MCQ for GATE,IES,PSU

1)In the transformer circuit mode,the core loss is represented by:-
a)shunt resistance
b)series resistance
c)shunt inductance
d)series inductance

2)Full load voltage regulation of a power transformer is zero when power factor of the load is near:-
a)unity and leading
b)zero and leading
c)zero and lagging
d)unity and lagging

3)The efficiency of two identical transformer under load condition can be determined by:-
a)back to back test
b)open circuit test
c)short circuit test
d)any of the above

4)The efficiency of a power transformer can be determined indirectly by:-
a)open circuit test alone
b)short circuit test alone
c)a&b
d)back to back test

5)The transformer efficiency will be maximum at a power factor of
a)0.8 lag
b)unity
c)0.8 lead
d)0.5 led or lag
Answer-
1)a,2)a,3)a,4)c,5)b