Selenium rectifier can be operated at temperatures as high as 25°C 75°C 40°C 60°C TRUE ANSWER : ? YOUR ANSWER : ?
The voltage drop at anode, in a mercury arc rectifier is due to energy spent in overcoming the electrostatic field high ionization potential self restoring property of mercury high temperature inside the rectifier TRUE ANSWER : ? YOUR ANSWER : ?
On which of the following factors the number of phases for which a rectifier should be designed depends? All of the listed here The voltage regulation of the rectifier should be low In the output circuit there should be no harmonics The power factor of the system should be high TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following AC. motors is usually used in large motor-generator sets? Synchronous motor Squirrel cage induction motor Any of the listed here Slip ring induction motor TRUE ANSWER : ? YOUR ANSWER : ?
The efficiency of an electrolytic rectifier is nearly 70 % 50 % 40 % 60 % TRUE ANSWER : ? YOUR ANSWER : ?
In a phase-shift control method, the phase shift between anode and grid voltages can be achieved by means of Synchronous motor Synchronous generator Induction regulator Shunt motor TRUE ANSWER : ? YOUR ANSWER : ?
In a three-phase mercury arc rectifiers each anode conducts for One-fourth of a cycle One-third of a cycle One-half a cycle Two-third of a cycle TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following mercury arc rectifier will deliver least undulating current? Six-phase Single-phase Two-phase Three-phase TRUE ANSWER : ? YOUR ANSWER : ?
In a mercury arc rectifier positive ions are attracted towards anode mercury pool cathode shell bottom TRUE ANSWER : ? YOUR ANSWER : ?
In phase-shift control method the control is carried out by varying the of grid voltage. All of the listed here polarity magnitude phase TRUE ANSWER : ? YOUR ANSWER : ?