For similar carrier and modulating signals, the line current used in CSI is_____________?
A. Identical to line voltage in a VSI
B. Identical to line current in VSI
C. Identical to phase voltage in VSI
D. Identical to phase voltage in CSI
A. Identical to line voltage in a VSI
B. Identical to line current in VSI
C. Identical to phase voltage in VSI
D. Identical to phase voltage in CSI
A. Dependent on the load current
B. Dependent on the voltage
C. Dependent on both the load current and load voltage behind the short circuit current
D. Independent on both the load current and load voltage
During the commutation period in 3 phase converter, overlap time is____________? Read More »
Power Electronics A. Suppressing emissions
B. Reducing the efficiency of the coupling path
C. Reducing the susceptibility of the receptor
D. All of these
The effects of EMI can be reduced by_____________? Read More »
Power Electronics A. silicon has large leakage current than germanium
B. silicon has small leakage current than germanium
C. silicon has small leakage voltage than germanium
D. silicon has large leakage voltage than germanium
An SCR is made up of silicon because_____________? Read More »
Power Electronics A. two SCR’s in parallel opposition
B. two SCR’s in series
C. three SCR’s in series
D. four SCR’s in series
AC power in a load can be controlled by using_____________? Read More »
Power Electronics A. Duty ratio only
B. Frequency only
C. Duty ratio and frequency
D. Duty ratio, frequency and time delay
The switching function of semiconductor devices can be characterized with____________? Read More »
Power Electronics A. Electrical power developed in armature – copper losses
B. Mechanical power input – iron and friction losses
C. Electrical power developed in armature – iron and copper losses
D. Mechanical power input – iron and friction losses – copper losses
Electrical power output in a D.C. generator is equal to_____________? Read More »
Power Electronics A. It will rotate at the same speed as that with its field winding closed
B. It will rotate at less speed as that with its field winding closed
C. It will rotate at dangerously high speed
D. None of these
If a shunt motor is started with its field winding open then___________? Read More »
Power Electronics A. Load survey method
B. Mathematical method
C. Statistical method
D. Economic parameters
The power demand can be estimated approximately by____________? Read More »
Power Electronics A. Frequencies above 20 kHz
B. Frequencies above 1000 kHz
C. Frequencies less than 10 Hz
D. 50 Hz frequency
Power electronics essentially deals with control of a.c. power at____________? Read More »
Power Electronics