SI unit of magnetic field is

Which of the following is NOT correct for magnetic filed lines?

A constant current I flows in a horizontal wire in the plane of the paper from West to East as shown in the figure. The direction of magnetic field at a point will be South to North

The diagram shows a current carrying wire passing through the centre of a square card board. The magnetic field at points $A$, $B$  and $C$ is:

Observe the diagram.

The magnetic poles represented by P and Q respectively are

A bar magnet is used to pick up an iron nail

At which part P, Q, and R is the easiest for the magnet to pick up the iron nail? 

Observe the following diagram and choose the correct alternative.

The figure shows the magnetic field lines of a magnetic field. There are three points $A$, $B$ and $C$ in this field. Choose the correct option regarding field strength.

In figure, magnetic field between two magnets is shown. Which magnetic poles are present at point A and point B respectively of magnets?