A. Lighting and heating control
B. On – line transformer tap changing
C. Soft starting
D. All of these
Related Mcqs:
- n a phase controlled 3 phase ac voltage controller, the harmonic present is__________?
A. 2nd
B. 3rd
C. 5th
D. 7th - A step up chopper has input voltage 110 V and output voltage 150 V. The value of duty cycle is_____?
A. 0.32
B. 0.67
C. 0.45
D. 0.27 - Under over voltage condition impedance offered by the voltage clamping device is__________?
A. low
B. High
C. moderate
D. infinity - Practical way of obtaining static voltage equalization in series connected SCRs is by the use of____________?
A. One resistor across the string
B. Resistors of the same value across each SCR
C. Resistors of different values across each SCR
D. One resistor in series with each SCR - If the gate voltage of an SCR is removed, then the_______________?
A. anode current decreases
B. anode current does not decrease at all
C. anode current increases
D. cathode current increases - As the breakdown voltage reached, the DIAC exhibits?
A. Negative resistance characteristics
B. Goes into avalanche condition
C. Voltage drop snaps back
D. All of these - The average value of the output voltage in a step – down dc chopper is given by__________?
A. V 0 = V s
B. V 0 = D V s
C. V 0 = V s / D
D. V 0 = V s / ( 1 – D ) - A capacitive load in voltage source inverters generates ________________?
A. Small current spikes and can be reduced by using an inductive filter
B. Large current spikes and can be increased by using an inductive filter
C. Small current spikes and can be increased by using an inductive filter
D. Large current spikes and can be reduced by using an inductive filter - In a three phase voltage source inverters____________?
A. Only amplitude of voltage is controllable
B. Only phase is controllable
C. Both amplitude and phase is controllable
D. Amplitude, phase and frequency of voltages should always be controllable - In a 3 phase half wave rectifier, when firing angle is less than 90 degree, then the average dc output voltage becomes__________________?
A. Positive
B. Negative
C. Zero
D. None of these
