Lenz's Law And Conservation Of Energy
Chapter Name : Electromagnetic Induction |
Sub Topic Code : 101_12_06_05_01 |
Topic Name : Lenz's Law And Conservation Of Energy |
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Sub Topic Name : Lenz's Law And Conservation Of Energy |
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Introduction
The EMF induced in a
loop subjected to changing magnetic flux is said to produce a current which
opposes the changing flux.
Pre-Requisites:
Electromagnetic
Induction, Magnetic Flux, Faraday’s Law of Induction, Lenz’s Law, Conservation
of Energy
Activity:
Gather the devices
used in any one Faraday’s experiment to prove the law of electromagnetic
induction. See if the direction of current induced in the coil satisfies Lenz’s
Law.
Real Life Question:
What is the polarity
of EMF induced in a coil under changing magnetic flux?
Key Words / FlashCards
| Key Words | Definitions (pref. in our own words) |
|---|---|
| Lenz’s Law | The polarity of induced EMF is such that it produces a current which opposes the change in magnetic flux that produced it. |
Learning aids / Gadgets
| Gadgets | How it can be used |
|---|---|
| Electromagnetic Induction chart | To know about Electromagnetic Induction |
Real life uses :
Can help us to find the polarity of EMF induced in a wire under changing
magnetic field
Places to visit :
Physics lab
Practical examples around us
| Examples | Explainations |
|---|---|
| Electromagnetic Induction | Its effect in the physical world |
What you learn in Theory:
That the EMF induced
in a wire under changing magnetic field opposes the magnetic flux that caused
the EMF in the first place
What you learn in Practice:
That the EMF induced
in a wire under changing magnetic field opposes the magnetic field as required
by the Law of Conservation of energy. If the EMF would have supported the
magnetic field, then we could have constructed a Perpetual Motion Machine which
is not possible according to the Laws of thermodynamics.