Write a comparison of the current in three bulbs of increasing resistance connected in a series arrangement.

In a series arrangement, the current is the same everywhere in the circuit. If 3 bulbs are in series, the current is the same through each bulb.

It says this right there at the beginning of the 2nd paragraph.

the minimum amperage that the current in this wire would have to have so that its weight is completely supported by the magnetic force due to earth's field, assuming that no other forces except gravity act on it