Electrical Machines In a dc machine 72 number of coils are used. Find the number of commutator segments required? 74 37 72 36 74 37 72 36 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Transformer core is laminated to reduce both 1 and 2. hysteresis loss. copper loss. eddy current loss. both 1 and 2. hysteresis loss. copper loss. eddy current loss. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Mechanical energy is supplied to DC generator at the rate of 4200 J / s. The generator delivers 32.2 Amp at 120 V. What is the percentage efficiency of the generator? 212 V. 201.02 V. 210 V. 205 V. 212 V. 201.02 V. 210 V. 205 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 2, 5 1, 3, 5 1, 2, 6 1, 4, 6 1, 2, 5 1, 3, 5 1, 2, 6 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 3 - Φ, 400 / 200 V, Y - Y connected wound rotor induction motor has 0.06 Ω rotor resistance and 0.3 Ω standstill reactance per phase. To make the starting torque equal to maximum torque of the motor the additional resistance required 0.66 Ω. 0.24 Ω. 0.45 Ω. 0.78 Ω. 0.66 Ω. 0.24 Ω. 0.45 Ω. 0.78 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC motor with armature resistance of 0.5 ohms connected directly to a 220 Volt supply. If the armature is stationary then the current flowing through the armature is 570 A. 250 A. 340 A. 440 A. 570 A. 250 A. 340 A. 440 A. ANSWER DOWNLOAD EXAMIANS APP