What does the tangent to a magnetic field line show?

What does closer spacing of magnetic field lines represent?

Can magnetic field lines cross? Explain briefly.

Outside a bar magnet, which way do magnetic field lines point?

Inside a bar magnet, which way do magnetic field lines continue?

Why do magnetic field lines form closed loops?

What does a uniform magnetic field look like in a field-line diagram?

A compass is placed at a point where field lines curve. How does the compass align?

Why are magnetic field lines a representation rather than physical objects?

Do charged particles always move along magnetic field lines? Explain.

How can field-line density be related qualitatively to magnetic flux?

Why are field lines most crowded near the poles of a bar magnet?

How do magnetic field lines differ from electrostatic field lines around isolated charges?

A diagram shows field lines entering a region more densely than they leave. Why should that not represent a valid magnetic field through a closed boundary?

What mistake is made by saying field lines point where the force on a positive charge points?

A field-line diagram has equally spaced circular lines around a long straight current. What does the circular shape communicate?

Can a magnetic field line simply stop in empty space? Explain using flux.

Why can field-line diagrams show relative strength but not an exact field magnitude unless calibrated?

A compass needle points west at a location. What can you infer about the magnetic field there?

Explain how field-line diagrams encode the two facts \(\vec B\) has direction and \(\nabla\cdot\vec B=0\).