DGVCL Exam Paper (11-12-2011) The purpose of providing a choke in a tube light is To avoid radio interference To limit the current to an appropriate value To improve the power factor To eliminate corona effect To avoid radio interference To limit the current to an appropriate value To improve the power factor To eliminate corona effect ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) At time t= 0+ , with zero initial condition, which of the following acts as a short circuit? Voltage source Resistor Capacitor Conductor Voltage source Resistor Capacitor Conductor ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) Which motor is used to start heavy loads? Cumulatively compounded motor Shunt motor Series motor Differentially compounded motor Cumulatively compounded motor Shunt motor Series 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) A device connected to the computer which converts digital signals to analog and vice-versa is Modem CPU Keyboard UPS Modem CPU Keyboard UPS ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) The advantage of slipring induction motor over the squirrel cage induction motor is 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 It is suitable for higher speeds It can be started with the help of rotor resistances 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 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 90 % More than 90% Less than 90% 80 % 90 % More than 90% Less than 90% 80 % 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
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