transformer 10-20

11) Which winding in a transformer has more number of turns.
   a) low voltage winding
   b) high voltage winding
   c) primary winding
   d) secondary winding

ans b

12) The phase difference between primary and secondary voltage of a transformer is 
   a) zero
   b) 60 degree
   c) 90 degree
   d) 180 degree
ans d

13) The core of a transformer is laminated to reduce 
   a) copper loss
   b) iron loss
   c) eddy current loss
   d) hysteresis loss
ans c

14) The transformer will have maximum efficiency when
   a) copper loss is less
   b) iron loss less
   c) copper loss is equal to iron loss
   d) iron loss zero
ans c

15) Auto transformer is used because 
   a) it is simple in construction
   b) it has more efficiency
   c) saving in copper is more
   d) none
ans c

16) Rating of transformer is given in 
   a) KVA
   b) KW
   c) KVAR
   d) KWH
ans a

17) Transformer works on 
   a) a.c
   b) d.c
   c) both a.c and d.c
   d) none
ans a

18) The short circuit test on a transformer is used to determine 
   a) the iron loss at any load
   b) the copper loss at any load or full load
   c) the eddy current loss
   d) the hysteresis loss
ans b

19) Transformer is a 
   a) static device
   b) rotating device
   c) direct current device
   d) electrostatic device
ans a

20) The oil used in a transformer provides 
   a) cooling only
   b) insulation only
   c) both cooling and insulation
   d) lubrication only
ans c