On which principle does an electric bell work?

Which scientist discovered that an electric current can be produced using a magnetic field?

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.

Which rule is used to determine the direction of induced current in a circuit?

By increasing the number of turns $3$ times in a toroidal solenoid,the magnetic field:

The induced potential difference produced in a coil when a magnet is inserted into it does not depend upon: