Electrical Machines Direction of rotation of DC motor is reversed by Interchanging armature and field connection. Reversing supply connection. Adding resistance to field circuit. Reversing armature connection or field connection. Interchanging armature and field connection. Reversing supply connection. Adding resistance to field circuit. Reversing armature connection or field connection. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Autotransformer makes effective saving on copper and copper losses, when its transformation ratio is equal to greater than one. approx to one. very low less than one. greater than one. approx to one. very low less than one. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines At slip s = 1 torque developed in machine is starting torque. maximum torque. electromagnetic torque. none. starting torque. maximum torque. electromagnetic torque. none. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In case of induction motors the ratio of length to pole pitch for minimum cost, is taken as 1.0. 2 to 3. 1.5 to 2. 3 to 5. 1.0. 2 to 3. 1.5 to 2. 3 to 5. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 220 V, DC shunt motor is operating at a speed of 1440 rpm. The armature resistance is 1.0 Ω and armature current is 10 A. of the excitation of the machine is reduced by 10%, the extra resistance to be put in the armature circuit to maintain the same speed and torque will be 2 .1 Ω 1.79 Ω 1.8 9 Ω 3.1 Ω 2 .1 Ω 1.79 Ω 1.8 9 Ω 3.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is power factor of a 3 - φ induction motor at no load? Equal to 1. Same as full load. High. Low. Equal to 1. Same as full load. High. Low. ANSWER DOWNLOAD EXAMIANS APP
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