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. 220 V. 150 V. 280 V. 240 V. 220 V. 150 V. 280 V. 240 V. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When two DC series motors are connected in parallel, the resultant speed is more than normal speed. zero. normal speed. less than normal speed. more than normal speed. zero. normal speed. less than normal speed. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Maximum allowable tan - delta (tanδ) of dielectric dispassion factor of power transformer insulating oil is generally taken as 1 at 90°C. 2 at 90°C. 0.5 at 90°C. 3 at 90°C. 1 at 90°C. 2 at 90°C. 0.5 at 90°C. 3 at 90°C. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If terminal voltage of one 1000 rpm shunt motor is reduced to half the speed of the motor will be 1000 rpm 2000 rpm 250 rpm 500 rpm 1000 rpm 2000 rpm 250 rpm 500 rpm ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The speed of a motor falls from 1100 r.p.m at no-load to 1050 r.p.m at rated load. The speed regulation of motor is 2.57 %. 2.56 %. 4.76%. 3.76%. 2.57 %. 2.56 %. 4.76%. 3.76%. 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. 1, 2 and 3. 2, 3 and 4. 2 and 4. 1, 3 and 4. 1, 2 and 3. 2, 3 and 4. ANSWER DOWNLOAD EXAMIANS APP