TRANSFORMERS MCQs SET 18

TRANSFORMERS MCQs SET 18

1. In an actual transformer the iron loss remains practically constant from no load to full load because ___________
a) Value of transformation ratio remains constant
b) Permeability of transformer core remains constant
c) Core flux remains practically constant
d) Primary voltage remains constant
 

Answer: c

2. Negative voltage regulation indicates ___________
a) Capacitive loading only
b) Inductive loading only
c) Inductive or resistive loading
d) Cannot be determined
 

Answer: a
3. When will a transformer have regulation closer to zero?
a) On full-load
b) On overload
c) On leading power factor
d) On zero power factor
 

Answer: c
4. A good voltage regulation of a transformer indicates ______________
a) output voltage fluctuation from no load to full load is least
b) output voltage fluctuation with power factor is least
c) difference between primary and secondary voltage is least
d) difference between primary and secondary voltage is maximum
 

Answer: a

5. Which of the following acts as a protection against high voltage surges due to lightning and switching?
a) Horn gaps
b) Thermal overload relays
c) Breather
d) Conservator
 

Answer: a
6. Minimum voltage regulation occurs when the power factor of the load is ______________
a) Unity
b) Lagging
c) Leading
d) Zero
 

Answer: c
7. Voltage regulation of transformer is given by _____________
a) E2-V2/V2
b) E2-V2/E2
c) V2-E2/E2
d) V2-E2/V2
 

Answer: b

8. On which load power factor zero voltage regulation will be achieved?
a) 0
b) 1
c) Leading
d) Lagging
 

Answer: c

9. A transformer has resistance and reactance in per unit as 0.01 and 0.04 pu respectively. What will be its voltage regulation for 0.8 power factor lagging and leading?
a) 3.2% and 1.6%
b) 3.2% and -1.6%
c) 1.6% and -3.2%
d) Can’t be defined
 

Answer: b

10. At which power factor one will get maximum voltage regulation?
a) 0
b) 1
c) Leading
d) Lagging
 

Answer: d