The list of choices submitted with the question contains
no correct description of magnetic field lines.
The shape of the magnetic field around a long straight current-carrying wire is generally described as concentric circles perpendicular to the wire.
The list of choices submitted with the question containsno correct description of magnetic field lines.
Shielding
"Magnetic flux density" is also known as the magnetic field,The SI unit for this is the Tesla, written as T.CommentMagnetic flux density is not "also known as the magnetic field". It describes the intensity of a magnetic field.
When the current is reverted, the magnetic field will also be reverted.
The space surrounding a magnet in which the magnetic force acts is called a magnetic field. The magnetic field is the region where magnetic forces are generated and can influence other magnetic materials or moving charges.
Place the magnet vertically on the equator, with the north end facing the North Pole.
The magnetic force exerted in the region around a magnet is called a magnetic field. It is a vector field that describes the magnetic influence of the magnet on other objects or moving charges.
magnetic field is a imaginary area around a manetic material where other magnetic subestences experience some force but flux is the imaginary lines of force that arise from magnet which indicate direction of force around it.
Magnetic fields are produced because of moving electric charges, and visualizing the very complex mathematical relationships that fall under the magnetic field might become much easier if magnetic field lines were used. A higher density of field lines means a stronger magnetic field. Keep in mind that those lines do not actually exist; they are drawn only to visualize the strength of the magnetic field.
moving a loop of wire through a magnetic Field. The rotation of a coil of copper wire trough a magnetic field changes magnetic field as "seen" from the coil inducing an alternating current.
APEX: Field lines that are close together indicate a stronger magnetic field. They don't affect the magnet that created them. They never cross. They begin on north poles and end on south poles.