Michael Faraday

22 sep 1791 – 25 aug 1867 By:

B.RaGhaVenDer Goud,EEE-A, 3rd Year,

J.B Institute of Eng.. and Technology.

Faraday was a British chemist and physicist

who contributed significantly to the

study of electromagnetism and

electrochemistry.

Education and Early -Life Born on 22 September, 1791 in Newington Butts, England, UK. 3rd child of James and Margaret Faraday. Till 13 he received basic education. At 14, he was apprenticed to a local bookbinder George Riebau and studied himself for next 7 years.  In 1813, “Humphry Davy” appointed him to the job of chemical assistant at the Royal Institution. married Sarah Barnard on 12 June 1821.

. It is not an accident that Albert Einstein used to keep photos of three scientists in his office:  Isaac Newton,  James Clerk Maxwell,  and

Michael Faraday.

1821: Discovery of Electromagnetic Rotation. 1823: Gas Liquefaction and Refrigeration. 1825: Discovery of Benzene. 1831: Discovery of Electromagnetic Induction. 1834: Faraday’s Laws of Electrolysis. 1836: Invention of the Faraday Cage. 1845: Discovery of the Faraday Effect – a magneto-optical effect. 1845: Discovery of Diamagnetism as a Property of all Matter.

Michael Faraday’s Scientific Achievements and Discoveries

1821: Discovery of Electromagnetic Rotation.

 He found that by inducing an electric current on a wire,it obtained a magnetic force that could be plotted as it changed at different point around the wire.  Further experimentation showed that if you rotate the magnetized wire in a magnetic field a current is produced, a process known as electromagnetic induction.  By combining the two experiments he was able to change the amount of voltage output from an electrical source.

 This work led to the first generators, transformers and electric motors

Faraday’s electromagnetic rotation apparatus.

Electricity flows through the wires. The liquid in the cups is mercury, a good conductor of electricity. In the cup on the right, the metal wire continuously rotates around the central magnet as long as electric current is flowing through the circuit

1823: Gas Liquefaction and Refrigeration.

In 1802 John Dalton had stated his belief that all gases could be liquified by the use of low temperatures and/or high pressures.

Faraday provided hard evidence for Dalton’s belief by applying pressure to liquefy chlorine gas and ammonia gas for the first time.

The mechanical pumps could transform a gas at room temperature into a liquid. The liquid could then be evaporated, cooling its surroundings and the resulting gas could be collected and compressed by a pump into a liquid again, then the whole cycle could be repeated.

Showing that ammonia could be liquefied under pressure, then evaporated to cause cooling, led

to commercial refrigeration

Refrigiration: LNG Refrigiration Cycle

1825: Discovery of Benzene

Michael Faraday discovered benzene in the oily residue left behind from producing gas for lighting in London.

C₆H₆A model of a benzene molecule.

1831: Discovery of Electromagnetic Induction

Varying Magnetic Field causes Electricity to flow in an electric circuit. He shown that movement could be turned into electricity. Rotation (kinetic energy) is converted into electricity using electromagnetic induction.

Faraday's experiment showing induction between coils of wire

Liquid battery

small coil

Large

coil

galvanometer

World’s first Electric GeneratorFor producing continuous (pure) DC

voltage

Copper disk

Horseshoemagnet

brush

1834: Faraday’s Laws of Electrolysis.

 Faraday stated two laws on the basis of his studies on electrolysis:

1. Faraday’s first law

2.   Faraday’s second law:

according to biochemistry…Faraday's First Law of Electrolysis:

According to this law, the chemical deposition due to flow of current through an electrolyte is directly proportional to the quantity of electricity (coulombs) passed through it.i.e. mass of chemical deposition M α Q

M=ZQWhere, Z= electrochemical equivalent

Faraday's Second Law of Electrolysis:

According to this law, “if same quantity of electricity is passed through different electrolytes, then the amount of substances liberated at the respective of electrodes are in the ratio of their equivalent masses”.

W1/W2 = E1/E2

1836: Invention of the Faraday-cage

 when an electrical conductor becomes charged, all of the extra charge sits on the outside of the conductor. This means that the extra charge does not appear on the inside of a room or cage made of metal.

Faraday cages can also create dead zones for mobile communications.

Here a car’s metal body is acting as a Faraday Cage, protecting the occupants from

the electric discharge.

1845: Discovery of the Faraday Effect – a magneto-optical effect.

This effect showes that a magnetic field causes the plane of light polarization to rotate.

It is the first to link electromagnetism and light. Described fully by James Clerk Maxwell’s equations in 1864, which established that light is an electromagnetic wave.

when the contrary magnetic poles were on the same side, there was an effect produced on the polarized ray, and thus magnetic force and light were proved to have relation to each other…

Faraday effect

1845: Discovery of Diamagnetism as a Property of

all Matter Faraday discovered that all substances are diamagnetic.

Diamagnetism opposes the direction of an applied magnetic field.

For example, If you held the north pole of a

magnet near a strongly diamagnetic substance, this

substance would be pushed away by the magnet.

:AWARDS:1832 : COPLEY MEDAL

1835 : ROYAL MEDAL

1838 : COPLEY MEDAL

1846 : RUMFORD MEDAL ROYAL MEDAL

1866: ALBERT MEDAL

:HEAVENLY ABODE:1867: On Aug 25th Michael Faraday left for the heavenly abode at Hampton Court, Middlesex, England. at Highgate

cemetery, London