What do you call a charging method that charge an object without actually touching the object to any other charged object?

Solution:

The process of charging the uncharged object by bringing another charged object near to it, but not touching it, is called charging by induction.

Consider an uncharged metal sphere and negatively charged plastic rod as shown in below figure (1). If we bring the negatively charged plastic rod near to the uncharged sphere as shown in below fig (2), charge separation occurs.

The process of charging the uncharged object by bringing another charged object near to it, but not touching it, is called charging by induction.

The positive charges in the sphere get attracted towards the plastic rod and move to one end of the sphere that is closer to the plastic rod. Similarly, negative charges get repelled from the plastic rod and move to another end of the sphere that is farther away from the plastic rod. Thus, the charges in the sphere rearrange themselves in a way that all the positive charges are nearer to the plastic rod and all the negative charges are farther away from it.

If this sphere is connected to a ground through the wire, free electrons of the sphere at the farther end flow to the ground. Thus, the sphere becomes positively charged by induction. If the plastic rod is removed, all the positive charges spread uniformly in the sphere.