Electrical Machines Hysteresis loss is proportional to f1.5. f3. f2. f. f1.5. f3. f2. f. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a DC compound motor can be reversed by interchanging shunt field connections. armature or field connections. armature connections. series field connections. shunt field connections. armature or field connections. armature connections. series field connections. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 2 and 3 1, 2, 3 and 5 1 and 3 1, 3 and 5 1, 2 and 3 1, 2, 3 and 5 1 and 3 1, 3 and 5 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 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 1, 2 and 3 are correct 1 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 1 alone 1 and 2 1 and 3 2 and 3 1 alone 1 and 2 1 and 3 2 and 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The volt-ampere euation for a long-shunt compound motor is given by Vt = Ea + Iara+ ILrs Vt= Ea + Iara Vt= Ea– Iara Vt = Ea + Ia(ra + rs) Vt = Ea + Iara+ ILrs Vt= Ea + Iara Vt= Ea– Iara Vt = Ea + Ia(ra + rs) ANSWER DOWNLOAD EXAMIANS APP