Acessibilidade / Reportar erro

Perfectly conducting loop of wire moving through a uniform and stationary magnetic field

O movimento de uma espira condutora perfeita através de um campo magnético estacionário e uniforme

A conductive loop of wire moving with constant velo city in a magnetic field is one of the most used examples in physics textbooks in connection to the Faraday-Lenz law, highlighting the consistency of electromagnetism with the principIe of conservation of energy. It is frequently concluded that currents are not induced in a perfectly conducting loop because an induced current would have to be infinite and therefore would violate the principIe of energy conservation. ln this paper we discuss this problem and show that a model that includes the loop self-inductance prevents the divergence of the current and leads to results compatible with the conservation of energy.

Faraday-Lenz law; auto-inductance; electrical resistance; perfect conductor


Sociedade Brasileira de Física Caixa Postal 66328, 05389-970 São Paulo SP - Brazil - São Paulo - SP - Brazil
E-mail: marcio@sbfisica.org.br