单项选择题
When the current in a power transmission line is increased, the power loss （）
A.increases as the square of the current B.decreases as the square root of the current C.remains the same, as it is independent of current flow D.increases in direct proportion as the current
单项选择题 An operational amplifier, as used in todays consoles, may have a calculated gain of 5√This means that as the input changes by （）
单项选择题 Why is it desirable to operate paralleled AC generators at the same power factor?（）
单项选择题 An ammeter should be used to measure （）
