DGVCL Exam Paper (11-12-2011) The corona effect can be minimized by increasing The length of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors Diameter of the conductor The length of the conductor Both spacing between the conductors and diameter of the conductor Spacing between the conductors 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) It is difficult interrupt a capacitive current because The restriking voltage can be high Stored energy in the capacitor is very high It has a leading power factor Current magnitude is very small The restriking voltage can be high Stored energy in the capacitor is very high It has a leading power factor Current magnitude is very small ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Due to skin effect Portion of the conductor near the surface carries less current and the core of the conductor carries more current Current flows through the half cross section of the conductor Portion of the conductor near the surface carries more current and the core of the conductor carries less current Uniform current flows through the conductor Portion of the conductor near the surface carries less current and the core of the conductor carries more current Current flows through the half cross section of the conductor Portion of the conductor near the surface carries more current and the core of the conductor carries less current Uniform current flows through the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Skin Effect:tendency of the current to crowd near the conductor surface.Skin effect is proportional to frequency, conductor diameter and permiability. Skin effect increases effective resistance of conductor.In DC, no skin effect.
DGVCL Exam Paper (11-12-2011) Which type of back up protection is widely used for the protection of transmission lines? Breaker backup Control backup Relay backup Remote backup Breaker backup Control backup Relay backup Remote backup ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Series motor Differentially compounded motor Cumulatively compounded motor Shunt motor Series motor Differentially compounded motor Cumulatively compounded motor Shunt 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
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 Open isolator close circuit breaker-open earthing switch Close circuit breaker-close isolator - open earthing switch Open circuit breaker-open isolator-close earthing switch Close earthing switch - open ciruit- breaker-open islotor Open isolator close circuit breaker-open earthing switch Close circuit breaker-close isolator - open earthing switch ANSWER DOWNLOAD EXAMIANS APP
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