Lenz’s law is totally dependent on Newton’s third law of motion and the principle of conservation of energy. By using this law, we can easily calculate the direction of the induced current. According to Lenz’s law, the polarity of induced emf tends to produce a current that resists the magnetic flux transition that originated it.
If ΔΦ is the change in the magnetic flux, Δt is the change in time, emf is the induced voltage (electromotive force) and N is the number of loops, then, the expression is,
This formula’s negative sign describes the effect. The negative sign indicates that the direction of the induced emf and the change in magnetic field order have opposing signs. Lenz’s law applications are abundant. It can be utilised in eddy current dynamometers, eddy current balances, metal detectors, braking systems on the train, card readers, AC generators, microphones, etc.
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Important Questions with Answers
1. Is Lenz’s law the same as Faraday’s law?
No. Lenz’s law is concerned with energy conservation in electromagnetic induction, whereas Faraday’s law is concerned with the electromagnetic force produced. While Faraday’s law indicates the amount of the emf, Lenz’s law suggests the direction in which the current will travel. It states that the order is always such that it opposes the flux change that caused it.
2. What is Lenz’s law?
According to Lenz’s law, the generated electromotive force with distinct polarities causes a current via the loop, whose magnetic field resists the difference in magnetic flux to confirm that the actual flux is kept when the current flows.
3. What are the applications of Lenz’s law?
Lenz’s law has several applications, including understanding the concept of stored magnetic energy in an inductor. When an emf source is connected across an inductor, a current flows through it. The back emf will oppose this rise in current through the inductor. Lenz’s law applications are abundant. It can be utilised in eddy current dynamometers, eddy current balances, metal detectors, braking systems on the train, card readers, AC generators, microphones, etc.
4.Why is Lenz’s law of energy conservation accurate?
The law of conservation of energy leads to Lenz’s law. According to the law, energy cannot be destroyed or created; but it can only be transferred from one form to another. According to Lenz’s law, the current direction is such that it resists the change in magnetic flux.
5.What happens if Lenz’s law is reversed?
If Lenz’s law were precisely the opposite, the induced current would produce flux in the same direction as the original change. This more significant change in flux would have a larger current, followed by a more substantial change in flux, and so on.
6.What are the limitations of Lenz’s law?
When the magnet moves through the coil or other face, the current flow changes direction and the inside magnetic field is enhanced in the same direction due to the exterior magnetic field, thus opposing the change.
7.How does Lenz’s law affect generators?
Lenz’s law represents the direction of generated voltage due to current flow around a loop. Here, the voltage pushes the current in the order that opposes the difference in magnetic flux around the loop.
8.How does Lenz law determine direction?
According to Lenz’s law, the direction of the induced magnetic field will be in an order that opposes any change in flux. We can apply Fleming’s right-hand rule, which shows the direction of the magnetic field, to discover the direction of the induced current by indicating the thumb in that direction.
9. What is electromotive force?
Electromotive force is the electric potential created by adjusting the magnetic field or using an electrochemical cell. Here, emf is an abbreviation for electromotive force.
A generator/battery can convert energy from one form to another. The first terminal becomes positively charged in these instruments, while the second becomes negatively charged. As a result, an electromotive force is described as work done on a unit of electric charge.
10. Describe Faraday’s first law of electromagnetic induction
Faraday’s and Henry’s extensive experiments applied the groundwork for finding and understanding electromagnetic induction. Faraday concluded from his experimental findings that an emf is produced when the magnetic flux across the coil changes over time. Consequently, Faraday’s first law of electromagnetic induction asserts that an electromotive force is induced whenever a conductor is placed in a fluctuating magnetic field. When the conductor circuit is closed, a current, called an induced current, is generated.
Practice Questions
- Write the expression of Lenz’s law.
- Explain Lenz’s law with the help of all experiments.
- How does Lenz’s law determine direction?
- State and explain Faraday’s second law of electromagnetic induction.
- How does Lenz’s law use the right-hand rule?
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