Electrical Machines A 240 V DC series motor takes 40 A when giving its rated output at 1500 rpm. Its resistance is 0.3 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. 1.9 ohms. 6 ohms. 5.7 ohms. 2.2 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC machine, which of these parameters remain the same whether it runs as a DC motor or a DC generator? Armature current. Induced emf. Mechanical power. Can not be determined. Armature current. Induced emf. Mechanical power. Can not be determined. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The squirrel cage induction motors are provided with blades in order to facilitate cooling of rotor. none of these. balance the rotor dynamically. eliminate noise. facilitate cooling of rotor. none of these. balance the rotor dynamically. eliminate noise. 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, 3 2, 4 1, 4 2, 3 1, 3 2, 4 1, 4 2, 3 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a 3-phase induction motor, torque and supply voltage are related as T ∝ V T∝ V² T ∝ 1/V T ∝ 1/V² T ∝ V T∝ V² T ∝ 1/V T ∝ 1/V² ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a fault at the terminal of a synchronous generator, the fault current is maximum for a line to line fault. 3 - phase fault. line to ground fault. 3 - phase to ground fault. line to line fault. 3 - phase fault. line to ground fault. 3 - phase to ground fault. ANSWER DOWNLOAD EXAMIANS APP
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