DGVCL Exam Paper (11-12-2011) If the excitation of a synchronous generator fails, it acts as a Synchronous motor Induction motor Synchronous generator Induction generator Synchronous motor Induction motor Synchronous generator Induction generator ANSWER EXPLANATION DOWNLOAD EXAMIANS APP if excitation of synchronous generator fails, operate as induction motor
DGVCL Exam Paper (11-12-2011) In a series RLC circuit at resonance Current is minimum and power factor is unity Current is maximum and power factor is unity Current is maximum and power factor is 0.5 Current is minimum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is unity Current is maximum and power factor is 0.5 Current is minimum and power factor is 0.5 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Magnetizing inrush current Unbalanced protection Switching over voltages Lightning Magnetizing inrush current Unbalanced protection Switching over voltages Lightning ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Initial inrush of magnetizing currents have high component of even and odd harmonics.2nd - 63%3rd -26.8%4th- 5.1%5th- 4.1%6th- 3.77th-2.4
DGVCL Exam Paper (11-12-2011) The form factor in AC means the ration of R.M.S. value to peak value Peak value to average value R.M.S. value to average value Peak value to r.m.s value R.M.S. value to peak value Peak value to average value R.M.S. value to average value Peak value to r.m.s value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) DC series motors are best suited for traction work because Torque and speed are proportional to the square of the armature current Torque and speed are inversely proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Its torque is proportional to the square of the armature current and speed is directional proporational to torque Torque and speed are proportional to the square of the armature current Torque and speed are inversely proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Its torque is proportional to the square of the armature current and speed is directional proporational to torque ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²N α 1/φN α 1/T
DGVCL Exam Paper (11-12-2011) In a power plant, a reserve generating capacity which is not in service but is in operation is known as Spinning reserve Cold reserve Hot reserve Firm power Spinning reserve Cold reserve Hot reserve Firm power ANSWER DOWNLOAD EXAMIANS APP
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