Module 6 : PHYSICS OF SEMICONDUCTOR DEVICES
Lecture 33 : Hall Effect
Example 6
  A long strip of material of width $ w= 1$ cm and thickness $ d=1$ mm is subjected to a magnetic field along a direction parallel to the edge $ d$. A current of 1 A flows in the strip parallel to its length. The mobility of the carriers (of density $ 2.5\times 10^{22}$ per m $ ^3$) is 5 m $ ^2$/V-s.
(1)    Determine the magnitude and direction of the net electric field.
(2)    If $ B=0.1$ T, calculate the potential difference $ V_H$ between the opposite points of the strip parallel
  to the width $ w$.
  Solution
  The current $ I = JA = nevwd$ which gives the drift velocity as
 
$\displaystyle v = \frac{I}{nedw} = 25 \ \ {\rm m/s}$
  Thus the electric field parallel to the length is
 
$\displaystyle E_{\parallel} = \frac{v}{\mu}= \frac{25}{5}= 5\ \ {\rm V/m}$
 

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