Question

Calculate the charge density for the current density given 20sin x i + ycos z j at the origin. (a) 20t (b) 21t (c) 19t (d) -20t The question was posed to me in a job interview. Enquiry is from Continuity Equation in portion Electric Fields in Material Space of Electromagnetic Theory Select the correct answer from above options Electromagnetic Theory questions and answers, Electromagnetic Theory questions pdf, Electromagnetic Theory question bank, Electromagnetic Theory questions and answers pdf, mcq on Electromagnetic Theory pdf,electromagnetic theory book pdf,electromagnetic theory pdf notes,electromagnetic theory lecture notes,electromagnetic theory of light,maxwell electromagnetic theory,electromagnetic theory proposed by,electromagnetic theory engineering physics,electromagnetic theory nptel

Answer 1

Correct option is (b) 21t Explanation: Using continuity equation, the problem can be solved. Div(J) = – dρ/dt. Div(J) = 20cos x + cos z. At origin, we get 20cos 0 + cos 0 = 21. To get ρ, on integrating the Div(J) with respect to t, the charge density will be 21t.