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An Interpretation of the Two-Capacitor Paradox Based on the Field Point of View
New Phys.: Sae Mulli 2017; 67: 1450~1459
Published online December 29, 2017;
© 2017 New Physics: Sae Mulli.

Hongbin KIM, Youngrae JI*

Department of Physics Education, Seoul National University, Seoul 08826, Korea 
Correspondence to:
Received August 3, 2017; Revised October 23, 2017; Accepted October 30, 2017.
cc This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
In this paper, we present undergraduate students' explanation on the two-capacitor paradox, which may seem to violate the energy conservation law. We also suggest a way of explaining the paradox based on the concept of electromagnetic fields. Although many of the undergraduate students have learned the concept of Poynting vectors, they cannot provide a proper explanation of the energy flow through electromagnetic fields even when the circuit consists of simply two capacitors. We present an explanation that will help students to understand the mechanism of energy emission from and absorption by each capacitor through the electromagnetic fields.
PACS numbers: 01.40.Fk
Keywords: Electromagnetic fields, Poynting vector, Energy flow, Undergraduate physics, Two-capacitor paradox

April 2018, 68 (4)
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