The magnetic field produced by a current flowing through a straight conductor is inversely proportional to the $........$.

Write any one method to induce current in a coil.

$A$ straight conductor passes vertically through a cardboard sprinkled with iron filings. Show the setting of iron filings when a weak current is passed in the downward direction and then the cardboard is gently tapped. Draw arrows to represent the direction of magnetic field lines.
What changes occur if,
$(i)$ the strength of current is increased?
$(ii)$ the single conductor is replaced by several parallel conductors each carrying same current flowing in the same direction?

The figure below shows a current-carrying loop passing through a sheet of cardboard. Draw three magnetic field lines on the cardboard.
Give two factors on which the magnitude of the magnetic field at the centre of the loop depends.

With the help of a neat diagram,describe how you can generate induced current in a circuit.

If a circular loop is made of $6$ closely wound turns instead of a single turn,the magnetic field produced at the center of the loop becomes $.........$ times stronger.