Rabu, 28 September 2011

electroscope


How did electroscope work.

An electroscope is an early scientific instrument that is used to find outabout the presence and magnitude of the electric charge on a body. It was the first electrical measuring instrument. The first electroscope, which was a pivoted needle called the versorium, was invented by a British physician called William Gilbert around the 1600s.
Electroscopes detect electric charges by the motion of a test object because of the Coulomb electrostatic force. The accumulation of enough charge to detect with an electroscope requires hundreds or thousands of volts, so electroscopes are only used with high voltage sources like static electricity and electrostatic machines. So basically an isnstrument that measures charge quantitatively is called an electrometer.
The kind of electroscope

 

Pith-ball electroscope

A pith-ball electroscope, invented by British weaver's apprentice John Canton in 1754, consists of a small ball of some lightweight nonconductive substance, originally pith, suspended by a silk thread from the hook of an insulated stand. In order to test the presence of a charge on an object, the object is brought near to the uncharged pith ball.  If the object is charged, the pith ball will be attracted to it.
Gold-leaf electroscope
 The gold-leaf electroscope was developed in 1787 by British clergyman and physics Abraham Bennet, as a more sensitive instrument than pith ball or straw blade electroscopes.


The example of electroscope and electrometer

                  Max Kohl          Henley Electrometer
              c. 1900               c. 18th century
Name : Luqyana salsabila wijaya
Class : 9D/15
`

Tidak ada komentar:

Posting Komentar