Electrical Machines Ward-Leonard system for controlling the speed of a DC motor is used where Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. The speed in both the direction is required. All of above. Very fine speed control over the whole range from zero to normal speed is required. The accuracy in speed control is required. The speed in both the direction is required. All of above. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Sparkless commutation can be achieved by employing any one or more of the above methods. high resistance carbon brushes. inter poles. compensating winding. any one or more of the above methods. high resistance carbon brushes. inter poles. compensating winding. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following methods of speed control is not affected through stator side? Change of rotor resistance. Change of supply voltage. Change of number of pole. Change of supply frequency. Change of rotor resistance. Change of supply voltage. Change of number of pole. Change of supply frequency. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Induction motors normally use cast aluminium rotor because aluminium is easy to cast owing to its low melting point and is easily available. lighter in weight. cheaper in cost. of low resistivity. easy to cast owing to its low melting point and is easily available. lighter in weight. cheaper in cost. of low resistivity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The direction of rotation of a 3 - Φ induction motor is clockwise when it is supplied with 3 - Φ sinusoidal voltage having phase sequence A - B - C. For counterclockwise rotation of motor, the phase sequence of the supply should be A - C - B. B - C - A or C - A - B. C - A - B. B - C - A. A - C - B. B - C - A or C - A - B. C - A - B. B - C - A. 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 half of applied voltage. back emf is equal to twice of applied voltage. back emf is equal to applied voltage. none of above. back emf is equal to half of applied voltage. back emf is equal to twice of applied voltage. ANSWER DOWNLOAD EXAMIANS APP