Electrical Machines The emf induced in a conductor rotating in a bipolar field is both of above. AC. DC. None of these both of above. AC. DC. None of these ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of generated emf in the armature coil of a DC machine is 1. the same as that of the current in a generator 2. the same as that of the current in a motor 3. opposite to that of the current in a generator 4. opposite to that of the current in a motor From these, the correct answer is 1, 4 2, 4 2, 3 1, 3 1, 4 2, 4 2, 3 1, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A large series motor is never started without some mechanical on it because otherwise it will Develop excessive speed and damage itself. Produce sparking at brushes. Draw too much current. Open fuse or circuit breaker. Develop excessive speed and damage itself. Produce sparking at brushes. Draw too much current. Open fuse or circuit breaker. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Short circuiting is caused in the armature winding due to grounding of two or more turns of the same coil. failure of insulation between two commutator bars. failure of insulation between two turns of coil. any of above. grounding of two or more turns of the same coil. failure of insulation between two commutator bars. failure of insulation between two turns of coil. any of above. 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 3.1 Ω 1.79 Ω 1.8 9 Ω 2 .1 Ω 3.1 Ω 1.79 Ω 1.8 9 Ω 2 .1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor power output of 3-phase induction motor is 15 KW. The rotor copper losses at a slip of 4% will be 700 W 600 W 650 W 625 W 700 W 600 W 650 W 625 W ANSWER DOWNLOAD EXAMIANS APP
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