Practice Test: Question Set - 05
1. The advantage of mercury arc rectifier is that
- (A) It is light in weight and occupies small
floor space
- (B) It has high efficiency
- (C) It has high overload capacity
- (D) All of the above
2. Which of the following metals is generally manufactured by electrolysis process?
- (A) Load
- (B) Aluminium
- (C) Copper
- (D) Zinc
3. A rotary converter combines the function of
- (A) An induction motor and a D.C. generator
- (B) A synchronous motor and a D.C. generator
- (C) A D.C. series motor and a D.C. generator
- (D) None of the above
4. Which of the following A.C. motors is usually used in large motor-generator sets?
- (A) Synchronous motor
- (B) Squirrel cage induction motor
- (C) Slip ring induction motor
- (D) Any of the above
5. The internal efficiency of a mercury arc rectifier depends on
- (A) Voltage only
- (B) Current only
- (C) Voltage and current
- (D) None of the above
6. In selenium rectifiers efficiencies ranging from ________ to ________ percent are attainable
- (A) 25, 35
- (B) 40, 50
- (C) 60, 70
- (D) 75, 85
7. In a single phase rotary converter the number of slip rings will be
- (A) Two
- (B) Three
- (C) Four
- (D) Six
8. In a mercury arc rectifier positive ions are attracted towards Cathode
- (A) True
- (B) False
9. The voltage drop at anode, in a mercury arc rectifier is due to
- (A) Self restoring property of mercury
- (B) High ionization potential
- (C) Energy spent in overcoming the electrostatic
field
- (D) High temperature inside the rectifier
10. Copper oxide rectifier is usually designed not to operate above
- (A) 10°C
- (B) 20°C
- (C) 30°C
- (D) 45°C