Electrical Machines If the temperature of armature resistance is increased, the speed of a series motor would None of above. not change. decrease. increase. None of above. not change. decrease. increase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A three phase 400 V, 6 pole, 50 Hz, squirrel cage induction motor is running at a slip of 5%. The speed of stator magnetic field with respect to rotor magnetic field and speed of rotor w.r.t stator magnetic field are 1000 rpm, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. zero, 950 rpm. 1000 rpm, 950 rpm. 1000 rpm, - 50 rpm. zero , - 50 rpm. zero, 950 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Commutators in DC machines have a role of which converts Both AC to DC and DC to AC. AC to DC. high voltage DC to low voltage DC. none of these. Both AC to DC and DC to AC. AC to DC. high voltage DC to low voltage DC. none of these. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An 8 pole DC generator has 500 armature conductors and useful flux per pole of 0.065 Wb. What will be the emf generated if it is lap connected and runs at 1000 rpm. What must be the speed at which it is driven to produce the same emf if it is wave wound? 2166.67V, 270 rpm. 541.67V, 200 rpm. 541.67V, 250 rpm. 2166.67V, 230 rpm. 2166.67V, 270 rpm. 541.67V, 200 rpm. 541.67V, 250 rpm. 2166.67V, 230 rpm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 59.2%. 48.0%. 57.1%. 88.8%. 59.2%. 48.0%. 57.1%. 88.8%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature of DC machine is made of silicon steel lamination to increase the permeability. reduce hysteresis loss only. reduce both eddy current and hysteresis loss. reduce eddy current loss only. increase the permeability. reduce hysteresis loss only. reduce both eddy current and hysteresis loss. reduce eddy current loss only. ANSWER DOWNLOAD EXAMIANS APP
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