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 Transformer may start to smoke and burn Transformer will operate with low efficiency No effect Transformer will operate with high efficiency Transformer may start to smoke and burn Transformer will operate with low efficiency No effect 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) As per Electricity Act, _____ means any line which is used for carrying electricity for any purpose. All of these Electric line None of these Transmission line All of these Electric line None of these Transmission line ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) What would happen if a power transformer designed for operation on 50 Hz (frequency) were connected to a 500 Hz (frequency) source of the same voltage: No effect Transformer may start to smoke and burn Eddy Current and Hysteresis losses will be excessive Current will be too much high No effect Transformer may start to smoke and burn Eddy Current and Hysteresis losses will be excessive Current will be too much high ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Core loss of transformer = Hysteresis loss + eddy current lossHysteresis loss prpotional to feddy current loss prpotional to f².
DGVCL Exam Paper (12-06-2016) The kVA rating of Three-phase transformer with Voltage = 200 V and Current = 100 A will be : 20 kVA None of these 75 kVA 34.64 kVA 20 kVA None of these 75 kVA 34.64 kVA ANSWER EXPLANATION DOWNLOAD EXAMIANS APP For three phase,VA = √3 V IFor single phase, kVA = V I
DGVCL Exam Paper (12-06-2016) A Transformer _____ Changes AC to DC Changes DC to AC Steps up or down AC Voltages & Current Steps up or down DC Voltages & Current Changes AC to DC Changes DC to AC Steps up or down AC Voltages & Current Steps up or down DC Voltages & Current ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) Where is RAM located? Mother Board External Drive All of above Expansion Board Mother Board External Drive All of above Expansion Board ANSWER DOWNLOAD EXAMIANS APP
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