A positive point test charge is to be placed at a location labeled P along a straight…
PHYSICS · Multi-part · CBSE · Physics · Electric Charges and Fields · Electric Charges and Fields
Problem
A positive point test charge is to be placed at a location labeled P along a straight line between two fixed point charges in each of the three independent configurations described below. In every case the separation between the fixed charges is 8cm.
• Configuration I: +q and +q are at the endpoints; point P is exactly midway between them.
• Configuration II: +q and −q are at the endpoints; point P is exactly midway between them.
• Configuration III: +2q is on the left and +q on the right; point P is 2cm to the right of the +2q along the line joining the charges.
(a) Rank the magnitudes of the net electric force on the test charge at point P for the three configurations, from greatest to least. Use the symbols “>”, “=”, or “<” in your ranking.
(b) Provide a qualitative justification for your ranking, explicitly addressing both charge sign and distance factors in each configuration.
(c) Identify any configuration(s) in which the net electric force on the test charge is zero. Explain your reasoning.