7. An 8-gauge iron wire with n=1.7 x 10^29 m-3 is 1.99 mm in diameter d can carry a maximum current of 24 A. Find the drift speed of the electrons at this maximum current?
1 Answer
May 9, 2018
Drift speed
#v_d=I/(n|e|A)#
where#n# is the density of charge carriers,#|e|# is modulus of charge on carrier and#A# is area of cross section of wire.
In iron wire charge carriers are electrons. Inserting various values in SI units we get
#v_d=24/((1.7 xx 10^29)(1.60xx10^-19)(pi((1.99/10^3)^2)/4))#
#=>v_d=2.84xx10^-4\ ms^-1#
