Electrical Machines Hopkinson test is conducted under which of the following condition? full load any of the above half load no load full load any of the above half load no load ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Consider the following statements : Interpoles in dc machines 1. reducearmature reaction effects in the interpolar region 2. have the same dimension as main polls 3. have their windings connected in series with the armature 4. have same number of turns as the armature 5. have the polarity same as that of the main pole ahead in a motor From these, the correct statements are 1, 3 and 5 1, 2 and 3 1 and 3 1, 2, 3 and 5 1, 3 and 5 1, 2 and 3 1 and 3 1, 2, 3 and 5 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For higher values of armature, the speed of a DC series motor is Constant. Proportional to the square of armature current. Inversely proportional to armature current. Proportional to armature current. Constant. Proportional to the square of armature current. Inversely proportional to armature current. Proportional to armature current. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 230 V, 50 Hz, 4 pole single phase induction motor is rotating in the clockwise ( forward ) direction at a speed of 1425 rpm. If the rotor resistance at standstill is 7.8 Ω. Then the effective rotor resistance in the backward branch of the equivalent circuit will be 4 Ω. 8 Ω. 2 Ω. 10 Ω. 4 Ω. 8 Ω. 2 Ω. 10 Ω. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Under operating conditions the rotor conductor should be _________________ in induction motor. always closed. semi closed or semi opened. always opened. none. always closed. semi closed or semi opened. always opened. none. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC shunt generator builds up to a voltage of 220 V at no load while running at its rated speed. If the speed of the generator is raised by 25% kepping the circuit conditions unaltered, then the Voltage to which the machine would build up will increase to 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V increase to a value greater than 1.25 times 220 V increase to 1.25 times 220 V increase to value lying between 220 V and 1.25 times 220 V not change and remain at 220 V increase to a value greater than 1.25 times 220 V ANSWER DOWNLOAD EXAMIANS APP