Electrical Machines A commutator with a diameter of 50 cm rotating at 1000 rpm. For a brush width of 1.5 cm, find the time of commutation in ms. 0.649. 0.443. 0.512. 0.573. 0.649. 0.443. 0.512. 0.573. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer, the frequency of a voltage at the secondary is less than primary. equal to primary. any of the above. greater than the primary. less than primary. equal to primary. any of the above. greater than the primary. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a transformer the magnetic coupling between the primary and secondary winding can be increased by using the magnetic core of low reluctance. using transformer oil of better quality. increasing the number of turns. using soft material for winding. using the magnetic core of low reluctance. using transformer oil of better quality. increasing the number of turns. using soft material for winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The current drawn by the armature of DC motor is directly proportional to None of above. The speed of motor. The torque required. The voltage across the terminals. None of above. The speed of motor. The torque required. The voltage across the terminals. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A short-shunt cumulatively-compounded dc generator builds up a voltage of 220 V at no load at rated speed. If it is operated as a differentially compounded generator, other things remaining the same, it would build up more than 220 V somewhat less than 220 V 6 V 220 V more than 220 V somewhat less than 220 V 6 V 220 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Two identical loss less series motors connected in series across a dc supply voltage, runs at speed of N1 and N2, then ratio of their output power is N1 : N2. N12 : N22. 1 : 1. none. N1 : N2. N12 : N22. 1 : 1. none. ANSWER DOWNLOAD EXAMIANS APP