1、Despite this variation in complexity and cost however, they all have one factor in common and that is their need for electrical energy. 译文：不论这些诊断成像设备的复杂性和价值有何不同，它们都有一个共同的特点，那就是它们都需要不同形式的电能。 2 、Such an energy conversion takes place in the power station, the heat energy released by burning coal or oil being used to boil water and produce steam, which under pressure acts on the blades of a turbine causing it and the rotor to rotate. 译文：电站所完成的就是（以下的）这种转换：用烧煤或油得到的热量烧水，其产生的蒸汽以一定的压力作用于涡轮机的叶片，使叶片和转子旋转。 3 、To maintain the speed of rotation of the turbine more energy is needed to turn it and this extra energy is provided by burning more coal or oil and therefore increasing the pressure of the steam which drives the turbine. 译文：为了保持涡轮机的旋转速度就需要更多的能量来驱动它，也就是说要消耗更多的煤或油来产生驱动涡轮机的蒸汽。 4 、The electrical energy used by the consumer can never exceed the energy used by the power station and indeed will always be less as some energy is used in overcoming friction etc. in the turbine. 译文：电站以电能形式提供给用户的能量绝对不可能多于电站本身所消耗的能量，因为这其中还有一部分能量用来克服涡轮机本身的摩擦等阻力。 5 、Each e.m.f. is stepped up at the power station to approximately 400kV by the use of h.t. ( high tension) transformers and transmitted to consumers throughout the country via overhead transmission lines. 每个电动势在电站中由高压变压器升压到接近 400kV，然后由高压线路传送到全国各地。 6 、Each electrical component is rated in terms of the maximum current it can safely carry and the maximum voltage it can withstand. 一般的电器元件都有额定电流或额定电压，也就是元件所能承受的工作电流或电压的最大值。 7 、...
