Question

An aluminum wire of density dimeter 0.24 cm is connected in series of copper wire of dimeter 0.16 cm. The wire carry electric current of 10 A. Find current density and drift velocity

Answer 1

Answer:

Explanation:

=> current density in aluminum wire  :

Radius of aluminum wire = 0.24/2 = 1.2 ×10^-3 m  

Cross sectional area of aluminum = πr2 =  

(3.14) ×(1.2×10-3)^2 = 4.5 ×10^-6 m2

Current density in Aluminum J= I/A

J = 10 / 4.5 x 10^-6

J = 2.22 x 10^6 A/m^2

=> drift velocity of electrons in copper wire :

Radius of copper = 0.8 ×10^-3 m

Cross sectional area = (3.14) ×(0.8×10-3)^2 = 2.01 ×10^-6 m2

v_d = l / neA

v_d = 10 / 10^9 x 1.6 x 10^-19 x 2.01 x 10^-6

v_d = 3.1 x 10^-4 m/s

Thus,  current density in aluminum wire and drift velocity of electrons in copper wire is 2.22 x 10^6 A/m^2  and 3.1 x 10^-4 m/s respectively.