History and evolution of electronics

History and evolution of electronics

  1. In 1791 Luigi Galvani: Professor of anatomy (university of bologna) with the help of series of experiments showed the presence of electricity in animals (specifically frogs).
  2. In 1799 Charles coulomb: One famous scientist of the 18th century demonstrated that there existed a force between any two charges, this force could be either attractive force or repulsive force and this force is also influenced by the distance of separation between the two charges.
  3. In 1799 Allessandro Volta : An Italian scientist credited with the invention of battery. He was the first to develop a battery know as the voltaic cell that could produce electricity as a result of chemical reaction.
  4. In 1820, Hans Christian oersted showed that a magnetic field is associated whenever current flows through a conductor. To demonstrate this effect he connect a copper wire to the terminals of a battery and a switch and placed a magnetic compass near the wire. When the switch was close current started flowing in the wire and a deflection was seen in the compass indicating that current carrying conductor has an associated magnetic field.
  5. In 1827 George simon Ohm, a germen physicist derived the relation between the voltage applied (V), the current (I), and the resistance of a circuit. This is the famous and the most basic law Ohm’s law. It is given as V=IR.
  6. In 1831 Michael Faraday , a British scientist after the discovery by Oersted that a magnetic field is associated with the conductor carrying current, Faraday through a series of experiments discovered that the vice versa is possible i.e. current can be generated by using time varying magnetic field. This phenomenon was termed as the Electromagnetic induction which is the basic underlying principle of the working of generators.
  7. In 1864 James Clerk Maxwell, A British Physicist developed the electromagnetic field equations that today is referred to as Maxwell’s equations. He also formulated an important theory known as the electromagnetic theory of light, which told that electromagnetic waves travel in free space at the speed of light.
  8. In 1888 Heinrich Hertz, Based on the predictions of Maxwell’s electromagnetic theory wanted to experimentally verify the theory. He performed various experiments according to what Maxwell’s theory and successfully demonstrated to the world the effect of electromagnetic radiation through space .
  9. In 1895 Guglielmo Marconi put together the predictions of Maxwell and the experiments of Hertz to send electromagnetic signals through space and was successful in setting up the first transatlantic wireless communication system.
  10. In 1948, William Schockley, John Bardeen and Watter Brattain developed the transistor.
  11. Nikola Tesla: One great scientist without whom our today’s world would have been dark. Yes he invented alternating current (Popularly known as AC) and gave light to the world. He also has his name Tesla as the unit of magnetic field added to his credit.

Convert hexadecimal to decimal number

Convert hexadecimal to decimal number

We can convert hexadecimal to decimal by simply representing the given each digit of the given Hexadecimal number as sum of powers of 16, since for hexadecimal number system 16 is the base or radix. Here we first convert each individual hexadecimal digit separately and then add it together to get the final decimal equivalent. Detailed steps explaining the process of converting Hexadecimal to decimal, with illustrated examples of hexadecimal to decimal conversions.


How to Convert Hexadecimal to Decimal

Step 1: First we write down the given hexadecimal number separately and identify the LSD and MSD for hexadecimal numbers with only integer part and no fractional part.

Step 2: We then represent each digit of the given hexadecimal number as powers of 16, starting from 160 from right to left.

Step 3: We then evaluate the power of 16 values such as 160 is 1 and 161 is 16. And from the number system conversion table we can identify the decimal equivalent of individual hexadecimal digits such as for example the decimal equivalent of hexadecimal digit A is 10.

Step 4: We then multiply the decimal equivalent obtained from the number system table with the evaluated power of 16 values, and write it down as sum of products.

Step 5: We then add all the individual products and this sum total gives the final decimal equivalent of the given hexadecimal number.

The following show illustrated examples of hexadecimal to decimal converstions

Problem 1: Convert ( 2 5 A )16= ( ? )10

=  2 5 A
   ↑      ↑

= 2 x 162 + 5 x 161 + A x 160

= 2 x 256 + 5 x 16 +  10 x 1

= 512 + 80  + 10

= 602

Therefore  ( 2 5 A )16 =  ( 6 0 2 )10

Problem 2: Convert ( 2 0 D 0 )16= ( ? )10

=  2 0 D 0
    ↑        ↑
MSD       LSD

= 2 x 163 + 0 x 162 + D x 161+ 0 x 160

= 2 x 4096  + 0 x 256   + 13 x 16  + 0 x 1

= 8192  +  0  +  208  +  0

= 8400

Therefore  ( 2 0 D 0 )16 =  ( 8 4 0 0 )10

Problem 3:
 Convert ( F F F F )16= ( ? )10

=  F F F F 
    ↑        ↑
MSD      LSD

= F x 163 + F x 162 + F x 161+ F x 160

= 15 x 4096  + 15 x 256   + 15 x 16  + 15 x 1

=  61440 +  3840  +  240  +  15

= 65535

Therefore  ( F F F F )16 =  ( 6 5 5 3 5 )10

Problem 4: Convert ( A B C 0 )16= ( ? )10

=  A B C 0
= A x 163+ B x 162+ C x 161+ 0 x 160

= 10 x 4096  + 11 x 256+ 12 x 16 + 0 x 1

= 40960  +  2816  +  192 + 0  

= 43968

Therefore  ( A B C 0 )16 =  ( 4 3 9 6 8 )10

Difference between octal and hexadecimal


Difference between Octal and Hexadecimal

We have already studied the octal number system and hexadecimal number system and worked on few solved examples to understand the representation of octal numbers and the representation of hexadecimal numbers.

Octal vs Hexadecimal Comparison

Hexadecimal NumbersOctal Numbers
It uses 16 different symbols or digits for representing hexadecimal numbers, [0,1,2,3,4,5,6,7,8,9,A,B,C,D,E,F].Octal numbers use only 8 symbols or digits to represent all the octal numbers. Therefore, it can have digits from 0 to 7 only.
The radix or base for hexadecimal numbers is 16.The radix or the base for octal number is 8.
Easier to represent and remember large numbers.Easy to represent using octal number system but difficult to remember large numbers.
Example of Hexadecimal number: FF (Equivalent to Two hundred and fifty-five in decimal)Example of Binary number: 377 (Equivalent to Two hundred and fifty-five in decimal)
It takes 4 bits or 4 Binary digits to represent a single Hexadecimal digit.It takes only 3 bits or 3 Binary digits to represent an Octal digit.
Since the hexadecimal number system uses 16 digits, the arithmetic and logical operations could become complex.On the other hand, the Octal number system uses a lesser number of digits (8). This makes performing arithmetic and logic operations easy compared to the hexadecimal number system.
Representing large decimal numbers in the hexadecimal number system is easier.Representing large decimal numbers in octal becomes difficult and large.
octal vs hexadecimal


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