Lenz's Law - Revision history

Ljang8: Final Edit

2025-12-07T04:03:34Z

Final Edit

← Older revision		Revision as of 00:03, 7 December 2025
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	Note: remember the magnetic field for a dipole!		Note: remember the magnetic field for a dipole!

	[[File:~~LenzLawFigure~~.~~jpg~~]]		[[File:LenzLawFigureA.png]]
	Graphic created by Nicole Romer, Digitalized by Lucia Jang		Graphic created by Nicole Romer, Digitalized by Lucia Jang

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	'''Solution'''		'''Solution'''
	A)-y, clockwise B)+y, counterclockwise C)+y, counterclockwise D)-y, clockwise		A)-y, clockwise B)+y, counterclockwise C)+y, counterclockwise D)-y, clockwise
	[[File:~~lenzlaw1~~.png]]		[[File:LenzLawSolutionA.png]]

	The magnetic field in this graphic is decreasing at a rate of 5.0mT/s. What is the direction of the current in the circle of wire?		The magnetic field in this graphic is decreasing at a rate of 5.0mT/s. What is the direction of the current in the circle of wire?

	[[File:LenzLawSolutions.~~jpg~~]]		[[File:LenzLawSolutions.png]]
	Graphic created by Nicole Romer, Digitalized by Lucia Jang		Graphic created by Nicole Romer, Digitalized by Lucia Jang

Ljang8 at 03:47, 7 December 2025

2025-12-07T03:47:28Z

← Older revision		Revision as of 23:47, 6 December 2025
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	Note: remember the magnetic field for a dipole!		Note: remember the magnetic field for a dipole!

	[[File:~~LenzLaw~~.jpg]]		[[File:LenzLawFigure.jpg]]
	Graphic created by Nicole Romer		Graphic created by Nicole Romer, Digitalized by Lucia Jang

	Use <math> B_i</math> and <math> B_f</math> to find <math>-{\frac{dB}{dt}} </math> & use the RHR to determine the direction of the current.		Use <math> B_i</math> and <math> B_f</math> to find <math>-{\frac{dB}{dt}} </math> & use the RHR to determine the direction of the current.
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	'''Solution'''		'''Solution'''
	A)-y, clockwise B)+y, counterclockwise C)+y, counterclockwise D)-y, clockwise		A)-y, clockwise B)+y, counterclockwise C)+y, counterclockwise D)-y, clockwise
			[[File:lenzlaw1.png]]

	The magnetic field in this graphic is decreasing at a rate of 5.0mT/s. What is the direction of the current in the circle of wire?		The magnetic field in this graphic is decreasing at a rate of 5.0mT/s. What is the direction of the current in the circle of wire?

	[[File:~~hm235~~.jpg]]		[[File:LenzLawSolutions.jpg]]
			Graphic created by Nicole Romer, Digitalized by Lucia Jang

	'''Solution'''		'''Solution'''

Ljang8 at 23:17, 6 December 2025

2025-12-06T23:17:37Z

← Older revision		Revision as of 19:17, 6 December 2025
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	In summary, whenever there is a change in magnetic flux in a conducting loop, the charge is balanced by the induction of a magnetic field. The integral of B * n remains constant.		In summary, whenever there is a change in magnetic flux in a conducting loop, the charge is balanced by the induction of a magnetic field. The integral of B * n remains constant.



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	Picture 4:		Picture 4:
	As the magnet leaves the coil, the magnetic flux through the coil decreases, triggering an induced current. According to Lenz’s Law, this current flows in a direction that tries to maintain the original flux—creating a north pole at the bottom of the coil, again opposing the magnet’s motion. This produces an upward magnetic force that slows the fall (again, acceleration is less than g).		As the magnet leaves the coil, the magnetic flux through the coil decreases, triggering an induced current. According to Lenz’s Law, this current flows in a direction that tries to maintain the original flux—creating a north pole at the bottom of the coil, again opposing the magnet’s motion. This produces an upward magnetic force that slows the fall (again, acceleration is less than g).



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	This simulation demonstrates electromagnetic induction using a movable bar magnet, a coil of wire, and measurement tools such as voltmeters and field indicators. Users can observe how changes in magnetic flux generate an induced emf, and how the direction of the induced current follows Lenz’s Law. The simulation also allows adjustment of magnet strength, coil turns, and speed, giving a clear visual explanation of flux, induction, and opposition fields.		This simulation demonstrates electromagnetic induction using a movable bar magnet, a coil of wire, and measurement tools such as voltmeters and field indicators. Users can observe how changes in magnetic flux generate an induced emf, and how the direction of the induced current follows Lenz’s Law. The simulation also allows adjustment of magnet strength, coil turns, and speed, giving a clear visual explanation of flux, induction, and opposition fields.



	=== Right Hand Rule ===		=== Right Hand Rule ===

Ljang8: /* Computational Model */

2025-12-06T23:16:50Z

Computational Model

← Older revision		Revision as of 19:16, 6 December 2025
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	[https://phet.colorado.edu/en/simulations/faradays-electromagnetic-lab Try the simulation on PhET]		[https://phet.colorado.edu/en/simulations/faradays-electromagnetic-lab Try the simulation on PhET]

			This simulation demonstrates electromagnetic induction using a movable bar magnet, a coil of wire, and measurement tools such as voltmeters and field indicators. Users can observe how changes in magnetic flux generate an induced emf, and how the direction of the induced current follows Lenz’s Law. The simulation also allows adjustment of magnet strength, coil turns, and speed, giving a clear visual explanation of flux, induction, and opposition fields.

