Question

Suppose that you have a rod that is positively charged, a rod that is negatively charged and a stand that allows rotation. if you are handed a rod of unknown charge-state, could you determine if it has a positive charge, a negative charge or if it is neutral? explain

Answer 1

Yes

Step-by-step explanation:

The law of electrostatics states that like charges repel, while unlike charges attract. When you place either of the charged rods on the rotating stand, bring the rod of unknown charge-state in its neigbourhood. If there is repulsion, it shows that both rods have same charge, while attraction would show opposite charges. If the rod is neutral, there would be no reaction, since net charge is zero.

Answer 2

Yes, you can. Remember that in electrophysics, opposite charges attract. Since there is a stand of rotation, it allows the rod with both ends having opposite charges to rotate. Now, if you place the unknown charge near the set-up, it could turn clockwise or counterclockwise. When the set-up turns such that the negative end is approaching the unknown charge, that charge must be positive. Otherwise, the unknown charge is negative.