Autotransformers

The tappings on the transformers is provided on

While comparing potential transformer to an auto transformer, a potential transformer transfers power _____

I. KVA rating : 1/(1-k)
II. Losses : (1-k)
III. Impedance drop = 1/(1-k)
Which of the above are correct for an auto transformer when compared to the identical rating two winding transformer?

Three transformers having identical dimensions but with core of iron, aluminium and wood are wound with same number of turns and have same supply. Then choose the order for eddy current losses.

A 1-phase tranformer has a leakage impedance of 1+ j4 Ω for primary and 3+ j11 Ω for secondary windings. This transformer has

The statements which support the points that auto transformers are disadvantageous as compared to 2-winding transformer
I. Weight of conductor reduces
II. Direct electrical contacts
III. Leakage reactance reduces
IV. Lower short-circuit current

When a transformer winding suffers a short circuit, then inter turns of the same winding experience ______ forces.

Maximum efficiency of a transformer for a constant load current , occurs at

Two tranformer having same voltage but different KVA are operating in parallel. For a good load sharing,

The statements which support the points that auto transformers are advantageous
I. Weight of conductor reduces
II. Direct electrical contacts
III. Leakage reactance reduces
IV. Lower short-circuit current

The statements which support the points that auto transformers are advantageous
I. Weight of conductor reduces
II. Ohmic losses reduces
III. Leakage reactance reduces
IV. Lower short-circuit current

Three transformers having identical dimensions but with core of iron, aluminium and wood are wound with same number of turns and have same supply. Then choose the order for hysteresis losses.

If a transformer is at no load , then it will act like

The voltage regulation of a transformer at full-load 0.8 p.f leading is -2%. Its voltage regulation at full load 0.8 p.f lagging

In a transformer, we place the tapping windings at the middle because

The voltage regulation of a transformer depends on its
(A)equivalent reactance (B) equivalent resistance
(C)load power factor (D)transformer size
(E) load current