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Question #42715
The Question
A straight conducting wire is uniformly accelerated along its length (the direction) with a constant acceleration . A uniform constant electric field of magnitude is applied along the direction within the wire. The conduction electrons have mass , charge , and an average relaxation time between successive collisions with the lattice. Assume the standard Drude model where electrons lose their entire drift momentum relative to the lattice upon each collision, and the steady-state drift velocity is given by . In the non-inertial frame of the accelerating wire, let be the average rate of heat dissipation per electron, and be the average rate at which the electric field does work on a single electron. Which of the following expressions correctly represents the difference ? (All given quantities are in standard SI units)
Options
- A.
- B.
- C.
- D.
Check Your Answer
Correct Answer
Step-by-Step Solution
Explanation
How the Examiner Thinks
Intuition_Breaker
Train your brain to resist "obvious" answers that are designed to deceive your intuition.
Concepts Behind This Question
Drift Velocity Mechanism|Work against Conservative Force|Frame of Reference
Why This Question Is Tricky
Common Mistakes
This question tests the application of the Work-Energy Theorem in a non-inertial reference frame within a dissipative system.
A common trap is assuming that Joule heating is always exactly equal to the work done by the electric field (), leading students to incorrectly choose 0.
By placing the conductor in an accelerating frame, students must recognize that the pseudo force also does mechanical work on the electrons during their ballistic flight between collisions.
This additional kinetic energy is thermalized upon impact with the lattice, meaning the total heat dissipated exceeds the work done by the conservative electric field alone.
Quick Facts About This Question
Question Information
| Subject | Physics |
| Chapter | Current Electricity - Class 12 |
| Concept | Drift Velocity Mechanism |
| Difficulty | 8 |
| Cognitive Load | 7 |
| Target Solve Time | 160 sec |
| Access | Free |