【简答题】The circuit is in steady-state, when ,the switch is closed. When , , .
【单选题】The resonant angular frequency for a series RLC circuit is , when , the circuit is:
【单选题】The circuit is in steady-state, when , the switch is opened. Then is:
【单选题】A positive edge-triggered J-K flip-flop is used to produce a two-phase clock. However, when the circuit is operated it produces erratic results. Close examination with an oscilloscope reveals the pres...
A.
A race condition exists between the Q and Q outputs to the AND gate.
B.
A race condition exists between the CLOCK and the outputs of the flip-flop feeding the AND gate.
C.
The PRESET and CLEAR terminals may have been left floating.
D.
A race condition exists between the J and K inputs.
【简答题】若 ,则向量 的夹角为________.
【简答题】若向量 与 的夹角为120° ,且 ,则 与 的夹角 为 .