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 Hot reserve Firm power Cold reserve Spinning reserve Hot reserve Firm power Cold reserve Spinning reserve ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) If a relay fails to operate inspite of a fault in its own zone of protection, it is said to Under reach Pick up Reach Over reach Under reach Pick up Reach Over reach ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The purpose of interpoles in DC machines is to nullify The cross-magnetizing effect of armature mmf The demagnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage The reactance voltage The cross-magnetizing effect of armature mmf The demagnetizing effect of armature mmf Both the cross-magnetizing mmf and the reactance voltage The reactance voltage ANSWER EXPLANATION DOWNLOAD EXAMIANS APP interpoles is widely use to improve commutationplace between main poles fitted to yokefunctions:to neutralize armature mmf in commutating zoneto produce some flux in commutating zone
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 % 6 % 4 % 5 % 0.4 % 6 % 4 % 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) In carrier current protection, the purpose of the wave trap is for Trapping power frequency waves All of these Trapping high frequency waves entering into generator/transformer unit. Tripping fault current Trapping power frequency waves All of these Trapping high frequency waves entering into generator/transformer unit. Tripping fault current ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Shunt motor Series motor Cumulatively compounded motor Differentially compounded motor Shunt motor Series motor Cumulatively compounded motor Differentially compounded motor ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²starting torque of dc series motor is high