MGVCL Exam Paper (30-07-2021 Shift 1)
Three resistances 750 Ω, 600 Ω and 200 Ω are connected in parallel. The total current is 1 A. Determine the voltage applied.
Bus Type - Known Parameter - Unknown Parameter Load Bus -P, Q - V, phase angle Generator Bus - P, V (magnitude) - Q, Voltage phase angle Slack Bus Voltage - magnitude and phase angle - P, Q
The methods often employed in practice to improve system stability are: 1. Increasing System Voltage 2. Reduction in Transfer Reactance 3. Using High Speed Circuit Breaker 4. Automatic Reclosing 5. Transient Stability 6. Turbine Fast Valving 7. Application of Braking Resistors 8. Single Pole Switching:
Carrier current over the power line provides simultaneous tripping of circuit breakers at both ends of the line in one to three cycles. Thereby high-speed fault clearing is obtained, which improves the power system stability. The auto-reclosing simultaneous reclosing signal is sent thereby simultaneous (1 to 3 cycles) reclosing of the circuit breaker is obtained. For simultaneous faults, carrier-current protection provides easy discrimination.
As per answer key "pilot protection" is true but there is mistake the right answer is "none".
Thermistors are ideal when measuring a single point temperature that is within 50°C of ambient. If the temperatures are excessively high or low, a thermistor will not work. Most thermistors work best in the range between -55°C and +114°C. Sensitivity of thermistor is high. Span value of thermistor is low.
EXAMIANS