Electrical Machines Under commutation results in sparking the trailing edge of the brush. sparking at the middle of the brush. sparking at the leading edge of the brush. no sparking. sparking the trailing edge of the brush. sparking at the middle of the brush. sparking at the leading edge of the brush. no sparking. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC generator, if P be the number of poles and N be the rpm of the rotor, then frequency of magnetic reversals will be PN/3000. PN/60. PN/120. PN/2. PN/3000. PN/60. PN/120. PN/2. 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 applied voltage. Back emf is equal to zero. None of above. Back emf is equal to half the applied voltage. Back emf is equal to applied voltage. Back emf is equal to zero. None of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a motor falls from 1100 r.p.m at no-load to 1050 r.p.m at rated load. The speed regulation of motor is 2.56 %. 3.76%. 4.76%. 2.57 %. 2.56 %. 3.76%. 4.76%. 2.57 %. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Ra maximum and Rf maximum Ra maximum and Rf minimum Ra minimum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf maximum Ra maximum and Rf minimum Ra minimum and Rf minimum Rf maximum and Ra minimum ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which type of motors uses slip rings? Induction motors Synchronous motors Both Synchronous and Induction motor DC Shunt Motor Induction motors Synchronous motors Both Synchronous and Induction motor DC Shunt Motor ANSWER DOWNLOAD EXAMIANS APP
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