Electrical Machines The direction of rotation of a 3 - Φ induction motor can be reversed by transposing all the three leads from the supply. transposing any two leads from supply. transposing any two leads from slip rings. disconnecting any one phase. transposing all the three leads from the supply. transposing any two leads from supply. transposing any two leads from slip rings. disconnecting any one phase. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 250 volt dc series motor having an armature resistance of 0.2 Ω takes a load current of 60 A. What will be the torque produced at the shaft of the motor? Consider brush drop of 1V. 266.20 N-m. 133.22 N-m can not be determined. 234.76 N-m. 266.20 N-m. 133.22 N-m can not be determined. 234.76 N-m. 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 ohms. The value of resistance which must be added to obtain rated torque at 1000 rpm is 1.9 ohms. 5.7 ohms. 6 ohms. 2.2 ohms. 1.9 ohms. 5.7 ohms. 6 ohms. 2.2 ohms. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 2 pole synchronous machine is operating at 3000 rpm. Find the relation between electrical angular momentum (ωe) and mechanical angular momentum (ωm) ? ωe = 2*ωm ωe = 4*ωm ωe = ωm ωe = 1/2*ωm ωe = 2*ωm ωe = 4*ωm ωe = ωm ωe = 1/2*ωm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The rotor speed of an induction motor is given by Nr = 120f / p × (1-s). None of these Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). Nr = 120f / p × (1-s). None of these Ns = 120f /p × ( 1 - r). Ns = 120f / p × ( 1 - s ). ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under which of the following conditions hunting of synchronous motor is likely to occur ? Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. Over-excitation. Periodic variation of load. Over-loading for long period. Small and constant load. ANSWER DOWNLOAD EXAMIANS APP
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