Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where The accuracy in speed control is required. All of above. The speed in both the direction is required. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. All of above. The speed in both the direction is required. Very fine speed control over the whole range from zero to normal speed is required. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Sparkless commutation can be achieved by employing high resistance carbon brushes. any one or more of the above methods. compensating winding. inter poles. high resistance carbon brushes. any one or more of the above methods. compensating winding. inter poles. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The armature resistance of a permanent magnet dc motor is 0.8 Ohm. At no load, the motor draws 1.5 A from a supply voltage of 25 V and runs at 1500 rpm. The efficiency of the motor while it is operating on load at 1500 rpm drawing a current of 3.5 A from the same source will be 59.2%. 57.1%. 48.0%. 88.8%. 59.2%. 57.1%. 48.0%. 88.8%. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The primary and secondary windings of a transformer are electrically linked. inductively linked. mechanically linked. conductively linked. electrically linked. inductively linked. mechanically linked. conductively linked. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The mechanical power is developed by a DC motor is maximum when back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. none of above. back emf is equal to applied voltage. back emf is equal to twice of applied voltage. back emf is equal to half of applied voltage. none of above. back emf is equal to applied voltage. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 4 pole wave wound dc motor having flux per pole of 9.56 X 10-3 Wb contains 460 armature conductors with armature resistance of 0.6 ohm. Calculate the starting current flowing through the armature if the supply voltage is 240 volt. 0.5 Amp. 320 Amp. 800 Amp. 400 Amp. 0.5 Amp. 320 Amp. 800 Amp. 400 Amp. ANSWER DOWNLOAD EXAMIANS APP