place). Fission is a form of elemental transmutation because the resulting fragments are not the same element as the original atom. The products of nuclear fission are radioactive and remain so for significant amounts of time, giving rise to a nuclear waste problem.
BASIC ELECTRONICS
Superconductivity is a phenomenon occurring in certain materials at extremely low temperatures, characterized by exactly zero electrical resistance and the exclusion of the interior magnetic field. The electrical resistivity of a metallic conductor decreases gradually as the temperature is lowered. However, in ordinary conductors such as copper and silver, impurities and other defects impose a lower limit. Even near absolute zero a real sample of copper shows a non-zero resistance. The resistance of a superconductor, on the other hand, drops abruptly to zero when the material is cooled below its "critical temperature". An electric current flowing in a loop of superconducting wire can persist indefinitely with no power source.
Transponder: An automatic device that receives, amplifies, and retransmits a signal on a different frequency (see also broadcast translator).
Pull-up resistors are resistors used in the design of electronic logic circuits to ensure that inputs to logic systems settle at expected logic levels if external devices are disconnected. Pull-up resistors may also be used at the interface between two different types of logic devices, possibly operating at different power supply voltages.
The idea of a pull-up resistor is that it weakly "pulls" the voltage of the wire it's connected to towards 5V (or whatever voltage represents a logic "high"). However, the resistor is intentionally weak (high-resistance) enough that, if something else strongly pulls the wire toward 0V, the wire will go to 0V.
DIODE
The directionality of current flow most diodes possess is sometimes generically called the rectifying property. The most common function of a diode is to allow an electric current to flow in one direction (called the forward biased condition) and to block it in the opposite direction (the reverse biased condition).
V-I, characteristic curve is related to the transport of carriers through the so called depletion layer or depletion region that exists at the p-n junction between
differing semiconductors. When a p-n junction is first created, conduction band
(mobile) electrons from the N-doped region diffuse into the P-doped region where
there is a large population of holes (places for electrons in which no electron is
present) with which the electrons “recombine”. When a mobile electron recombines
with a hole, both hole and electron vanish, leaving behind an immobile positively
charged donor on the N-side and negatively charged acceptor on the P-side. The
region around the p-n junction becomes depleted of charge carriers and thus behaves
as an insulator.
However, the depletion width cannot grow without limit. For each electron hole
pair that recombines, a positively-charged dopant ion is left behind in the Ndoped
region, and a negatively charged dopant ion is left behind in the P-doped
region. As recombination proceeds and more ions are created, an increasing electric
field develops through the depletion zone which acts to slow and then finally stop
recombination. At this point, there is a “built-in” potential across the depletion zone.
If an external voltage is placed across the diode with the same polarity as the built-in
potential, the depletion zone continues to act as an insulator preventing a significant
electric current. This is the reverse bias phenomenon. However, if the polarity of the
external voltage opposes the built-in potential, recombination can once again proceed
resulting in substantial electric current through the p-n junction. For silicon diodes,
the built-in potential is approximately 0.6 V. Thus, if an external current is passed
through the diode, about 0.6 V will be developed across the diode such that the Pdoped
region is positive with respect to the N-doped region and the diode is said to be
“turned on” as it has a forward bias.
I–V characteristics of a P-N junction diode (not to scale).
A diode’s I–V characteristic can be approximated by four regions of operation (see
the figure at right).
At very large reverse bias, beyond the peak inverse voltage or PIV, a process called
reverse breakdown occurs which causes a large increase in current that usually
damages the device permanently. The avalanche diode is deliberately designed for use
in the avalanche region. In the Zener diode, the concept of PIV is not applicable. A
Zener diode contains a heavily doped p-n junction allowing electrons to tunnel from