DGVCL Exam Paper (12-06-2016) What will happen if the primary of a transformer is connected to DC supply? Transformer will operate with high efficiency No effect Transformer will operate with low efficiency Transformer may start to smoke and burn Transformer will operate with high efficiency No effect Transformer will operate with low efficiency Transformer may start to smoke and burn ANSWER EXPLANATION DOWNLOAD EXAMIANS APP transformer works on principle of faraday's law of electromagnetic induction. So if D.C supply use, no indction are produced and due to this E.M.F not induced in winding and transfer of electrical energy is not possible.
DGVCL Exam Paper (12-06-2016) Which of the following circuit breakers has high reliability & minimum maintenance? Sulphur hexafluoride CB Air blast CB Bulk oil type CB Vacuum CB Sulphur hexafluoride CB Air blast CB Bulk oil type CB Vacuum CB ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) The kVA rating of Three-phase transformer with Voltage = 200 V and Current = 100 A will be : 34.64 kVA 75 kVA None of these 20 kVA 34.64 kVA 75 kVA None of these 20 kVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP For three phase,VA = √3 V IFor single phase, kVA = V I
DGVCL Exam Paper (12-06-2016) Isolator in substation is open under _____ condition. Short circuit None of these No load Full load Short circuit None of these No load Full load ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Isolators do not have capacity to make or breake circuit when current flowing in circuit
DGVCL Exam Paper (12-06-2016) Efficiency of a power transformer is of the order of : 0.25 0.98 1 0.5 0.25 0.98 1 0.5 ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) Earthing switch is used for? All of these Measuring of safety voltage Discharging residual energies Protection of equipment from ground faults All of these Measuring of safety voltage Discharging residual energies Protection of equipment from ground faults ANSWER DOWNLOAD EXAMIANS APP
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