A. Telephones
B. Relays
C. Time switches
D. All of the above
Related Mcqs:
- Which of the following rectifiers have been used extensively in supplying direct current for electroplating ?
A. Copper oxide rectifiers
B. Selenium rectifiers
C. Mercury arc rectifiers
D. Mechanical rectifiers
E. None of the above - In which of the following appUcations, direct current is absolutely essential ?
A. Illumination
B. Electrolysis
C. Variable speed operation
D. Traction - Which of the following mercury arc rectifier will deliver least undulating current?
A. Six-phase
B. Three-phase
C. Two-phase
D. Single-phase - In a glass bulb mercury arc rectifier the maximum current rating is restricted to___________?
A. 2000 A
B. 1500 A
C. 1000 A
D. 500 A - Which of the following rectifiers are primarily used for charging of low voltage batteries from AC supply ?
A. Mechanical rectifiers
B. Copper oxide rectifiers
C. Selenium rectifiers
D. Electrolytic rectifiers
E. Mercury arc rectifiers - The metal rectifiers are preferred to valve rectifiers due to which of the following advantages ?
A. They are mechanically strong
B. They do not require any voltage for filament heating
C. Both (A) and (B)
D. None of the above - Which of the following statement is incorrect ?
A. Copper oxide rectifier is a linear device
B. Copper oxide rectifier is not a perfect rectifier
C. Copper oxide rectifier has a low efficiency
D. Copper oxide rectifier finds use in control circuits
E. Copper oxide rectifier is not stable during early life - Normally, which of the following is used, when a large-scale conversion from AC. to D.C. power is required ?
A. Motor-generator set
B. Motor converter
C. Rotary converter
D. Mercury arc rectifier - Which of the following metals is generally manufactured by electrolysis process ?
A. Load
B. Aluminium
C. Copper
D. Zinc
E. None of the above - Which of the following are the applications of D.C. system ?
A. Battery charging work
B. Arc welding
C. Electrolytic and electro-chemical processes
D. Arc lamps for search lights
E. All of the above
