6. A transformer having 1000 primary turns is connected to a 250-V a.c. supply. For a secondary voltage of 400 V, the number of secondary turns should be :
(a) 1600
(b) 250
(c) 400
(d) 1250
7. The primary and secondary induced e.m.fs. E1 and E2 in a two-winding transformer are always :
(a) equal in magnitude
(b) antiphase with each other
(c) in-phase with each other
(d) determined by load on transformer secondary
8. If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is :
(a) 50 W
(b) 75 W
(c) 100 W
(d) nbsp;200 W
9. In performing the short circuit test of a transformer :
(a) high voltage side is usually short circuited
(b) low voltage side is usually short circuited
(c) any side is short circuited with preference
(d) none of the above
10. A transformer has negative voltage regulation when its load power factor is :
(a) zero
(b) unity
(c) leading
(d) lagging
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- Transformer » Exercise - 18. If the primary power of an ideal transformer having a 2:1 voltage ratio is 100 W, the secondary power is : (a) 50 W (b) 75 W (c) 100 W (d) 200 W
- Transformer » Exercise - 16. A transformer having 1000 primary turns is connected to a 250-V a.c. supply. For a secondary voltage of 400 V, the number of secondary turns should be : (a) 1600 (b) 250 (c) 400 (d) 1250
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