Why there is an electric field only inside the resistor in the circuit (assuming that the wire has no resistance). If there is no electric field inside the wire, why does the electron move to the positive pole?

Many questions have been asked here about why the Earth has a magnetic field, e.g., What is the source of Earth's magnetic field? How does Earth's interior dynamo work? How can an electrically neutral planetary core be geodynamo? At the risk of oversimplifying a bit, the answer is the dynamo...

If we're thinking about a case where bar magnet is placed on a flat surface, with its N-pole on the right and a compass is placed just above the middle of the magnet, in which direction will the compass needle point? Will it go in circles? Here's a diagram:

Chaos is not a random process, although it may look like one. If I am given a set of observations, is it possible to determine if the observations are generated by a random process or if they are generated by a chaotic process? What properties or characteristics of the observations can be used to...

I learned the total angular momentum is conserved in a two-body system. But as far as I saw the descriptions of two-body problem on several textbooks, none of those mention the angular momentum of each body. My question is: is the angular momentum of each body a conserved quantity?

The effective mass is a tensor property of rank two. It may be anisotropic if the corresponding electron band is not perfectly isotropic. For Silicon, this seems to be the case. However, there exists an alternative approach, which describes tensors of physical significance for crystals based on t...