Question

Write Lenz's law?

Answer 1

Hint: In the given question we have to write the Lenz’s law and this law states that the direction of any electric current which is induced by a conductor by a changing magnetic field is such that the magnetic field created by the induced current opposes changes in the initial magnetic field.

Complete step-by-step solution:
Lenz’s law, in electromagnetism, states that an induced electric current flows in a direction such that the current opposes the change that induced it. This Lenz law was given in 1834 by the Russian physicist Heinrich Friedrich Emil Lenz (1804–65).
Let us discuss what is Lenz’s law so, the Lenz’s law states that-
The induced electromotive force with different polarities induces an electric current whose magnetic field opposes the change in the magnetic flux through the loop in order to ensure that the original flux is maintained through the loop when current flows through it.
This law is named after Emil Lenz and Lenz’s law depends on the principle of conservation of energy, that is energy can neither be created nor be destroyed and Newton’s third law that is every action has an equal and opposite reaction. It is the most convenient method to determine the direction of the induced current in the field. It states that the direction of an induced current is always such that it is to oppose the change in the circuit or the magnetic field that produces the electric current.
The expression for Lenz’s law is –
\[Emf=-N(\dfrac{\Delta \phi }{\Delta t})\]
This law is reflected in the form of Faraday’s law where the negative sign in the expression contributes towards Lenz law.
In the above given expression of Lenz’s law
\[Emf\]is the induced voltage which is also known as electromotive force.
\[N\] is the number of loops in the magnetic field
\[\Delta \phi \] is the change in magnetic flux
\[\Delta t\]is the change in time.

Note: The example for Lenz's law is that magnetic fields from strong magnets can form the counter-rotating currents in a copper or aluminum pipe. This can be shown by dropping the magnet through any copper or aluminium pipe. The descent of the magnet inside the pipe is observably slower than that when dropped outside the pipe.