question_answer

Copper contains \[8.4\times {{10}^{28}}\] free electrons/\[{{m}^{3}}\]. A copper wire of cross-sectional area \[7.4\times {{10}^{-7}}\]\[{{m}^{2}}\] carries a current of 1 A. The electron drift speed is approximately:

A) \[{{10}^{-8}}\text{m/s}\]                             

B) \[{{10}^{3}}\text{m/s}\]

C) \[\text{1}\,\text{m/s}\]                                               

D) \[{{10}^{-4}}\text{m/s}\]