Electrical Machines A DC cumulatively compounded motor delivers rated load torque at rated speed. If the series field is short-circuited, then the armature current and speed will increase and decrease respectively both increase decrease and increase respectively both decrease increase and decrease respectively both increase decrease and increase respectively both decrease ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). By varying number of poles. By varying the supply frequency. By varying supply voltage. Both (A) and (B). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of stator rotating magnetic field (RMF) with respect to rotor is S.Ns Zero Ns Nr S.Ns Zero Ns Nr ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 200 V DC machine supplies 20 A at 200 V as a generator. The armature resistance is 0.2 Ω. If the machine is now operated as a motor at same terminal voltage and current but with the flux increased by 10%, the ratio of motor speed to generator speed is 0.87 0.95 0.96 1.06 0.87 0.95 0.96 1.06 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 3 to 5. 1.5 to 2. 1.0. 2 to 3. 3 to 5. 1.5 to 2. 1.0. 2 to 3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If direct axis reactance Xd and quadrature axis reactance Xq are equal, then reluctance power is zero maximum minimum All of these zero maximum minimum All of these ANSWER DOWNLOAD EXAMIANS APP