MGVCL Exam Paper (30-07-2021 Shift 1)
Consider the following two statements and choose the correct answer. Statement 1: The V-curves of a synchronous motor show relationship between armature current and supply voltage. Statement 2: The plot of power factor against the field current of synchronous motor is known as inverted V curves.
The V-curves of a synchronous motor show relationship between Armature current (Ia) and Excitation current (If). The Inverted V-curves of a synchronous motor show relationship between power factor (pf) and field excitation (If).
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.
For small turbine starts generating power 12.6 kph (3.5 m/s) is the typical cut-in speed. At 36–54 kph (10–15 m/s) produces maximum generation power. At 90 kph (25 m/s) maximum, the turbine is stopped or braked.
The series electromagnet is energized by a coil known as current coil which is connected in series with the load so that it carry the load current. The flux produced by this magnet is proportional to and in phase with the load current.
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