Electrical Machines Questions and Answers_pag164

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Answer: a 
Explanation: As the relative speed will be zero in the damper winding and the torque too. 
18. Slip test is performed to obtain 
a) direct axis reactance and quadrature axis reactance 
b) slip 
c) positive and negative sequence reactance 
d) sub transient reactance 
View Answer 
Answer: a 
Explanation: Slip test is used to determine the direct axis and quadrature axis reactance. 
This set of Electrical Machines Multiple Choice Questions & Answers (MCQs) focuses on 
“Synchronous Machine Applications”. 
1. One of the most prominent component of base loads is 
a) synchronous generator 
b) induction generator 
c) dc series generator 
d) all of the mentioned 
View Answer 
Answer: a 
Explanation: Synchronous machines are the main generating section of the power plants. 
2. ______ alternator is used in thermal stations and ______ alternator is used in hydel plants. 
a) Cylindrical-rotor, salient pole 
b) Salinet pole, cylindrical-rotor 
c) Salient pole, Reluctance 
d) Cylindrical-rotor, cylindrical-rotor 
View Answer 
Answer: a 
Explanation: Due to salient poles, the machine will not run at very large speed and it becomes 
less rugged. 
3. Synchronous compensators are mainly employed for 
a) compensating reactive power 
b) compensating real power 
c) improving power factor 
d) compensating field flux 
View Answer 
Answer: a 
Explanation: Synchronous compensator is a source for the reactive power. 
4. We prefer induction motor over synchronous motor due to 
a) no requirement of dc supply 
b) starting problems 
c) sensitive to environment 
d) all of the mentioned 
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