单项选择题
A.opposes any change in the applied voltage
B.opposes any change in the current flow through the circuit
C.aids any changes in the applied voltage
D.aids any changes in the current through the circuit
单项选择题 The operator of electrical motors should keep a constant check on the loads they carry because （）
单项选择题 Which of the listed sections of an emergency switchboard is used to supply power for alarm signals under emergency conditions?（）
单项选择题 When the current in a power transmission line is increased, the power loss （）