✔ 最佳答案
1. These are only different presentation of the same physical qunatity, the output power of the transformer.
The output voltage of a transformer is definitely known, hence given the ouptut current, the output power can be worked out. The direct giving of the current instead of power facilitates the estimation of charging time of batteries, which is ususally given in mAh.
2. Power = voltage x current = 7.5 x 150/1000 watts = 1.125 watts