DGVCL Exam Paper (11-12-2011) An over excited synchronous motor draws current at Leading power factor Unity power factor Lagging power factor Depends on nature of load Leading power factor Unity power factor Lagging power factor Depends on nature of load ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Over excitation : leading currentUnder excitation : lagging currentNormal excitation : current with unity PF (in phase current)
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 % 6 % 5 % 0.4 % 4 % 6 % 5 % 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) Which lightning stroke is most dangerous? Direct stroke on line conductor Direct stoke on tower top Indirect stroke on conductor Direct stroke on ground wire Direct stroke on line conductor Direct stoke on tower top Indirect stroke on conductor Direct stroke on ground wire ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A fuse wire should have Low specific resistance and low melting point Low specific resistance and high melting point High specific resistance and high melting point High specific resistance and low melting point Low specific resistance and low melting point Low specific resistance and high melting point High specific resistance and high melting point High specific resistance and low melting point ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) In a power plant, a reserve generating capacity which is not in service but is in operation is known as Cold reserve Firm power Spinning reserve Hot reserve Cold reserve Firm power Spinning reserve Hot reserve 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 avoids core saturation and high voltage induction It protects the primary ciruits It protects the secondary ciruits It is safe to human beings It avoids core saturation and high voltage induction It protects the primary ciruits ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS