Choose the incorrect statement.

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.

What constitutes the field of a magnet?

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

How can we find the direction of the magnetic field due to a straight current-carrying conductor?

Describe in short an activity to:
$(i)$ demonstrate the pattern of magnetic field lines around a straight current-carrying conductor, and
$(ii)$ find the direction of the magnetic field produced for a given direction of current in the conductor. Name and state the rule to find the direction of the magnetic field associated with a current-carrying conductor. Apply this rule to determine the direction of the magnetic field inside and outside a current-carrying circular loop lying horizontally on a table. Assume that the current through the loop is anticlockwise.