DGVCL Exam Paper (11-12-2011) If the percentage reactance of the system upto the point of fault is 20% and the base kVA is 10,000 the short ciruit kVA is 50 MVA 20 MVA 10 MVA 60 MVA 50 MVA 20 MVA 10 MVA 60 MVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Short circuit kVA = Base kVA/%X
DGVCL Exam Paper (11-12-2011) Bulk power transmission over long HVDC lines are preferred on account of Low cost of HVDC terminals Simple protection Minimum line power losses No harmonic problems Low cost of HVDC terminals Simple protection Minimum line power losses No harmonic problems ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) DC series motors are best suited for traction work because 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 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 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 corona effect can be minimized by increasing Spacing between the conductors Both spacing between the conductors and diameter of the conductor The length of the conductor Diameter of the conductor Spacing between the conductors Both spacing between the conductors and diameter of the conductor The length of the conductor Diameter of the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Corona can be reduced by using large size of conductor, bundle conductor and hollow conductor.
DGVCL Exam Paper (11-12-2011) Transposition of transmission line is done to Balance line voltage drop Reduce line loss Reduce corona Reduce skin effect Balance line voltage drop Reduce line loss Reduce corona Reduce skin effect ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which of the following correctly represents the sequence of operations of isolator, circiut breaker and earthing switch while opening a circuit? Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Close circuit breaker-close isolator - open earthing switch Open isolator close circuit breaker-open earthing switch Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Close circuit breaker-close isolator - open earthing switch Open isolator close circuit breaker-open earthing switch ANSWER DOWNLOAD EXAMIANS APP
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