Electrical Machines In a DC machine current and emf in armature are alternating. current and emf in armature are unidirectional current and emf at the terminals are alternating. emf in armature conductors and at the terminals is alternating. current and emf in armature are alternating. current and emf in armature are unidirectional current and emf at the terminals are alternating. emf in armature conductors and at the terminals is alternating. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines An electric motor with constant output power will have a torque speed characteristics in the form of a Straight line through the origin. Circle about the origin. Rectangular hyperbola Straight line parallel to the speed axis. Straight line through the origin. Circle about the origin. Rectangular hyperbola Straight line parallel to the speed axis. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because field resistance was higher than critical resistance there was no residual magnetism in the field circuit there was a break in the armature circuit field winding was wrongly connected field resistance was higher than critical resistance there was no residual magnetism in the field circuit there was a break in the armature circuit field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The change in speed of a DC generator due to increased load is corrected by increasing armature resistance. increasing terminal voltage. increasing input power of the prime mover. increasing armature cooling. increasing armature resistance. increasing terminal voltage. increasing input power of the prime mover. increasing armature cooling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of following methods are suitable for the speed control of squirrel cage induction motor? 1. Voltage control. 2. Frequency control. 3. Pole changing method. 4. Rotor resistance control select the correct answer using the codes given below:- 2 and 4. 1, 3 and 4. 2, 3 and 4. 1, 2 and 3. 2 and 4. 1, 3 and 4. 2, 3 and 4. 1, 2 and 3. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of a dc motor the ratio Eb / E is indicative of ratio of starting to running torque. ratio of starting to running current. efficiency. ratio of input to output voltage. ratio of starting to running torque. ratio of starting to running current. efficiency. ratio of input to output voltage. ANSWER DOWNLOAD EXAMIANS APP
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