DGVCL Exam Paper (11-12-2011) Ybus used in power flow studies and Zbus used in short circuit studies Are the same Have no inter relation Are transpose of each other Are inverse of each other Are the same Have no inter relation Are transpose of each other Are inverse of each other ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which type of back up protection is widely used for the protection of transmission lines? Breaker backup Relay backup Control backup Remote backup Breaker backup Relay backup Control backup Remote backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) First zone distance relay protects the transmission line section upto 25 % of its full length 50 % of its full length Its full length 80 % of its full length 25 % of its full length 50 % of its full length Its full length 80 % of its full length 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 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 inversely proportional to the square of the armature current Torque and speed are 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 inversely 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) The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be 80 % More than 90% Less than 90% 90 % 80 % More than 90% Less than 90% 90 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Efficiency= output power/input powerefficiency = (v*i*cosφ)/((v*i*cosφ)+(x² Pc)+(Pi)) x=fractional part of full load
DGVCL Exam Paper (11-12-2011) At time t= 0+ , with zero initial condition, which of the following acts as a short circuit? Conductor Capacitor Voltage source Resistor Conductor Capacitor Voltage source Resistor ANSWER DOWNLOAD EXAMIANS APP
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