When is the force experienced by a current-carrying conductor placed in a magnetic field largest ?

A thick wire is hanging from a wooden table. An anticlockwise magnetic field is to be produced around the wire by passing current through this wire by using a battery. Which terminal of the battery should be connected to the:

(a) top end of wire?

(b) bottom end of wire?

What happens when a current-carrying conductor is placed in a magnetic field?

In a statement of Fleming's left-hand rule, what do the following represent?

(a) direction of centre finger.

(b) direction of forefinger.

(c) direction of thumb.

Name one device which works on the magnetic effect of current.