Electrical Machines How can the synchronous speed of a 3 - Φ IM be varied? 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). By varying number of poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The function of field regulator in a DC compound motor is to control field current. vary the armature resistance. limit the armature current. none of above. control field current. vary the armature resistance. limit the armature current. none of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods are used to control the speed of DC motors is armature circuit resistance control All of these field current control supply voltage control armature circuit resistance control All of these field current control supply voltage control ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines DC motors are stopped by opening line switches and not by forcing the handle of the motor starter back to OFF position. This is due to occurance of Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. Both of above. None of these. Heavy sparking at brushes. Heavy sparking at the first stud of starting resistance steps. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Belt conveyors offer _______________ starting torque. zero. medium. high. low. zero. medium. high. low. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is the mechanical power developed by a DC series motor is maximum? Back emf is equal to half the applied voltage. Back emf is equal to zero. Back emf is equal to applied voltage. None of above. Back emf is equal to half the applied voltage. Back emf is equal to zero. Back emf is equal to applied voltage. None of above. ANSWER DOWNLOAD EXAMIANS APP
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