AC power in a load can be controlled by using_____________?
(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
The switching function of semiconductor devices can be characterized with____________?
(A) Duty ratio only
(B) Frequency only
(C) Duty ratio and frequency
(D) Duty ratio, frequency and time delay
Electrical power output in a D.C. generator is equal to_____________?
(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
If a shunt motor is started with its field winding open then___________?
(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
The power demand can be estimated approximately by____________?
(A) Load survey method
(B) Mathematical method
(C) Statistical method
(D) Economic parameters
Power electronics essentially deals with control of a.c. power at____________?
(A) Frequencies above 20 kHz
(B) Frequencies above 1000 kHz
(C) Frequencies less than 10 Hz
(D) 50 Hz frequency
In a series parallel circuit, any two resistances in the same current path must be in___________?
(A) series with each other
(B) parallel with each other
(C) series with the voltage source
(D) parallel with the voltage source
For high efficiency of transfer of power, internal resistance of the source should be____________?
(A) equal to the load resistance
(B) less than the load resistance
(C) more than the load resistance
(D) none of the above
Kirchhoff s law is not applicable to circuits with____________?
(A) lumped parameters
(B) passive elements
(C) distributed parameters
(D) non-linear resistances
Which of the following is non-linear circuit parameter?
(A) Inductance
(B) Condenser
(C) Wire wound resistor
(D) Transistor