Question

which property is used to identify the electric charge on an object

Answer 1

repulsion is the best method to identify electic charge

Answer 2

There are two types of charges . We call it as Positive charge and negative charge.

Electric charge is the property of an object that causes it to attract or repel from another charged object .
Gold leaf electroscope and  Pith ball electroscope are used to detect the charge on the  object.

The property on which we can find out  the presence of charge on object is:
---> Like charges repel
---> unlike charges attract.
For example :To identify the charge on electroscope. First we need to charge electroscope with known charge[let us say positive charge]. The leaves will get positively charged and move apart. Then touch the disc of electroscope with other object we need to test.