Final answer:
The electric potential is highest near a positive charge because the potential is proportional to the magnitude of the charge and becomes more positive as the distance to the charge decreases.
Step-by-step explanation:
The electric potential has the highest positive value when you look near a positive charge. This is because the potential of an electric field created by a point charge is directly proportional to the magnitude of the charge itself and inversely proportional to the distance from the charge. In physics, we often visualize the electric potential similar to a landscape of hills and valleys, where hills represent areas of high positive electric potential (near positive charges) and valleys represent areas of low negative electric potential (near negative charges).
With this analogy in mind, if we place a positive test charge in the vicinity of another positive charge, the test charge would be at a high potential point, akin to a hilltop. It would require work to bring the test charge closer to the positive charge due to the repulsive force between like charges. Therefore, the potential energy of the system increases as the positive test charge approaches another positive charge.
When we are far from any charge, the potential is nearly zero. This is because at a significantly large distance, the effects of the electric fields originating from the charges become negligible. Conversely, when near a negative charge, the potential would be negative, as you would be situated in a 'valley' which represents an area of low potential. Thus, the correct answer to the question is option a) Near a positive charge.