The direction of the magnetic field produced by a current-carrying straight wire depends on which of the following?

In the below figure,$A$ and $B$ represent two straight wires carrying equal currents in a direction at right angles to the plane of paper inwards. Sketch separately the magnetic field lines produced by each current. Give a reason why the magnetic field at $K$ (mid-point of the line joining $A$ and $B$) will be zero.
What will be the effect on the magnetic field at $K$ if the current in wire $B$ is reversed?

For the circular coil carrying current shown alongside,draw magnetic field lines. Decide which of its face behaves as north pole and which face as south pole. Give reason to justify your answer.

By placing an iron-like metal inside the solenoid,its magnetic field becomes $......$

Which of the following correctly describes the magnetic field near a long straight wire?

What is a solenoid? Explain with the help of a figure how a solenoid behaves like a bar magnet.