Electrical Machines A transformer has maximum efficiency at 3/4 load. The ratio of iron loss and full load copper loss is 9/16. 16/9. 4/3. 3/4. 9/16. 16/9. 4/3. 3/4. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. back emf is equal to applied voltage. none of above. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For 250 volt DC Shunt Motor the armature and field resistance are 0.5 ohm and 250 ohm respectively. What will be the back e.m.f. produced when it takes a load current of 21A. 150 V. 240 V. 280 V. 220 V. 150 V. 240 V. 280 V. 220 V. 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 input power of the prime mover. increasing armature cooling. increasing terminal voltage. increasing armature resistance. increasing input power of the prime mover. increasing armature cooling. increasing terminal voltage. 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 220 V 6 V more than 220 V somewhat less than 220 V 220 V 6 V more than 220 V somewhat less than 220 V ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of 3 - Φ IM, plugging means pulling the motor directly on line without a rotor. interchanging two supply phases for quick stopping. starting the motor on load which is more than the rated load. locking of rotor due to harmonics. pulling the motor directly on line without a rotor. interchanging two supply phases for quick stopping. starting the motor on load which is more than the rated load. locking of rotor due to harmonics. ANSWER DOWNLOAD EXAMIANS APP
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