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the drift velocity is 1m/s under an external electric field electron drift slowly inside the conductor what is the relaxation time |
| Answer» <html><body><p><strong>Explanation:</strong></p><p>In physics a drift velocity is the average velocity attained by charged particles, such as electrons, in a material due to an electric field. In general, an electron in a conductor will <a href="https://interviewquestions.tuteehub.com/tag/propagate-592982" style="font-weight:bold;" target="_blank" title="Click to know more about PROPAGATE">PROPAGATE</a> randomly at the Fermi velocity, resulting in an average velocity of zero. Applying an electric field adds to this random <a href="https://interviewquestions.tuteehub.com/tag/motion-1104108" style="font-weight:bold;" target="_blank" title="Click to know more about MOTION">MOTION</a> a small net flow in one direction; this is the drift.</p><p></p><p>Drift velocity is proportional to current. In a resistive material it is also proportional to the magnitude of an <a href="https://interviewquestions.tuteehub.com/tag/external-981194" style="font-weight:bold;" target="_blank" title="Click to know more about EXTERNAL">EXTERNAL</a> electric field. Thus Ohm's law can be explained in terms of drift velocity. The law's most elementary expression is:</p><p></p><p>{\displaystyle u=\mu E,}u=\mu E,</p><p>where u is drift velocity, μ is the material's electron mobility, and E is the electric field. In the MKS system these quantities' units are m/s, m2/(V·s), and V/m, respectively.</p><p></p><p>When a potential difference is applied across a conductor, <a href="https://interviewquestions.tuteehub.com/tag/free-465311" style="font-weight:bold;" target="_blank" title="Click to know more about FREE">FREE</a> electrons gain velocity in the direction opposite to the electric field between successive collisions (and lose velocity when traveling in the direction of the field), thus acquiring a velocity component in that direction in addition to its random <a href="https://interviewquestions.tuteehub.com/tag/thermal-706916" style="font-weight:bold;" target="_blank" title="Click to know more about THERMAL">THERMAL</a> velocity. As a result, there is a definite small drift velocity of electrons, which is superimposed on the random motion of free electrons. Due to this drift velocity, there is a net flow of electrons opposite to the direction of the field.</p></body></html> | |