Question
Download Solution PDFDrift velocity in metal is
This question was previously asked in
ESE Electronics 2014 Paper 1: Official Paper
Answer (Detailed Solution Below)
Option 3 : proportional to the mobility of an electron
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ST 1: UPSC ESE (IES) Civil - Building Materials
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Detailed Solution
Download Solution PDFConcept:
The drift velocity is directly proportional to the electric field, i.e.
Vd ∝ E
Vd = μE
The proportionality constant 'μ' defined as:
\(\mu = \frac{{{v_d}}}{E} = \frac{{q\tau }}{m}\)
Observation:
- Drift velocity is proportional to the mobility of the electron, i.e. more the mobility, the more will be the drift velocity.
- Drift velocity is directly proportional to the electric field applied.
- Drift velocity is inversely proportional to the mass of the electron.
Notes:
- Mobility defines how quickly can an electron move in metal or semiconductor under the influence of the electric field.
- When an electric field is applied, the electrons and holes are accelerated by it.
- The electron moving with a finite average velocity is called drift velocity.
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