The key difference between Faraday’s law and Lenz law is that Faraday’s law indicates the magnitude of the emf produced, whereas Lenz law indicates the direction that current will flow.
Faraday’s law is a basic law of electromagnetism that predicts how a magnetic field tends to interact with an electric circuit, producing an electromotive force. Lenz law or Lenz’s law is a law that states the direction of the electric current induced in a conductor through a changing magnetic field is similar to the magnetic field created by the induced current that is opposite to the changes in the initial magnetic field.
CONTENTS
1. Overview and Key Difference
2. What is Faraday’s Law
3. What is Lenz Law
4. Faraday’s Law vs Lenz Law in Tabular Form
5. Summary – Faraday’s Law vs Lenz Law
What is Faraday’s Law?
Faraday’s law is a basic law of electromagnetism that predicts how a magnetic field tends to interact with an electric circuit, producing an electromotive force. This law is used as the fundamental operating principle of transformers, inductors, and other types of electrical motors, generators, and solenoids. After the discovery of Faraday’s law, one of its aspects was formulated as the Maxwell-Faraday equation at a later time. Moreover, we can derive the equation for Faraday’s law using the Maxwell-Faraday equation and Lorentz force.
Faraday’s law can be described as a single equation that describes two different phenomena: first, the motional emf that is generated by a magnetic force on a moving wire, and second is the transformer emf that is generated by an electric force due to a changing magnetic field.
The Maxwell-Faraday equation tends to describe the fact that a spatially varying electric field can always accompany a time-varying magnetic field, whereas Faraday’s law indicates that there is emf on the conductive loop upon the magnetic flux through the surface that is enclosed by the loop which varies in time.
What is Lenz Law?
Lenz law or Lenz’s law is a law that states the direction of the electric current induced in a conductor through a changing magnetic field is similar to the magnetic field created by the induced current that is opposite to the changes in the initial magnetic field. This law was named after the physicist Emil Lenz in 1834.
The Lenz law is a qualitative law that tends to specify the direction of induced current; however, it states nothing about its magnitude. Moreover, this law predicts the direction of many effects in electromagnetism, e.g. the direction of voltage induced in an inductor or wire loop by a changing current or the drag force of eddy currents that are exerted on moving objects in a magnetic field.
What is the Difference Between Faraday’s Law and Lenz Law?
Faraday’s law and Lenz law are important laws in electrochemistry. The key difference between Faraday’s law and Lenz law is that Faraday’s law indicates the magnitude of the emf produced whereas Lenz’s law indicates the direction that current will flow.
Below is a summary of the difference between Faraday’s law and Lenz law in tabular form for side by side comparison.
Summary – Faraday’s Law vs Lenz Law
Faraday’s law is a basic law of electromagnetism that predicts how a magnetic field tends to interact with an electric circuit, producing an electromotive force. Lenz’s law is a law that states the direction of the electric current induced in a conductor through a changing magnetic field is similar to the magnetic field created by the induced current that is opposite to the changes in the initial magnetic field. The key difference between Faraday’s law and Lenz law is that Faraday’s law indicates the magnitude of the emf produced, whereas Lenz’s law indicates the direction that current will flow.
Reference:
1. Shepard, Kayla, et al. “Faraday’s Law.” Discovering the World, 7 Mar. 2013.
Image Courtesy:
1. “Induction experiment” By J. Lambert – Downloaded 2009-08-06 from Arthur William Poyser (1892) Magnetism and electricity: A manual for students in advanced classes, Longmans, Green, & Co., New York, p.285, fig.248 on Google Books. The drawing is signed Lambert, J. (Public Domain) via Commons Wikimedia
2. “Lenz law demonstration” By Keministi – Own work (CC0) via Commons Wikimedia