Problem 91 - A Complete Resource Book in Physics for JEE Main

Question

Which one of the following statement is incorrect? (A) A moving charged particle produced electric and magnetic field both. (B) Equipotential surface is always perpendicular to electric field. (C) Kirchhoff's junction law follows conservation of charge. (D) Electric field inside the conductor is always zero.

Step-by-Step Solution

Answer

All of the given options (A, B, C, and D) seem to be correct. There seems to be an error in the question, as none of the statements appear to be incorrect based on the fundamental concepts of electricity and magnetism.

Step 1: (Evaluating option A)

(Let's consider a moving charged particle. When a charged particle moves, it creates an electric field around it. Additionally, its motion through a magnetic field results in the generation of a magnetic field as well. Based on this understanding, option A is correct.)

Step 2: (Evaluating option B)

(An equipotential surface is a surface where the electric potential is the same at every point. The electric field is defined as the negative gradient of the electric potential. This means that the electric field lines are always perpendicular to the equipotential surfaces. Therefore, option B is also correct.)

Step 3: (Evaluating option C)

(Kirchhoff's junction law, also known as Kirchhoff's current law, states that the sum of currents entering a junction in a circuit is equal to the sum of currents leaving that junction. This principle follows the conservation of charge because charge cannot be created or destroyed but only redistributed within a circuit. Consequently, option C is correct.)

Step 4: (Evaluating option D)

(At the surface of a conductor, charges distribute themselves such that the electric field is perpendicular to the surface. Due to electrostatic forces being balanced inside the conductor, the electric field inside a perfect conductor is zero. In reality, conductors have some resistance, and there might be traces of electric fields. However, the statement is broadly accepted as true for ideal conductors. Therefore, option D is also correct.)

Step 5: (Conclusion)

(All of the given options (A, B, C, and D) seem to be correct. There seems to be an error in the question, as none of the statements appear to be incorrect based on the fundamental concepts of electricity and magnetism.)