Use of auto-transformer is economical when the transformation ratio is?

Use of auto-transformer is economical when the transformation ratio is?

Use of auto-transformer is economical when the transformation ratio is near unity.

Related

Description : Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is?

Answer : Auto-transformer makes effective saving on copper and copper losses, when its transformation ratio is approximately equal to 1.

Description : The voltage transformation ratio of a transformer is equal to the ratio of?

Answer : The voltage transformation ratio of a transformer is equal to the ratio of secondary induced e.m.f. to primary induced e.m.f.

Description : Define: 1) voltage ratio, 2) current ratio, 3) transformation ratio of transformer.

Answer : 1) Voltage ratio: The voltages in primary and secondary winding is proportional to number of turns in primary and secondary respectively. So, the voltage ratio is same as transformation ratio. V2/V1 = N2 ... as transformation ratio of transformer. It is denoted by K. K = N2/N1

Description : What is transformation ratio?

Answer : Transformation Ratio (k):- It is the ratio of secondary number of turns to primary number of turns. OR It is the ratio of secondary voltage to primary voltage. OR It is the ratio of primary current to secondary current.

Description : An Auto-transformer (which has only one winding) may be used as a ______ .  (A) Both Step-Up and Step-Down transformer (B) Step-Down Transformer (C) Step-Up Transformer (D) None of these

Answer : an autotransformer may used only as step down transformer