Question: The no-load current drawn by transformer is usually what per cent of the full-load current ?

• 1. 0.2 to 0.5 per cent
• 2. 2 to 5 per cent
• 3. 12 to 15 per cent
• 4. 20 to 30 per cent

Question: The degree of mechanical vibrations produced by the laminations of a transformer depends on____________?

• 1. tightness of clamping
• 2. gauge of laminations
• 3. size of laminations
• 4. all of the above

Question: A transformer core is laminated to__________?

• 1. reduce hysteresis loss
• 2. reduce eddy current losses
• 3. reduce copper losses
• 4. reduce all above losses

Question: In a transformer the energy is conveyed from primary to secondary_________?

• 1. through cooling coil
• 2. through air
• 3. by the flux
• 4. none of the above

Question: Which of the following does not change in a transformer ?

• 1. Current
• 2. Voltage
• 3. Frequency
• 4. All of the above

Question: When the interconnector between two stations has large reactance?

• 1. the transfer of power will take place with voltage fluctuation and noise
• 2. the transfer of power will take place with least loss
• 3. the stations will fall out of step be¬cause of large angular displacement between the stations
• 4. none of the above

Question: In the analysis of which of the following lines shunt capacitance is neglected?

• 1. Short transmission lines
• 2. Medium transmission lines
• 3. Long transmission lines
• 4. Medium as well as long transmission lines

Question: For transmission of power over a distance of 500 km, the transmission voltage should be in the range?

• 1. 150 to 220 kV
• 2. 100 to 120 kV
• 3. 60 to 100 kV
• 4. 20 to 50 kV

Question: The effect of corona can be detected by___________?

• 1. presence of ozone detected by odour
• 2. hissing sound
• 3. faint luminous glow of bluish colour
• 4. all of the above

Question: On which of the following factors skin effect depends?

• 1. Frequency of the current
• 2. Size of the conductor
• 3. Resistivity of the conductor material
• 4. All of the above