Question

A silver wire of cross section (1 , text(mm)^2) carries a current of (2 , text(A)). Find the magnitude of current density in the wire.

a) (0.002 , text(A/mm)^2)

b) (0.002 , text(A/m)^2)

c) (0.2 , text(A/mm)^2)

d) (0.2 , text(A/m)^2)

Answer 1

The magnitude of the current density in the silver wire carrying a current of 2 A and having a cross-sectional area of 1 mm^2 is 0.2 A/m^2.

Step-by-step explanation:

To find the magnitude of the current density in the wire, we need to divide the current by the cross-sectional area of the wire. The cross-sectional area of the wire is given as 1 mm2. Since the current is given as 2 A, the magnitude of the current density is given by:

J = I / A = 2 A / 1 mm2 = 2 A / 0.001 m2 = 2000 A/m2.

Therefore, the correct answer is option (d) 0.2 A/m2.