Question 1

Multi-layer helical windings are commonly used in the transformers as high voltage windings

Accepted Answer

A) upto 20 kV 
B) upto 50 kV 
C) upto 80 kV 
D) for 110 kV and above

Question 2

are always double layer type.

Accepted Answer

A) Closed windings 
B) Open windings 
C) Either of the above 
D) None of the above

Question 3

The cold rolled grain oriented steel has ______ permeability in the direction of the grain orientation.

Accepted Answer

A) minimum 
B) maximum 
C) nil 
D) none of the above

Question 4

For 275 kV transformers, using cold rolled grain oriented steel, which of the following values of flux density may be used?

Accepted Answer

A) 1.0 Wb/m2 
B) 1.1 Wb/m2 
C) 1.3 Wb/m2 
D) 1.6 Wb/m2

Question 5

D.C. windings are

Accepted Answer

A) sometimes 2-layer type 
B) never 2-layer type 
C) always 2-layer type 
D) none of the above

Exam 3: Transformer Design and Electromagnets

Multi-layer helical windings are commonly used in the transformers as high voltage windings