how can we know whether a substance carry positive charge or negative charge?
how can we know whether a substance carry positive charge or negative charge?
Hi Chinubdml!
The polarity of charge on an object can be identified by the electroscope, by the following method.
Charge the electroscope by the induction method. A rod of opposite polarity to that required on the electroscope can be used for charging it. The rod is brought near to the cap so that the leaf diverges by the amount desired, and the electroscope is momentarily earthed by touching it with a finger, keeping the rod in position. The rod is then removed, leaving the electroscope charged. (If the charged rod used is ebonite, this leaves a positively charged electroscope, if a glass rod is used then the result is a negatively charged electroscope).
Now bring the object of unknown charge down from a good height and move it slowly towards the cap of the electroscope. A charge of the same kind as that on the electroscope will cause an increase in leaf divergence, while a charge of the opposite kind will cause a decrease in leaf divergence when the object is brought near to the electroscope.
Cheers!!
Hi Chinubdml!
The polarity of charge on an object can be identified by the electroscope, by the following method.
Charge the electroscope by the induction method. A rod of opposite polarity to that required on the electroscope can be used for charging it. The rod is brought near to the cap so that the leaf diverges by the amount desired, and the electroscope is momentarily earthed by touching it with a finger, keeping the rod in position. The rod is then removed, leaving the electroscope charged. (If the charged rod used is ebonite, this leaves a positively charged electroscope, if a glass rod is used then the result is a negatively charged electroscope).
Now bring the object of unknown charge down from a good height and move it slowly towards the cap of the electroscope. A charge of the same kind as that on the electroscope will cause an increase in leaf divergence, while a charge of the opposite kind will cause a decrease in leaf divergence when the object is brought near to the electroscope.
Cheers!!
