【单选题】Multiple selection problem (one option) For the circuit, if the frequency of the excitation is f=100Hz, it is( ); if the frequency of the excitation is f=200Hz.
【多选题】When two tuning forks are sounded at the same time, a beat frequency of 5 Hz occurs. If one of the tuning forks has a frequency of 245 Hz,the frequency of the other tuning fork is .
【简答题】Multiple selection problem (one option) For of the capacitors, if the frequency of the terminal voltage is 50Hz, the frequency of its absorbed instantaneous power is: