OC and SC test Viva

Under OC test ____ winding is kept open

• High voltage (HV)
• Low voltage (LV)
• Both HV and LV
• None of the above

Under OC test all the meters are connected on low voltage side

• A) Low range of ammeter, volt and watt meters are sufficient
• B) Very low current on HV side
• C) Both A & B
• None of the above

Power required during the open circuit and short circuit test is

• losses incurring in the transformer
• executing the power requirements by measuring instruments
• power for the core losses only
• all of the mentioned

The open circuit test results in finding which of the following parameters<br />I. core losses<br />II. shunt branch parameters<br />III. turns ratio of transformer<br />

• I,II,III
• I,II
• II,III
• I,III

Which of the following are obtained from short-circuit test?<br />I. Ohmic losses at rated current<br />II. Equivalent resistance and leakage reactance<br />III. Core losses<br />IV. Voltage regulation<br />

• I,II,IV
• II,III
• I,II,IV
• II,III,IV

Which of the below estimations require results of both open circuit test and short circuit test?

• Efficiency
• Equivalent impedance of one side of the winding
• Voltage regulation for exact circuit
• All of the mentioned

To conduct the open circuit test, test is conducted on the

• L.V side
• H.V side
• primary
• secondary

To conduct the short circuit test, test is conducted on the

• L.V side
• H.V side
• primary
• secondary

A single phase transformer of 2kVA, 400/200 V has to undergo open circuit test. The instruments used are voltmeter and ammeter to be

• 230V, 10A
• 230V,5A
• 430V, 10A
• 430V,5A

A single phase transformer of 2kVA, 400/200 V has to undergo short circuit test. The instruments used are voltmeter and ammeter to be

• 250V, 10A
• 50V,5A
• 400V, 10A
• 400V,5A