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 ) 2000 Volt. 0 Volt. 1500 Volt. 1600 Volt. 2000 Volt. 0 Volt. 1500 Volt. 1600 Volt. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Kh is hysteresis constant, f is supply frequency, Bm maximum flux density in core of transformer, the expression of hysteresis loss in transformer, is given by KhfBm3. KhfBm1.6. KhfBm. Khf2Bm1.6. KhfBm3. KhfBm1.6. KhfBm. Khf2Bm1.6. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements about commutating poles which are fitted on most large dc Shunt motors: 1. The commutating poles are placed in the geometric neutral plane and their number is usually Equal to the number of main poles 2. The winding on the commutating poles is connected in series with the shunt-field winding on the main poles 3. The polarity of the commutating pole must be that of the next pole further ahead 4. The commutating poles neutralize the reactance voltage produced in the coil undergoing Commutation. Of these statements, 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct 1, 2 and 3 are correct 1 and 4 are correct 1, 2 and 4 are correct 2, 3 and 4 are correct ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : 1. interpole windings are connected in series with armature windings 2. polarity of interpoles must be the same as that of the main poles in advance 3. distortion of the main field under the pole shoes is not affected by the use of interpoles From above, the correct answer is 2 and 3 1 and 2 1 and 3 1 alone 2 and 3 1 and 2 1 and 3 1 alone ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Series field consists of--------number of turns and ---------- conductors respectively less and thick large and thick less and thin large and thin less and thick large and thick less and thin large and thin ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The brush-axis of a bipolar dc motor is rotated by 90°. The effect of this rotation on the back emf Eband the torque developed Tdwould be such that both Eb and Td are unchanged Eb is zero, but Td is unchanged both Eb and Td are zero Eb is unchanged, but Td is zero both Eb and Td are unchanged Eb is zero, but Td is unchanged both Eb and Td are zero Eb is unchanged, but Td is zero ANSWER DOWNLOAD EXAMIANS APP