The magnetic field produced by a current in a straight wire has no poles.

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.

$A$ magnetic compass shows a deflection when placed near a current-carrying wire. How will the deflection of the compass be affected if the current in the wire is increased? Support your answer with a reason.

$(a)$ Describe an experiment with a diagram to show that force is exerted on a current-carrying conductor when placed perpendicular in a magnetic field.
$(b)$ How will this force change if the current in the conductor is increased?
$(c)$ Name a device that uses the above principle.

Earthing of electrical appliances is very important.

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