Electrical Machines The frequency of voltage generated by an alternator having 8 poles and rotating at 250 rpm is 60 Hz. 16.67 Hz. 50 Hz. 25 Hz. 60 Hz. 16.67 Hz. 50 Hz. 25 Hz. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole dynamo with wave wound armature has 51 slots contains 20 conductors in each slot. If induced emf 357 Volts and speed is 8500 rpm, flux per pole will be 2.7 mWb. 1.4 mWb. 3.5 mWb. 1.2 mWb. 2.7 mWb. 1.4 mWb. 3.5 mWb. 1.2 mWb. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Shunt Motor the speed can be increased by Decreasing the field current. Increasing the armature current. Increasing the field current. Increasing the field current. Decreasing the field current. Increasing the armature current. Increasing the field current. Increasing the field current. 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, 6 1, 2, 5 1, 3, 5 1, 4, 6 1, 2, 6 1, 2, 5 1, 3, 5 1, 4, 6 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the applied voltage of a DC motor is 230 V, then back emf, for maximum power developed is 200 V. 115 V. 230 V. 460 V. 200 V. 115 V. 230 V. 460 V. 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 1 alone 2 and 3 1 and 3 1 and 2 1 alone 2 and 3 1 and 3 1 and 2 ANSWER DOWNLOAD EXAMIANS APP