	=== Right Hand Rule ===		=== Right Hand Rule ===

Ljang8 at 23:16, 6 December 2025

2025-12-06T23:16:04Z

← Older revision		Revision as of 19:16, 6 December 2025
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	In summary, whenever there is a change in magnetic flux in a conducting loop, the charge is balanced by the induction of a magnetic field. The integral of B * n remains constant.		In summary, whenever there is a change in magnetic flux in a conducting loop, the charge is balanced by the induction of a magnetic field. The integral of B * n remains constant.



	~~==Theory==~~

	===Mathematical Model===		===Mathematical Model===
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	Picture 4:		Picture 4:
	As the magnet leaves the coil, the magnetic flux through the coil decreases, triggering an induced current. According to Lenz’s Law, this current flows in a direction that tries to maintain the original flux—creating a north pole at the bottom of the coil, again opposing the magnet’s motion. This produces an upward magnetic force that slows the fall (again, acceleration is less than g).		As the magnet leaves the coil, the magnetic flux through the coil decreases, triggering an induced current. According to Lenz’s Law, this current flows in a direction that tries to maintain the original flux—creating a north pole at the bottom of the coil, again opposing the magnet’s motion. This produces an upward magnetic force that slows the fall (again, acceleration is less than g).


			===Computational Model===

			Explore Lenz’s Law interactively with the PhET simulation linked below:

			[https://phet.colorado.edu/en/simulations/faradays-electromagnetic-lab Try the simulation on PhET]

	=== Right Hand Rule ===		=== Right Hand Rule ===
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	This procedure works because a current in a closed loop always produces a magnetic field following the right-hand rule. Lenz’s Law determines which direction that magnetic field must point; the right-hand rule then determines how the charges must circulate to produce it.		This procedure works because a current in a closed loop always produces a magnetic field following the right-hand rule. Lenz’s Law determines which direction that magnetic field must point; the right-hand rule then determines how the charges must circulate to produce it.



	~~==Computational Model==~~

	~~Explore Lenz’s Law interactively with the PhET simulation linked below:~~

	~~[https://phet.colorado.edu/en/simulations/faradays-electromagnetic-lab Try the simulation on PhET]~~

Ljang8 at 23:14, 6 December 2025

2025-12-06T23:14:04Z

Show changes

Ljang8 at 22:34, 6 December 2025

2025-12-06T22:34:04Z

Show changes

Ljang8 at 22:19, 6 December 2025

2025-12-06T22:19:17Z

← Older revision		Revision as of 18:19, 6 December 2025
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	[[File:Crossproductcasado.png]]		[[File:Crossproductcasado.png]]

			=== Right Hand Rule for Lenz's Law ===

			To determine the direction of the induced current in a loop, the right-hand rule is applied after identifying the direction of the induced magnetic field. Since Lenz’s Law states that the induced current will create a magnetic field that opposes the change in magnetic flux, the first step is to decide whether the external flux is increasing or decreasing, and whether it points into or out of the page. Once the direction of the induced magnetic field is known, the right-hand rule gives the corresponding direction of current.

			Point your thumb in the direction of the induced magnetic field (the direction required to oppose the change in flux). The curl of your fingers shows the direction of the induced current around the loop. A thumb pointing out of the page corresponds to a counterclockwise current, while a thumb pointing into the page corresponds to a clockwise current.

			This procedure works because a current in a closed loop always produces a magnetic field following the right-hand rule. Lenz’s Law determines which direction that magnetic field must point; the right-hand rule then determines how the charges must circulate to produce it.


	==Examples==		==Examples==

Ljang8 at 03:06, 1 December 2025

2025-12-01T03:06:52Z

← Older revision		Revision as of 23:06, 30 November 2025
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	[[File:hm235.jpg]]		[[File:hm235.jpg]]


	'''Solution'''		'''Solution'''

Ljang8: /* Example 2: Medium */

2025-11-24T20:15:12Z

Example 2: Medium

← Older revision		Revision as of 16:15, 24 November 2025
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	An magnet is moving through a copper tube (velocity drawn). Find the direction of -dB/dt and the direction of the induced current. Remember to use the right hand rule.		An magnet is moving through a copper tube (velocity drawn). Find the direction of -dB/dt and the direction of the induced current. Remember to use the right hand rule.

			Draw/write the direction of <math>-{\frac{dB}{dt}} </math>, as well as the induced current for each of these scenarios (as viewed from above).
			Note: remember the magnetic field for a dipole!

	[[File:LenzLaw.jpg]]		[[File:LenzLaw.jpg]]
	Graphic created by Nicole Romer		Graphic created by Nicole Romer

			Use <math> B_i</math> and <math> B_f</math> to find <math>-{\frac{dB}{dt}} </math> & use the RHR to determine the direction of the current.
			Note:<math>-{\frac{dB}{dt}} </math> is equal to <math> B_i - B_f</math>

	'''Solution'''		'''Solution'''

	A)-y, clockwise B)+y, counterclockwise C)+y, counterclockwise D)-y, clockwise		A)-y, clockwise B)+y, counterclockwise C)+y, counterclockwise D)-y, clockwise