DGVCL Exam Paper (12-06-2016) A Transformer _____ 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 Changes AC to DC 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: Transformer may start to smoke and burn Eddy Current and Hysteresis losses will be excessive No effect Current will be too much high Transformer may start to smoke and burn Eddy Current and Hysteresis losses will be excessive No effect 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 rating of transformer may be expressed in _____ kW kVA kVAR Horse power kW kVA kVAR Horse power ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Equipment : RatingTransformer : kVAAlternator : kVAMotor : kW/HPBattery : ampere-hour
DGVCL Exam Paper (12-06-2016) Induction cup relay is operated due to changes in : All of these Voltage Impedance Current All of these Voltage Impedance Current ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) The main disadvantages of having poor power factors are: Poor voltage regulation High energy loss in conductor High cost of station and distribution equipment All of these Poor voltage regulation High energy loss in conductor High cost of station and distribution equipment All of these ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) The friction losses in Real Transformers are : 0.25 0 0.05 0.5 0.25 0 0.05 0.5 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP As there is no rotating part in transformer, there is no friction and windage loss