So the strong magnetic pole is n pole;

(2) The stress analysis of the circular ring can be equivalent to a straight steel wire, and the vertical direction is as follows

Mg=F amp cos60 = BILcos60；;

Ring circumference l = 2πr = 0.8m；;

Substituting the above formula can get b = 25t.

Therefore, the magnetic induction intensity at the ring is 25T；;

(3) The descending process of the ring is governed by the law of conservation of energy.

mgh = I2Rt = I2ρlSt；

Substitute data ρ= 1.25× 10-4ω? m；

Therefore, the resistivity of superconducting ring is about 1.25× 10-4ω? m；

Answer: (1) The strong magnetic pole is N pole;

(2) The magnetic induction intensity at the ring is 25T；;

(3) The resistivity of superconducting ring is about 1.25× 10-4ω? Meter (short for meter))