Displacement Current — Predicted 2026

AI-Predicted Question Angles for UPSC 2026

Based on trend analysis, current affairs, and recurring themes in Displacement Current.

Conceptual understanding of $I_d$ vs $I_c$

high

This is a perennial favorite for conceptual questions. NEET often tests the fundamental distinction between physical flow of charge (conduction current) and the magnetic effect of a changing electric field (displacement current). Questions might ask which one causes Joule heating, which exists in vacuum, or which one is responsible for EM wave propagation. A clear understanding of these differences is crucial for avoiding trap options.

Calculation of displacement current in a capacitor

medium

Numerical problems involving displacement current are most likely to be set in the context of a charging or discharging capacitor. Students might be asked to calculate $I_d$ given the rate of change of electric field or electric flux, or simply to state its value when the conduction current is known ($I_d = I_c$). These questions test the application of the formula $I_d = epsilon_0 rac{dPhi_E}{dt}$ and the relationship $I_d = I_c$ for capacitors. Unit conversions and basic differentiation skills will be important.

Role of displacement current in Maxwell's equations and EM waves

high

Displacement current is a cornerstone of Maxwell's equations and the theory of electromagnetic waves. Questions might focus on which Maxwell's equation incorporates displacement current (Ampere-Maxwell law) and its significance in allowing EM waves to propagate in vacuum. Understanding how a changing electric field generates a magnetic field (via $I_d$) and vice-versa (Faraday's law) is fundamental to this topic and frequently tested.