Electric Charge...

In the diagram, three point charges (labeled 1, 2 and 3) are shown, along with the electric field around them. Which charge(s) is/are positive?

An electron and a proton are both released from rest 1 meter from a large stationary negative charge, considering only the force from the large stationary negative charge on the proton and electron. Which of the following is true?

Electric lines of force about a positive point charge are:

Electric charge is measured in

The charge is negative, then the electric lines of forces are 

The force acting between two point charges kept at a certain distance is $$5$$N. Now the magnitudes of charges are doubled and distance between them is halved, the force acting between them is _________ N.

Coulomb's law relates two charges and distance between them describing the electric force as being:

Electric lines of force about negative point charge are

The electric field inside a conductor.

The force between two charges $$2\mu C$$ and $$4\mu C$$ is $$24 N$$, when they are separated by a certain distance in free space. The forces if, $$(a)$$ distance between them is doubled and $$(b)$$ distance is halved are :