Which of the following statements are true concerning the creation of magnetic fields?
check all that apply.
check all that apply.
a moving electric charge creates a magnetic field at all points in the surrounding region.
a single stationary electric charge creates a magnetic field at all points in the surrounding region.
an electric current in a conductor creates a magnetic field at all points in the surrounding region.
a permanent magnet creates a magnetic field at all points in the surrounding region.
a distribution of electric charges at rest creates a magnetic field at all points in the surrounding region.

A moving electric charge creates a magnetic field at all points in the surrounding region.

An electric current in a conductor creates a magnetic field at all points in the surrounding region.

A permanent magnet creates a magnetic field at all points in the surrounding region.

Explanation:

Magnetic field can be produced by:

- moving charges (i.e. a moving electron, or a current in a conductor)

- A magnet

The strength of the magnetic field produced by a current-carrying wire is

where

I is the current

r is the distance from the wire

As we see from the formula, the magnetic field is produced at all points in the surrounding region, because B becomes zero only when r becomes infinite. The same is true for the magnetic field created by a single moving charge or by a magnet.

The following choices instead are not correct:

- A single stationary electric charge creates a magnetic field at all points in the surrounding region.

- A distribution of electric charges at rest creates a magnetic field at all points in the surrounding region.

Because they involve the presence of stationary charges, and stationary charges do not produce magnetic fields.

friction

explanation:

they us to move forward and backwards