Practice Test: Question Set - 01
1. Which of the following is an advantage of hydrogen cooling?
- (A) Increase in efficiency
- (B) Increase in ratings
- (C) Increase in life
- (D) All of the above
2. ________ cooling is the process of dissipating the armature and field winding losses to a cooling medium circulating within the winding insulation wall
- (A) Direct
- (B) Indirect
- (C) Conventional
- (D) Any of the above
3. _________ electromagnets generally function as holding magnets.
- (A) Tractive
- (B) Portative
- (C) Either of the above
- (D) None of the above
4. Direct water cooling of rotor winding presents
- (A) No mechanical difficulties
- (B) Lesser mechanical difficulties
- (C) Greater mechanical difficulties
- (D) None of the above
5. The winding where dummy coils are used is sometimes called
- (A) Duplex winding
- (B) Triplex winding
- (C) Forced winding
- (D) None of the above
6. The heat dissipating capability of transformers of ratings higher than 30 kVA in increased by providing which of the following?
- (A) Corrugations
- (B) Fins
- (C) Tubes
- (D) All of the above
7. A current density of _________ is used for large power transformers with forced circulation of oil or with water cooling coils
- (A) 1.5 to 2.5 A/mm2
- (B) 3.5 to 4.5 A/mm2
- (C) 4.0 to 5.0 A/mm2
- (D) 5.4 to 6.2 A/mm2
8. D.C. servomotors are used in
- (A) Purely D.C. control systems
- (B) Purely AC. control systems
- (C) Both D.C. and AC. control systems
- (D) None of the above
9. In a D.C. machine the current per brush arm should not be more than
- (A) 100 A
- (B) 200 A
- (C) 300 A
- (D) 400 A
10. Which of the following methods may be adopted to reduce the effects of armature reaction?
- (A) Increase in length of air gap at pole tips
- (B) Increasing reluctance of pole tips
- (C) Compensating windings
- (D) All of the above
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