At 0°C, frozen water (ice) changes to liquid water. When an ice cube is placed on something that is warmer than it heat will move from the warmer substance to the water until

a common temperature is reached.

Explanation:

The principle of heat transfer is that heat flows from a substance of higher temperature to that of lower temperature until when a common temperature is reached.

For ice on getting in contact with a hot body; it changes to water at 0°c utilising the latent heat of fusion. After ice has been converted to water at 0°c, water starts increasing in temperature till a common temperature is reached.

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