TRANSFORMERS MCQs SET 20

TRANSFORMERS MCQs SET 20

1. Two-winding transformer of a given VA rating if connected as an autotransformer can handle ___________
a) Higher VA
b) Lower VA
c) Same VA
d) Cannot be found
 

Answer: a

2. When auto-transformation ratio becomes equal to 1, which of the following statement is true?
a) VA rating of the autotransformer becomes far greater than VA rating of two winding transformer
b) VA rating of the autotransformer becomes far lower than VA rating of two winding transformer
c) VA rating of the autotransformer becomes equal to VA rating of two winding transformer
d) Can’t comment
 

Answer: a

3. An autotransformer compared to its two-winding counterpart has a higher operating efficiency.
a) True
b) False
 

Answer: a

4. Ratio of winding material needed for autotransformer to thr two winding transformer is ______
a) 1- V2/V1
b) 1- N2/N1
c) 1- V2/V1 and 1- N2/N1
d) 1- V1/V2
 

Answer: c
5. For an auto-transformation ratio tending to the unity value, saving of the conductor material will be ___________
a) Tend towards 90% or more
b) Tend towards 0%
c) Can’t say
d) Wil remain fix
 

Answer: a

6. What are the modes in which power can be transferred in an autotransformer?
a) Conduction
b) Induction
c) Conduction and Induction
d) Cannot be said
 

Answer: c
7. A 100/10, 50 VA double winding transformer is converted to 100/110 V auto transformer. tWhat will be the rating of auto transformer?
a) 500 VA
b) 550 VA
c) 100 VA
d) 110 VA
 

Answer: b
8. For a 20kVA transformer with turn ratio 0.4 what amount of total power is transferred inductively?
a) 8kVA
b) 12kVA
c) 10kVA
d) 50kVA
 

Answer: b
9. For a 20kVA transformer with turn ratio 0.4 what amount of total power is transferred conductively?
a) 8kVA
b) 12kVA
c) 10kVA
d) 50kVA
 

Answer: a

10. Output transformers are also called for __________
a) Maximum efficiency
b) Maximum power
c) Maximum output
d) Maximum efficiency, power and output
 

Answer: b