DGVCL Exam Paper (11-12-2011) What type of insulator is used if the direction of the transmission line is to be changed? Strain type Suspebsion type Pin type Shakle type Strain type Suspebsion type Pin type Shakle type ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Transposition of transmission line is done to Balance line voltage drop Reduce corona Reduce line loss Reduce skin effect Balance line voltage drop Reduce corona Reduce line loss Reduce skin effect 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
DGVCL Exam Paper (11-12-2011) The form factor in AC means the ration of R.M.S. value to average value Peak value to average value Peak value to r.m.s value R.M.S. value to peak value R.M.S. value to average value Peak value to average value Peak value to r.m.s value R.M.S. value to peak value ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The efficiency of a transformer at full load, 0.8 p.f. lag is 90%. Its efficiency at full load, 0.8 p.f. lead will be More than 90% 80 % Less than 90% 90 % More than 90% 80 % Less than 90% 90 % ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Efficiency= output power/input powerefficiency = (v*i*cosφ)/((v*i*cosφ)+(x² Pc)+(Pi)) x=fractional part of full load
DGVCL Exam Paper (11-12-2011) If the excitation of a synchronous generator fails, it acts as a Synchronous motor Induction motor Induction generator Synchronous generator Synchronous motor Induction motor Induction generator Synchronous generator ANSWER EXPLANATION DOWNLOAD EXAMIANS APP if excitation of synchronous generator fails, operate as induction motor