Monday, September 06, 2010

Electronic Facts

1. Electrons in a pair spin in opposite directions, their opposite spins cause their magnetic fields to cancel each other.

2. Quartz Crystal: A slice of quartz grounded to a prescribed thickness that vibrates at a steady frequency when stimulated by electricity. The tiny crystal about 1/20th by 1/5th of an inch, creates the computer's heartbeat. It is piezoelectric, generate electricity when subjected to pressure.
Resistor symbol

Capacitor symbol3. Resistors are used to lower the level of current in a closed loop.





4. Capacitors are electronic components used for storing small amount of electricity. That explains how radios keep playing for a couple of seconds even after unplugging them.

5. Amplifiers are used to make weak signals stronger.Amplitude modulated signal stays on one exact frequency.

6. Frequency modulated signal is transmitted by changing its frequency.FM radio waves always stay on the same amplitude.

7. The electricity running through human's brain is of too small a magnitude to be measured by most electrical equipments.

8. To generate a  radio wave, electric field must be continuously changing.

9. Electronics is a branch of physics that deals with how electrons behave in vacuum or gases.Electricity is the group name of  energy possessed by energized electrons.

10. Electronic systems normally use relatively small amounts of  electric energy to process or transmit information.

11. Homes usually have AC supply.Electronic components have a transformer to convert AC to DC.

Electronic Terms

Boltzmann Constant:

In joules equals  1.3806503 × 10-23 (m2 kg s-2 K-1  ) or joules per kelvin


In electronvolts, the Boltzmann constant is 8.617 343(15) × 10−5 eV/K


Symbol: 
Used to define the relation between absolute temperature and the kinetic energy contained in each molecule of an ideal gas, a constant of proportionality for temperature and energy
http://en.wikipedia.org/wiki/Boltzmann_constant




Avogadro's Number:

The number of atoms needed such that the number of grams of a substance equals the atomic mass of the substance,

An Avogadro's number of substance is called a mole. For example, a mole of carbon-12 atoms is 12 grams, a mole of hydrogen atoms is 1 gram, a mole of hydrogen molecules is 2 grams, etc.

Faraday's constant:
It is the charge carried by one mole of electrons. There are 6.02214e23 electrons per mole of electrons. (Avogadro's number)
Each electron has a charge of 1.602177e-19 coulombs per electron.
So Faraday's constant is 1.602177e-19 coulombs per electron * 6.02214e23 electrons per mole of electrons = 9.64853e4 coulombs / mole of electrons.
This constant is useful to us when we are doing problems in electrolysis.