Electrical Machines In travelling cranes for hoisting and lowering which type of motor is preferred? DC series motor. AC slip ring motor. Single phase induction motor. Synchronous motor. DC series motor. AC slip ring motor. Single phase induction motor. Synchronous motor. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V dc series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 Ω. The value of resistance which must be added to obtain rated torque at 1000 rpm is 1.9 Ω 5.7 Ω 6 Ω 2.2 Ω 1.9 Ω 5.7 Ω 6 Ω 2.2 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For higher values of armature, the speed of a DC series motor is Inversely proportional to armature current. Proportional to armature current. Constant. Proportional to the square of armature current. Inversely proportional to armature current. Proportional to armature current. Constant. Proportional to the square of armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by a 220 V DC series motor of armature resistance 0.5 Ω and back emf of 200 V is 40 A. 400 A. 44 A. 440 A. 40 A. 400 A. 44 A. 440 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When pure inductive load is connected to the alternator, what is the effect of armature reaction? Magnetization Demagnetization Cross magnetization None of these Magnetization Demagnetization Cross magnetization None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a dc generator operating on load with its brushes on the geometrical neutral axis (GNA), the magnetic neutral axis (MNA) is shifted in the direction of rotation. Now, if the brushes are given a lead of 90° (electrical), then the MNA will shift forward by more than 90° shift forward by less than 90° shift forward by 90° coincide with the GNA shift forward by more than 90° shift forward by less than 90° shift forward by 90° coincide with the GNA ANSWER DOWNLOAD EXAMIANS APP
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