Electrical Machines For a DC Shunt Motor having armature resistance of 0.5 Ω and 2A armature current at no-load, when the armature current is changed to 20A at loaded condition the speed is 1000 r.p.m. What is the speed at no-load? 1130 r.p.m. 963.8 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. 1130 r.p.m. 963.8 r.p.m. 4575.4 r.p.m. 1037.5 r.p.m. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC series motor is running with a divertor connected across its field winding. If the divertor resistance is reduced then the speed of the motor will increase. become execessively high. decrease. remain unaltered. increase. become execessively high. decrease. remain unaltered. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements regarding the speed control of dc motors : 1. ward-leonard method is suitable forconstant-torque drives 2. Ward-leonard method is suitable for constant-power drives 3. field-control method facilitates speed control below base speed 4. Armature-resistance control method is more efficient than ward-leanard method 5. Field-control method is suitable for constant-torque drives 6. Armature-resistance control method is suitable for constant-torque drives From these, the correct answer is 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 1, 2, 6 1, 4, 6 1, 3, 5 1, 2, 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Direct-on-line (DOL) starters are not suitable for starting large DC motors, because the starting torque becomes low. the starting current will be enormously high. the motor may not start. the motor may run away. the starting torque becomes low. the starting current will be enormously high. the motor may not start. the motor may run away. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a DC Shunt Motor the speed can be increased by Increasing the field current. Increasing the armature current. Decreasing the field current. Increasing the field current. Increasing the field current. Increasing the armature current. Decreasing the field current. Increasing the field current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Synchronous reactance of an alternator represents a reactance operating at synchronous speed field winding reactance armature reactance and leakage reactance All of these a reactance operating at synchronous speed field winding reactance armature reactance and leakage reactance All of these ANSWER DOWNLOAD EXAMIANS APP
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