DGVCL Exam Paper (11-12-2011) In the protection of transformers, harmonic restraint is used to guard against Lightning Switching over voltages Magnetizing inrush current Unbalanced protection Lightning Switching over voltages Magnetizing inrush current Unbalanced protection 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) DC series motors are best suited for traction work because 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 directional proporational to torque Its torque is proportional to the square of the armature current and speed is inversely proportional 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 directional proporational to torque Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Torque and speed are proportional to the square of the armature current 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 carrier current protection, the purpose of the wave trap is for All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. Trapping power frequency waves All of these Tripping fault current Trapping high frequency waves entering into generator/transformer unit. Trapping power frequency waves ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto 80 % of its full length 25 % of its full length Its full length 50 % of its full length 80 % of its full length 25 % of its full length Its full length 50 % of its full length ANSWER DOWNLOAD EXAMIANS APP
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 minimum and power factor is 0.5 Current is maximum and power factor is 0.5 Current is minimum and power factor is unity Current is maximum and power factor is unity Current is minimum and power factor is 0.5 Current is maximum and power factor is 0.5 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Cumulatively compounded motor Differentially compounded motor Shunt motor Series motor Cumulatively compounded motor Differentially compounded motor Shunt motor Series motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²starting torque of dc series motor is high
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