What is the nature of the magnetic field lines inside a current-carrying solenoid?

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?

Why does a current-carrying conductor kept in a magnetic field experience a force? On what factors does the direction of this force depend? Name and state the rule used for the determination of the direction of this force.

The strength of the magnetic field of a solenoid does not depend upon:

Which is the direction of magnetic force acting on a current-carrying wire placed in a magnetic field?

In which of the following cases will maximum electric current be induced in the loop?