Electrical Transformers Test – 2

1. Which of the following statements are correct for an ideal transformer?

I. Voltages - inverse ratio
II. Current - direct ratio
III. Impedance - direct ratio squared
Iv. KVA - remains same

2. The voltage induced at the end of primary terminals of a two winding transformer consisting of N turns is?

3. Consider a 2-winding transformer as below. If the switch is kept open then the emf induced across the secondary having transformation ratio of '2' is?

4. Which of the following statements support the ideal transformer features?

I. Zero winding resistance
II. Constant permeability
III. Constant core losses

5. Which of the following statements support the ideal transformer features?

I. Zero winding resistance
II. Zero leakage flux
III. Negligible core losses

6. Which of the following statements support the ideal transformer features?

I. Variable winding reactance
II. Constant permeability
III. Constant core losses

7. Which of the following statements support the ideal transformer features?

I. Zero winding resistance
II. Constant permeability
III. Constant core losses
Iv. Zero leakage reactance

8. Which of the following statement is true?

I. Core flux in an ideal transformer remains constant.
II. Core flux is independent of the load current.

9. Which of the following assumptions about the transformer supports the fact that the instantaneous power input and output of a transformer is equal?

I. Zero winding resistance
II. Constant permeability
III. Constant core losses
Iv. Zero leakage reactance

10. Which of the following statements are incorrect for an ideal transformer?

I. Voltages - inverse ratio
II. Current - direct ratio
III. Impedance - direct ratio squared
Iv. Power - remains same

11. Which of the following statements support the ideal transformer features?

I. Zero winding resistance
II. Zero leakage flux
III. Constant core losses

12. Consider a 2-winding transformer as below. If the switch is open then the emf induced across the secondary having transformation ratio of 2 is?

13. Consider a 2-winding transformer as below. If the switch is open then the emf induced across the load 'Zl' having transformation ratio of 2 is?

14. If it is happened to place an inductive load to a two winding transformer, then the phasor diagram for such a loading will be?

15. Identify the phasor diagram for an ideal transformer at no load.

16. Which of the following statements are correct for an ideal transformer?

I. Voltages - Direct ratio
II. Current - Inverse ratio
III. Impedance - Direct ratio squared
Iv. Power - Remains same