Electrical Machines An ideal DC generated is one that has _____________ voltage regulation. zero. negative. low. positive. zero. negative. low. positive. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the back emf in DC motor vanishes suddenly the motor will run at very high speed. run at very low speed. start haunting. burn. run at very high speed. run at very low speed. start haunting. burn. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 1.8 9 Ω 3.1 Ω 1.79 Ω 2 .1 Ω 1.8 9 Ω 3.1 Ω 1.79 Ω 2 .1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Larger values of air flux density is taken while designing IM for larger bore diameter. larger output. both. none. larger bore diameter. larger output. both. none. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The following statements relate to compensating winding (CW) and interpole winding (IW) of a dc machine : 1. CW neutralizes the armature reaction under a pole pitch 2. IW is connected in series with armature circuit 3. IW produces mmf in the commutating zone only 4. CWmmf is directed along the brush axis 5. Mmf produced by IW is equal to armature mmf From these, the correct statements are 2, 3, 4 1, 3, 4, 5 2, 3, 4, 5 1, 2, 3, 4 and 5 2, 3, 4 1, 3, 4, 5 2, 3, 4, 5 1, 2, 3, 4 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The function of field regulator in a DC compound motor is to vary the armature resistance. limit the armature current. control field current. none of above. vary the armature resistance. limit the armature current. control field current. none of above. ANSWER DOWNLOAD EXAMIANS APP