Electrical Machines In a loaded DC generator, if the brushes are given a shift from the interpolar axis in the direction of rotation, then the commutation will deteriorate with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with fall of terminal voltage. improve with rise in terminal voltage. deteriorate with rise in terminal voltage. deteriorate with fall of terminal voltage. improve with fall of terminal voltage. improve with rise in terminal voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The DC generator runs at a speed of 1000 rpm and flux per pole is 0.2 Wb, number of poles are 2 the winding is wave wound and having 480 conductors. The critical speed is 1200 rpm. Then the generated emf ( Eg ) 1500 Volt. 2000 Volt. 1600 Volt. 0 Volt. 1500 Volt. 2000 Volt. 1600 Volt. 0 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Frequency should be same Terminal voltage is same Speed of alternators should be same Both 1and 2 Frequency should be same Terminal voltage is same Speed of alternators should be same Both 1and 2 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The results of a slip test for determining direct axis (Xd) and quadrature axis (Xq) reactances of a star connected salient pole alternator are given below Phase values: Vmax = 108 V ; Vmin = 96 V Imax = 12 A ; Imin = 10 A Hence the two reactances will be Xd = 9.6Ω and Xq = 9Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 8Ω and Xq = 10.8Ω Xd = 9.6Ω and Xq = 9Ω Xd = 10.8Ω and Xq = 8Ω Xd = 9Ω and Xq = 9.6Ω Xd = 8Ω and Xq = 10.8Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of following methods are suitable for the speed control of squirrel cage induction motor? 1. Voltage control. 2. Frequency control. 3. Pole changing method. 4. Rotor resistance control select the correct answer using the codes given below:- 2, 3 and 4. 2 and 4. 1, 2 and 3. 1, 3 and 4. 2, 3 and 4. 2 and 4. 1, 2 and 3. 1, 3 and 4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 5 KVA transformer has a turns ratio of N1/N2 = 10. The impedance of primary winding is 3+j5 ohms while that of secondary winding is 0.5+j0.8 ohms. The impedance of transformer when referred to primary will be 53+j85 ohms 8+j13 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms 53+j85 ohms 8+j13 ohms 3.05+j5.08 ohms 3.5+j5.8 ohms ANSWER DOWNLOAD EXAMIANS APP
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