Question

What is the Lenz's law of rotation?

Answer 1

Lenz's Law of rotation is essentially an extension of **Lenz's Law**, which states that the direction of an induced current (or induced electromotive force, EMF) in a conductor is always such that it opposes the change in magnetic flux that caused it.

In the context of **rotation**, Lenz's Law works the same way but specifically applies to situations involving rotational motion and magnetic fields, like in electric motors or generators.

When a conductor (like a coil) moves through a magnetic field or when a magnetic field around a coil changes, an electric current is induced in the coil. According to Lenz's Law, this induced current will create its own magnetic field that **opposes the motion** or the change in the magnetic flux.

In the case of rotation:

1. **Rotating Conductors**: If a coil is rotating in a magnetic field, it cuts through the magnetic lines of force, inducing an EMF. The direction of this induced EMF creates a current that generates a magnetic field opposing the coil’s rotation.
  
2. **Opposition to Motion**: The opposing magnetic field tries to resist the change in motion. This is why, for example, when you try to rotate a motor's armature or a generator's rotor, you'll feel resistance. The rotation slows down because the system is working against the force that’s driving it.

So, in summary:
- **Lenz’s Law of Rotation** says that the induced current’s magnetic field will act to oppose the change in rotation or movement of the conductor within the magnetic field, which is essentially the *backward force* you feel when trying to rotate something in a magnetic field (like in motors or generators).

It’s all about **conservation of energy** — nature resists changes, and this law ensures that energy is not created or destroyed in the system.