1. Long overhead line is switched off
2. Bank of capacitors is switched off
3. Transformer on no load is switched off
4. Heavy load is switched off
Transformer on no load is switched off
1. Direct strokes of lighting
2. Power frequency of over voltages
3. Overvoltages due to indirect lightning stroke
4. Overcurrents due to lightning stroke
Overvoltages due to indirect lightning stroke
1. Second harmonic current
2. Third harmonic current
3. Fifth harmonic current
4. Seventh harmonic current
Fifth harmonic current
1. Produced of rated breaking current (kA) and rated voltage (kV)
2. Product of rated symmetrical breaking current (kA) and rated voltage (kV)
3. Product of breaking current (kA) and fault voltage (kV)
4. Twice the value of rated current (kA) and rated voltage (kV)
Produced of rated breaking current (kA) and rated voltage (kV)
1. Excitation control
2. Phase shifting transformer
3. Single pole switching of circuit breakers
4. Increasing the turbine valve opening
Excitation control
1. A and B
2. A and C
3. B and C
4. only at C
A and B
1. Maintain voltage at the rated voltage level
2. Maintain frequency exactly at 50 Hz
3. Maintain a spinning reserve margin at all times
4. Maintain synchronous between machines and on external tie lines
Maintain a spinning reserve margin at all times
1. Greater than that of hydro generator
2. Greater than that of turbo alternator
3. Equal to that of the effective length of the line
4. None of these
None of these
1. 2.6
2. 0.615
3. 1.625
4. 9.0
0.615
1. 47.5 Hz
2. 48.0 Hz
3. 48.5 Hz
4. 49.0 Hz
48.0 Hz