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Faraday’s Law & Lenz’s Law. Presenter: LIM XINYU.

01. THEORY. 02. Content. FARADAY’S LAW. 03. LENZ’S LAW.

Lenz’s Law and Faraday’s Law: The way a changing magnetic field interacts with a loop of conductor. Conductors carry current generate magnetic field.

Faraday’s Law:. Introduction: Relates the rate of change of magnetic flux through a loop to the magnitude of the electro-motive force induced in the loop. Electromotive force (EMF) → Potential difference across the unloaded loop Faraday’s Law of Induction: Describes how an electric current produces a magnetic field How a changing magnetic field generates an electric current in a conductor. Magnetic induction: electric motors, generators and transformers.

Example:. Observations: Rest or near: No voltage Moving toward: Some voltage Passes through the middle: Voltage changes in sign Passes out & away: voltage (opposite direction).

Move towards the coil (N Pole) → End of the coil (N Pole) Move away from the coil (N Pole) → End of the coil (S Pole).

Example:. The Coil Repulses the Magnet üWW,ELECTRlCALTECHNOLOGY.ORS The Coil Attracts the Magnet W/WELECTRICALTECHNOLCGY.ORG Fig I.A Fig I.B.

Example: Apply faraday’s law to find the induced voltage or EMF across a coil with 100 turns that is located in a magnetic field and that is changing a rate of 5Wb/s. Ans: Number of turns = 100 Magnetic field changing rate = 5Wb/s ? = ? ∆?/∆ t ε = 100X5 ε = 500V#.

Faraday’s Law → magnitude of the EMF produced Electric current can be induced in a loop by changing magnetic field. Lenz’s Law → the direction that current flow oppose the change in flux which produced it. Induced current always flows in 1 direction Formula Equation: Move number of turns of coil, greater the deflection..

References:. Khan Academy. (N.D) What is Faraday's Law? Available at: https://www.khanacademy.org/science/physics/magnetic-forces-and-magnetic-fields/magnetic-flux-faradays-law/a/what-is-faradays-law [Accessed: 14 November 2021] Cadence | PCB Design & Analysis. (N.D). Lenz Law vs. Faraday’s Law: How Do They Govern Crosstalk and EMI? Available at: https://resources.pcb.cadence.com/blog/2020-lenz-law-vs-faradays-law-how-do-they- govern-crosstalk-and-emi [Accessed: 14 November 2021].