List of top Physics Questions on Electric Charge asked in JKCET

The property which differentiates two kinds of charges is called
What happens when a glass rod is rubbed with silk?
Two charges $Q_1$ and $-Q_2$ are separated by a distance $r$. The charges attract each other with a force $F$. What is the new force between the charges if the distance is cut to one-fourth and the magnitude of each charge is doubled?
X is a substance which does not allow the flow of charges through it but permits them to exert electrostatic forces on one another through it. Identify X.
Infinite charges of magnitude $q$ each are lying at $ x=1,2,4,8,... $ metre on $X$-axis. The value of intensity of electric field at point $ x=0 $ due to these charges will be