Question

Please help and do it step by step all parts of questions and use:
T = time(s)
I=current (amps)
Q=net charge on object (Coulombs)
N=no electrons (and write if added or removed from object and how)
E=elementary charge

Two copper wires of diameter 1 mm and 2 mm are joined end to end in a circuit.
a) Calculate the ratio of the mean drift velocities of the electrons in the two wires if the same current passes through each of them.
b) In which wire will the electrons move faster and why?

Answer 1

you changed the area by 4x.
current=driftvelocity*electrondensitypervolume*area
so if electron density/volume is the same, and area of one is 4x, then drift velociyt is 1/4 because current is constant.