What is the shape of magnetic field lines around a straight current-carrying conductor?

When an electric current flows through a conducting wire,what is produced in the region around it?

To find the direction of the magnetic field around a current-carrying conductor,we use Fleming's left-hand rule.

$AB$ is a current-carrying conductor in the plane of the paper as shown in the figure. What are the directions of the magnetic fields produced by it at points $P$ and $Q$? Given $r_1 > r_2$, where will the strength of the magnetic field be larger?

$A$ student performs an experiment to study the magnetic effect of current around a current-carrying straight conductor with the help of a magnetic compass.
He reports that:
$(i)$ the degree of deflection of the magnetic compass increases when the compass is moved away from the conductor.
$(ii)$ the degree of deflection of the magnetic compass increases when the current through the conductor is increased.
Which of the above observations of the student appears to be wrong and why?

Draw a labelled circuit diagram of a simple electric motor and explain its working. In what way are these simple electric motors different from commercial motors?