Electrical Machines Transformer action requires a alternating magnetic lux. constant magnetic flux. alternating electric flux. increasing magnetic flux. alternating magnetic lux. constant magnetic flux. alternating electric flux. increasing magnetic flux. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The magnetic field which initially induces emf in the armature in a self excited DC generator is because of residual magnetism. None of these armature reaction. permanent magnets. residual magnetism. None of these armature reaction. permanent magnets. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3 - Φ IM in order to eliminate cogging the number of stator slots must be equal to number of rotor slots. an integral multiple of number of rotor slots. unequal to number of rotor slots and skewed in shape. either (B) or (C). equal to number of rotor slots. an integral multiple of number of rotor slots. unequal to number of rotor slots and skewed in shape. either (B) or (C). 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 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 1.5 to 2. 2 to 3. 1.0. 3 to 5. 1.5 to 2. 2 to 3. 1.0. 3 to 5. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The result of slip test on a 3-phase, 20 KVA, 400 V, 50 Hz connected salient pole alternator is given below- Phase value: Vmax = 100 V, Vmin = 96 V, Imax = 10 A and I min = 7 A. The direct and quadranature axis reactances are respectively 14.28 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 9.60 Ω. 8.248 and 5.54 Ω. 14.28 and 9.60 Ω. 14.28 and 5.54 Ω. 8.248 and 9.60 Ω. 8.248 and 5.54 Ω. ANSWER DOWNLOAD EXAMIANS APP
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