On which principle does an electric motor work?

Who first observed that a current-carrying wire experiences a force when placed in a strong magnetic field?

It is established that an electric current through a metallic conductor produces a magnetic field around it. Is there a similar magnetic field produced around a thin beam of moving $(i)$ alpha particles,$(ii)$ neutrons? Justify your answer.

Draw magnetic field lines produced around a current-carrying straight conductor passing through a cardboard. How will the strength of the magnetic field change when the point where the magnetic field is to be determined is moved away from the straight wire carrying a constant current? Justify your answer.

An electron enters a uniform magnetic field at right angles to it as shown in the figure below. In which direction will this electron move? State the rule applied by you in finding the direction of motion of the electron.

Why is the metallic body of electrical devices connected to the earth wire?