Electrical Machines Oil is provided in an oil filled transformer for cooling. insulating. both cooling and insulation. lubrication. cooling. insulating. both cooling and insulation. lubrication. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt generator, when driven without any excitation, showed an open circuit voltage of 12 V. When the field winding was excited, the voltage dropped to zero. It happened because field resistance was higher than critical resistance there was no residual magnetism in the field circuit there was a break in the armature circuit field winding was wrongly connected field resistance was higher than critical resistance there was no residual magnetism in the field circuit there was a break in the armature circuit field winding was wrongly connected ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Which of the following is done in speed control of DC motor by field flux control? Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. Inserting resistance to armature circuit and field circuit. Any of above. Inserting an additional resistance in the field circuit. Inserting an additional resistance in the armature circuit. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A DC cumulatively compounded motor delivers rated load torque at rated speed. If the series field is short-circuited, then the armature current and speed will increase and decrease respectively both decrease decrease and increase respectively both increase increase and decrease respectively both decrease decrease and increase respectively both increase ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For a given torque, reducing diverter resistance of a DC series motor causes increase in speed demanding more armature current. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed but armature currnet remains the same. increase in speed demanding more armature current. decrease in speed but armature current remains the same. decrease in speed demanding less armature current. increase in speed but armature currnet remains the same. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Compensating windings are used in DC generators mainly to reduce the eddy currents by providing local short circuit. None of these to provide path for the circulation of cooling air. to neutralize the cross magnetizing effect of the armature reaction. mainly to reduce the eddy currents by providing local short circuit. None of these to provide path for the circulation of cooling air. to neutralize the cross magnetizing effect of the armature reaction. ANSWER DOWNLOAD EXAMIANS APP