Michael Faraday, Group 4 SCIENCE

1. Michael Faraday,
GROUP 4
10th Grade

2. Michael Faraday
Michael Faraday was a French
physicist and chemist who is
best known for his discoveries
of electromagnetic induction
and of the laws of electrolysis.
His biggest breakthrough in
electricity was his invention of
the electric motor.
(1791 – 1867)

3. Apprenticeships and Early Studies in
Electricity
Humphry Davy was one of the leading chemists
of the day when Michael Faraday joined him
in 1812, having discovered sodium and
potassium and studying the decomposition
of muriatic (hydrochloric) acid that yielded
the discovery of chlorine. Davy and Faraday
began to interpret the molecular structure of
such chemicals, which would greatly
influence Faraday's ideas about electricity.

4. When Michael Faraday's
second apprenticeship
under Humphry Davy ended
in late 1820, Faraday
knew about as much
chemistry as anyone else at
the time, and he used this
newfound knowledge to
continue experiments in the
fields of electricity and
chemistry.
Apprenticeships and Early Studies in
Electricity

5. Michael Faraday is best known for his work regarding
electricity and magnetism. He built two devices to
produce what he called "electromagnetic rotations".
One of these, now known as the homopolar motor,
caused a continuous circular motion that was
engendered by the circular magnetic force around a
wire that extended into a pool of mercury wherein was
placed a magnet; the wire would then rotate around
the magnet if supplied with current from a chemical
battery.

6. Electromagnetic rotation experiment of Faraday, 1821, the
first demonstration of the conversion of electrical energy
into motion

7. Homopolar motor
A homopolar motor is a direct
current electric motor with two
magnetic poles, the conductors of
which always cut unidirectional
lines of magnetic flux by rotating a
conductor around a fixed axis so
that the conductor is at right
angles to a static magnetic field.

8. One of Michael Faraday first experiments
after discovering electromagnetic rotation
was attempting to pass a ray of polarized
light through an electrochemically
decomposing solution to detect the
intermolecular strains the current would
produce. However, throughout the 1820s,
repeated experiments yielded no results. It
would be another 10 years before Faraday
made a huge breakthrough in chemistry.

9. Electromagnetic
Induction

10. Michael Faraday carried out numerous experiments to
prove that electricity could be generated from
magnetism. He not only demonstrated electromagnetic
induction, but also developed a good conception of the
processes involved.
Electromagnetic or magnetic induction is the
production of an electromotive force (emf) across an
electrical conductor in a changing magnetic field.

11. One of the experiments
performed by Faraday in
that important year
featured a permanent
magnet and a
galvanometer connected
to a coil of wire wound
around a paper cylinder,
similar to those illustrated
in this tutorial. nationalmaglab.org/html5/MagLabU/source/electromagneticin
duction/electromagneticinduction.html

12. In this demonstration of
electromagnetic induction, the
mechanical energy of the moving
magnet is converted into
electricity, because a moving
magnetic field, entering a
conductor, induces current to flow
in the conductor.

13. Observe that
the voltmeter linked to
the coil only indicates
the presence of a
current when the
magnet is actually in
motion

14. magnetic field lines, depicted in blue,
emanating from the magnet, and how the
direction of the current (indicated in
black arrows) changes depending on
which way the magnet is moving.
When the north end of the magnet enters
the coil, a current is induced that travels
around the coil in a counterclockwise
direction; when the magnet is then
pulled out of the coil, the direction
reverses to clockwise.

15. the current produced
is stronger when the
magnet is moved
quickly rather than
gradually.

16. As indicated by the
voltmeter, greater
voltage can be induced
in coils made from a
larger number of turns of
wire.

17. The homopolar generator, also called the Faraday disk
is a DC electrical generator consisting of an
electrically conductive disc or cylinder rotating in a
plane perpendicular to a static magnetic field.
The first homopolar generator was developed by
Michael Faraday during his experiments in 1831
Homopolar Generator

18. How it works is two wires is attached
through a sliding contact to a
copper disc. By rotating the disc
between the poles of a horseshoe
magnet, he obtained a continuous
direct current, creating the first
generator. From his experiments
came devices that led to the
modern electric motor, generator,
and transformer.

19. Diamagnetism
In 1845, Faraday discovered that many
materials exhibit a weak repulsion from a
magnetic field: a phenomenon he
termed diamagnetism are repelled by a
magnetic field; an applied magnetic field
creates an induced magnetic field in them in
the opposite direction, causing a repulsive
force. In contrast, paramagnetic and
ferromagnetic materials are attracted by a
magnetic field

20. Faraday Cage
is an enclosure used to block
electromagnetic fields. A
Faraday shield may be formed
by a continuous covering of
conductive material, or in the
case of a Faraday cage, by a
mesh of such materials.
Faraday cage was invented by
Michael Faraday in 1836.

21. Michael Faraday continued his electrical experiments
throughout much of his later life. In 1832, he proved
that the electricity induced from a magnet, voltaic
electricity produced by a battery, and static electricity
were all the same. He also did significant work in
electrochemistry, stating the First and Second Laws of
Electrolysis, which laid the foundation for that field
and another modern industry. He later died in August
25, 1867