Question

A positive charge is released and moves along an electric field line. This charge moves to a position of a) lower potential and lower potential energy. b) lower potential and higher potential energy. c) higher potential and lower potential energy. d) higher potential and higher potential energy.

Short answer

Based on the given information, when a positive charge is released in an electric field and moves along the field line, its position concerning potential and potential energy is: a) lower potential and lower potential energy

Step-by-step solution

Electric potential

The electric potential (V) at a point in an electric field is the amount of electric potential energy a charge at that point would possess per unit charge.

Potential Energy

The electric potential energy (U) that an electric charge has depends on the electric potential (V) at that point and the total charge (q). U = qV Now, let's analyze the motion of positive charge in an electric field:

Movement of positive charge

Positive charges always move from a region of higher potential to a region of lower potential along electric field lines. With this understanding of electric potential and potential energy, we can analyze each option:

Option a: Lower potential and lower potential energy

If the charge moves to a lower potential, the electric potential energy (U) will also decrease because U=qV. This matches the statement that positive charges move from higher potential to lower potential. So this option is correct.

Option b: Lower potential and higher potential energy

This option contradicts the relationship between potential and potential energy (U = qV). If the potential decreases, the potential energy must decrease. So this option is incorrect.

Option c: Higher potential and lower potential energy

This option also contradicts the relationship between potential and potential energy. If the potential increases, the potential energy must increase. And a positive charge does not move towards a higher potential. So this option is incorrect.

Option d: Higher potential and higher potential energy

As the positive charge should move to lower potential and potential energy, this option is also incorrect. So, the correct answer is: a) lower potential and lower potential energy.