DGVCL Exam Paper (11-12-2011) A 3 phase, 6 pole induction motor operates on 440 V, 50 Hz, supply. If the actual speed of the motor is 960 rpm the slip will be 0.4 % 4 % 5 % 6 % 0.4 % 4 % 5 % 6 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Ns = 120f/PSlip=(Ns-Nr)/NsNs = 1000 and Nr = 960 from equation of slip, S = (1000-960)/1000S = 0.04 or 4%
DGVCL Exam Paper (11-12-2011) What happens to the contents of RAM (Random Access Memory) when the power of the computer is turned off? Content remains intact Content gets corrupted Content is lost Content is transferred to other memory Content remains intact Content gets corrupted Content is lost Content is transferred to other memory ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Under operating conditions, the secondary of a current transformer is always short ciruited because It protects the secondary ciruits It is safe to human beings It protects the primary ciruits It avoids core saturation and high voltage induction It protects the secondary ciruits It is safe to human beings It protects the primary ciruits It avoids core saturation and high voltage induction ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The advantage of slipring induction motor over the squirrel cage induction motor is It is suitable for higher speeds It can be started with the help of rotor resistances It has a higher efficiency It's power factor is higher It is suitable for higher speeds It can be started with the help of rotor resistances It has a higher efficiency It's power factor is higher ANSWER EXPLANATION DOWNLOAD EXAMIANS APP slip ring motor have high starting torque compare to squirrel cage motor and have good speed controlalso have high over loading capacity, smooth acceleration under heavy loads.
DGVCL Exam Paper (11-12-2011) The corona effect can be minimized by increasing Spacing between the conductors Both spacing between the conductors and diameter of the conductor The length of the conductor Diameter of the conductor Spacing between the conductors Both spacing between the conductors and diameter of the conductor The length of the conductor Diameter of the conductor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Corona can be reduced by using large size of conductor, bundle conductor and hollow conductor.
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