It is the flow of electric charges through the conductor.
Explanation
Electric current is defined as the ordered flow of electric charge through a cross-section of a conductor. In solid metallic conductors, the atoms are fixed in a lattice structure, and the charge carriers responsible for conduction are free electrons.
Option Analysis
- It is the accumulation of static charges at one end. is incorrect: The accumulation of static charges relates to electrostatics. Electric current requires the dynamic movement of charges, not their stationary accumulation.
- It is the flow of electric charges through the conductor. is correct: Electric current is the rate of flow of electric charges through a conductor. When a potential difference is applied across a metallic conductor, free electrons drift towards the positive terminal, constituting a current.
- It is the vibration of atoms without charge movement. is incorrect: The vibration of atoms about their mean positions is a thermal phenomenon related to the temperature of the material, not the flow of electric current.
- It is the flow of protons in the direction of the field. is incorrect: In metallic conductors, protons are bound within the atomic nuclei and do not move. The flow of current is due to the movement of negatively charged electrons. The direction of conventional current is opposite to the flow of electrons, but protons themselves do not flow.
Key Takeaway
Electric current in metals consists of the flow of free electrons. While the actual charge carriers are negative electrons moving from low to high potential, conventional current is defined as flowing from high to low potential.