Few Transformers viva questions

Hi all,
           
                Please find  few viva questions from transformers.

1.     Define Transformer(T/F)

2. What happens if DC supply is given to transformer?

3. a) On which principle T/F Works.   b) What  is isolation T/F and what is its uses.

4. Why T/F is called constant flux device.

5.     Why T/F is called static piece of device.

6.     Why T/F is called constant power device.

7.     Why T/F is called constant frequency device.

8.     What is ideal and practical T/Fs?

9.     Define primary winding, secondary winding.

10.                        Define LV (Low Voltage) Wdg, HV Wdg.

11.                        What is the Relation between Emf/Turn in primary Wdg, Secondary Wdg?

12.                        Why primary Wdg, Secondary Wdg are interleaved (placed on same leg).

13.                        Why always LV Wdg is placed near by the core.

14.                        What is demagnetizing turns in T/F.

15.                        Define MMF

16.                        What are different types if loads

17.                        Define power factor.

18.                        Define active power, reactive power

19.                        How variation in load is connected to variation of power factor.

20.                        What is the use of I_w, I_m,

21.                        What R_o, X_o represents.

22.                         What is turns ratio? Write the value if K for step up, step down isolation T/Fs.

23.                        What is maximum efficiency condition in T/F.

24.                        Where hysteresis loss, eddy current loss occurs in T/F, WHY  they occur, how to minimize them..

25.                        Why Iron losses are called constant loss.

26.                        Why copper losses are called variable losses.

27.                        Why transformer is rated in KVA instead of KW.

28.                        A) Why we need to increase the voltage level

              B) Why need to decrease the voltage level.

29.                        In OC test on T/F what happens if input  supply is given HV Wdg and LV in open circuited.

b) In SC test on T/F what happens if supply is given to LV Wdg and HV winding is  short circuited.

30.  A) How to identify MI, MC instruments

    B) Differentiate MI, MC instruments.

31.   What is LPF wattmeter and UPF watt meter?

32.     (a)What OC test on Transformer gives?

(b) What SC test on transformer gives?

  33.(a) Watt meter reading in OC test Represents ___________

      (b) Watt meter reading in SC test represents____________

34. Define voltage regulation in transformer

35. When can voltage regulation of transformer becomes zero?

36. Type of EMF induced in transformer________

37.what are differences between core type T/f and shell T/f
38.What are power transformers and distribution transformers