Electrical Machines A DC motor with armature resistance of 0.5 ohms is connected directly to a 230 Volt supply. If the armature is stationary then the current flowing through armature is 570 A. 250 A. 460 A. 340 A. 570 A. 250 A. 460 A. 340 A. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In a seperately excited DC Motor if field current is increased, it will Increase acceleration duration. Reduce armature heating. Reduce starting torque. Increase speed Increase acceleration duration. Reduce armature heating. Reduce starting torque. Increase speed ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the handle of a three point starter goes to back to OFF position, it may be due to zero or very low voltage supply. all of these. over load. high filed circuit resistance. zero or very low voltage supply. all of these. over load. high filed circuit resistance. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the field circuit of a DC shunt motor is opened DC Shunt Motor The armature current will reduce. The motor will attain dangerously high speed. The speed of motor will be reduced. DC Shunt Motor The armature current will reduce. The motor will attain dangerously high speed. The speed of motor will be reduced. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Thin laminations are used in a machine in order to reduce Hysteresis losses Both 1 and 2 Copper losses Eddy current losses Hysteresis losses Both 1 and 2 Copper losses Eddy current losses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following factors improve commutation in a dc machine ? 1. High contact resistance of brushes 2. High inductance of the coils undergoing commutation 3. Shifting of brushes in the direction of rotation for a generator and in the opposite direction For a motor 4. Narrow width for the commutation bars Select the correct answer using the codes given below : Codes : 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 2, 3 and 4 1, 2 and 4 1, 2, and 3 1 and 3 ANSWER DOWNLOAD EXAMIANS APP
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