Discussion
Ohm’s law when applied to electromagnetic phenomenon gives the following expression :
Answer: A
The field form of Ohm's law is \(\overline{J} = \sigma\overline{E}\).
In electromagnetic theory, Ohm's law is written at each point of a conductor: the current density is proportional to the electric field, with the conductivity \(\sigma\) as the constant of proportionality. Integrating it over a uniform wire of length L and cross-section A gives the circuit form \(V = IR\), with \(R = L/\sigma A\).
V = IR is the circuit law, not the expression for electromagnetic fields the question asks for. \(\sigma = \overline{J}\overline{E}\) multiplies where it should divide, and \(\overline{E} = \overline{J}\sigma\) puts the conductivity where the resistivity \(1/\sigma\) belongs.
Post your comment
Please log in or register to post a comment.
Examination Categories
- SSC Exams
- Banking Exams
- Teaching Exams
- Civil Services Exams
- Railways Exams
- Engineering Recruitment Exams
- Defence Exams
- State Government Exams
- Police Exams
- Insurance Exams
- Nursing Exams
- Other Government Exams
- NRA CET
- PG Entrance Exams
- Campus Placement
- MBA Entrance Exams
- CUET and UG Entrance
- Judiciary Exams
- Regulatory Body Exams
- Software Development