DGVCL Exam Paper (11-12-2011) The main advantage of using fractional pitch winding is to refuce Cost of the machine Size of the machine Amount of copper in the winding Harmonics in the generated emf Cost of the machine Size of the machine Amount of copper in the winding Harmonics in the generated emf ANSWER EXPLANATION DOWNLOAD EXAMIANS APP due to fractional pitch EMF can be approximately made into sine wavelosses due to harmonics reducedsaving in conductor materialmechanical strength of coil is increased.
DGVCL Exam Paper (11-12-2011) DC series motors are best suited for traction work because Its torque is proportional to the square of the armature current and speed is directional proporational to torque Torque and speed are proportional to the square of the armature current Torque and speed are inversely proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is inversely proportional to torque Its torque is proportional to the square of the armature current and speed is directional proporational to torque Torque and speed are proportional to the square of the armature current Torque and speed are inversely proportional to the square of the armature current Its torque is proportional to the square of the armature current and speed is inversely proportional to torque ANSWER EXPLANATION DOWNLOAD EXAMIANS APP Torque in d.c motor = k* φ * IaIn series motor φ α IaTα I²N α 1/φN α 1/T
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 % 5 % 6 % 4 % 0.4 % 5 % 6 % 4 % 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) Rated making capacity of a ciruit breaker is equal to 1.11 X rated symmetrical breaking capacity Rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity 1.11 X rated symmetrical breaking capacity Rated symmetrical breaking capacity √2 X rated symmetrical breaking capacity 2.55 X rated symmetrical breaking capacity ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) A fuse wire should have Low specific resistance and low melting point High specific resistance and high melting point High specific resistance and low melting point Low specific resistance and high melting point Low specific resistance and low melting point High specific resistance and high melting point High specific resistance and low melting point Low specific resistance and high melting point ANSWER DOWNLOAD EXAMIANS APP
DGVCL Exam Paper (11-12-2011) All the peripheral devices connected to a computer require power to work. Which of the following voltages is required for the motherboard to work? Negative cycle of sine wave DC AC Positive cycle of sine wave Negative cycle of sine wave DC AC Positive cycle of sine wave ANSWER DOWNLOAD EXAMIANS APP
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