Explain the working of a magnetic crane.

A uniform magnetic field exists in the plane of paper pointing from left to right as shown in figure. In the field an electron and a proton move as shown. The electron and the proton experience.

In the below figure the direction of magnetic field at a point A above the current carrying conductor is

The strength of the magnetic field inside a long current-carrying straight solenoid is:   

If the key in the arrangement as shown below is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are:

A wire carries electric current from south to north. If it is placed in a magnetic field pointing towards the west, the force on it will be pointing vertically _____ (upwards/downwards).