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 （）
A.1 volt, the output changes 5 volts B.5 volts, the output changes 1 volt C.5 volts, the output changes 10 volts D.10 volts, the output changes 5 volts
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 （）
单项选择题 When the voltage remains constant and the resistance is increased in a series circuit, the flow of current （）
