Question

The figure below represents a section of a circular conductor of nonuniform diameter carrying a current of I = 4.50 A. The radius of cross-section A1 is r1 = 0.420 cm. (a) What is the magnitude of the current density across A1? 81.26 Incorrect: Your answer is incorrect. . What is the definition of the current density? A/m2 The radius r2 at A2 is larger than the radius r1 at A1. (b) Is the current at A2 larger, smaller, or the same? The current is larger. The current is smaller. The current is the same. Correct: Your answer is correct. . . (c) Is the current density at A2 larger, smaller, or the same? The current density is larger. The current density is smaller. The current density is the same. Correct: Your answer is correct. . . Assume A2 = 2A1. (d) Specify the radius at A2. Correct: Your answer is correct. . mm (e) Specify the current at A2. Correct: Your answer is correct. . A (f) Specify the current density at A2.

Answer 1

Currenrt density J = current/area

J = i/pi r^2

J = 4.5/(3.14 * 0.042^2)

J = 812.46 A/m^2