DGVCL Exam Paper (12-06-2016) The following is correct : P = I²xR P = V²/R P = VxI All of these P = I²xR P = V²/R P = VxI All of these ANSWER EXPLANATION DOWNLOAD EXAMIANS APP True for DC Circuits.For single pahse ac P = V I CosØ
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: Current will be too much high Eddy Current and Hysteresis losses will be excessive Transformer may start to smoke and burn No effect Current will be too much high Eddy Current and Hysteresis losses will be excessive Transformer may start to smoke and burn No effect 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 friction losses in Real Transformers are : 0.5 0.25 0 0.05 0.5 0.25 0 0.05 ANSWER EXPLANATION DOWNLOAD EXAMIANS APP As there is no rotating part in transformer, there is no friction and windage loss
DGVCL Exam Paper (12-06-2016) The voltage of transmission can be regulated by Use of tap changing transformers Use of capacitors to neutralize the effect of series reactance Switching in shunt capacitors at the receiving end during heavy loads Any of the above methods Use of tap changing transformers Use of capacitors to neutralize the effect of series reactance Switching in shunt capacitors at the receiving end during heavy loads Any of the above methods ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (12-06-2016) The rating of fuse wire is always expressed in _____ Ampere-volts Ampere-hours Amperes kWh Ampere-volts Ampere-hours Amperes kWh ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Equipment :Rating Fuse : AmpereTransformer : kVAAlternator : kVAMotor : kW/HPBattery : ampere-hour
DGVCL Exam Paper (12-06-2016) A certain transformer has 200 turns in the primary winding, 50 turns in the secondary winding and 120 volts applied to the primary. What is the voltage across the secondary? 30 Volts 480 Volts 60 Volts 120 Volts 30 Volts 480 Volts 60 Volts 120 Volts ANSWER EXPLANATION DOWNLOAD EXAMIANS APP For transformer, V2/V1 = N2/N1V2/120 = 50/200V2 = 30 V
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