Single Phase Transformer

An ideal tx characteristics

• 100% inefficient

• less leakage flux

• zero copper losses

Type of losses except..

• eddy current

• hysterisis

• dielectric

If the primary coil of a transformer has 200 turns and the secondary coil has 400 turns, what is the turns ratio?

• 2

• 0.5

• 20

Open circuit test is used to determine the parameter of ??

• Req & jXeq

  &

  Rc & jXm

• Req & jXeq

• Rc & jXm

In a step-up transformer, the tx ratio is....

• less than 1

• greater than 1

• equal to 1

this figure shows phasor diagram of...

• lagging pf

• leading pf

• unity pf

10 kVA, 2500/250 A, find primary current

• 40 A

• 4 A

• 10 A

What are the two main parts of a transformer construction?

• The two main parts of a transformer construction are the primary winding and the secondary winding.

• The main parts of a transformer construction are the input and the output

• The main parts of a transformer construction are the battery and the switch

Given, 10/2 kV single phase tx with parameters:
R1 = 2 Ω X1 = 5 Ω

R2 = 0.5 Ω X2 = 0.1 Ω

Rc = 10 kΩ Xm = 5 kΩ

determine Req for an approximate eq. cct as referred to HV side

• 14.5 Ω

• 2.02 Ω

• 2.5 Ω

How is transformer efficiency calculated?

• Efficiency = (Output Power / Input Power) * 100

• Efficiency = (Output Power + Input Power) * 100

• Efficiency = (Input Power / Output Power) * 100