What is the coil-like structure made of insulated copper wire wound in a cylindrical shape called?

$A$ coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is pushed into the coil?

What is a solenoid? Explain with the help of a figure how a solenoid behaves like a bar magnet.

$A$ 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?

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

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