account for Lenzs Law in terms of conservation of energy and relate it to the production of back emf in motors
below is from jacaranda:
Lenzs law states: an induced emf always gives rise to a current that creates a
magnetic filed that opposes the original change in flux through the circuit. Which
means that an current would be induced in the direction opposite to the cause.
The principal of energy states: energy cannot be created nor destroyed, but it can be transformed from one form to another.
If a changing flux in a coil would produce a magnetic flux in the same direction as the original change of flux, then it would lead to a greater change in flux threading the coil, which in turn would lead to an even greater change in flux, and the induced current would continue to increase. However this cannot occur, as if is happens, then we would be creating energy which violets the principle of conservation of energy.
but it doens't really answer the dot point, it doesn't say why it does not violet the conservation of energy...it just stops there saying that it cant....
give reasons or explanations
thanks
below is from jacaranda:
Lenzs law states: an induced emf always gives rise to a current that creates a
magnetic filed that opposes the original change in flux through the circuit. Which
means that an current would be induced in the direction opposite to the cause.
The principal of energy states: energy cannot be created nor destroyed, but it can be transformed from one form to another.
If a changing flux in a coil would produce a magnetic flux in the same direction as the original change of flux, then it would lead to a greater change in flux threading the coil, which in turn would lead to an even greater change in flux, and the induced current would continue to increase. However this cannot occur, as if is happens, then we would be creating energy which violets the principle of conservation of energy.
but it doens't really answer the dot point, it doesn't say why it does not violet the conservation of energy...it just stops there saying that it cant....
give reasons or explanations
thanks