Basics of Current: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Basics of Current. Understanding the underlying formula is key to arriving at the correct answer below:

In a conductor, free electrons are in constant random thermal motion. Due to this random orientation, for every electron moving in one direction, there's another moving in a roughly opposite direction, leading to a cancellation of their velocities. Therefore, the vector sum of these random velocities, which is the average thermal velocity, is zero. Both (A) and (R) are true, and (R) correctly explains (A).