Question: While conducting short-circuit test on a transformer the following side is short circuited?

• 1. High voltage side
• 2. Low voltage side
• 3. Primary side
• 4. Secondary side

Question: Which of the following is not a part of transformer installation ?

• 1. Conservator
• 2. Breather
• 3. Buchholz relay
• 4. Exciter

Question: The purpose of providing an iron core in a transformer is to_____________?

• 1. provide support to windings
• 2. reduce hysteresis loss
• 3. decrease the reluctance of the magnetic path
• 4. reduce eddy current losses

Question: No-load current in a transformer________________?

• 1. lags behind the voltage by about 75°
• 2. leads the voltage by about 75°
• 3. lags behind the voltage by about 15°
• 4. leads the voltage by about 15°

Question: The efficiency of a transformer will be maximum when_____________?

• 1. copper losses = hysteresis losses
• 2. hysteresis losses = eddy current losses
• 3. eddy current losses = copper losses
• 4. copper losses = iron losses

Question: The permissible flux density in case of cold rolled grain oriented steel is around__________?

• 1. 1.7 Wb/m2
• 2. 2.7 Wb/m2
• 3. 3.7 Wb/m2
• 4. 4.7 Wb/m2

Question: Sumpner’s test is conducted on transformers to determine_____________?

• 1. temperature
• 2. stray losses
• 3. all-day efficiency
• 4. none of the above

Question: The dielectric strength of transformer oil is expected to be______________?

• 1. lkV
• 2. 33 kV
• 3. 100 kV
• 4. 330 kV

Question: No-load on a transformer is carried out to determine______________?

• 1. copper loss
• 2. magnetising current
• 3. magnetising current and loss
• 4. efficiency of the transformer

Question: The path of a magnetic flux in a transformer should have______________?

• 1. high resistance
• 2. high reluctance
• 3. low resistance
• 4. low reluctance