Electrical Machines A cumulatively compounded dc motor delivers rated load power at rated speed. If the series field is short-circuited, then both decrese both armature current Ia and speed ωm increase Ia remains constant but ωm increase Ia increases and ωm decreses both decrese both armature current Ia and speed ωm increase Ia remains constant but ωm increase Ia increases and ωm decreses ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor has external resistance Ra and Rf in the armature and field circuits respectively. Armature current at starting can be reduced by keeping Rf maximum and Ra minimum Ra maximum and Rf maximum Ra minimum and Rf minimum Ra maximum and Rf minimum Rf maximum and Ra minimum Ra maximum and Rf maximum Ra minimum and Rf minimum Ra maximum and Rf minimum 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 winding was wrongly connected there was no residual magnetism in the field circuit there was a break in the armature circuit field resistance was higher than critical resistance field winding was wrongly connected there was no residual magnetism in the field circuit there was a break in the armature circuit field resistance was higher than critical resistance ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines Dynamic braking is very effective for separately excited motors. series motors. differential compound motors. shunt motors. separately excited motors. series motors. differential compound motors. shunt motors. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When a transformer is loaded, the secondary terminal voltage drops. That means power factor is zero. leading. lagging. unity. zero. leading. lagging. unity. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For higher values of armature, the speed of a DC series motor is Constant. Inversely proportional to armature current. Proportional to the square of armature current. Proportional to armature current. Constant. Inversely proportional to armature current. Proportional to the square of armature current. Proportional to armature current. ANSWER DOWNLOAD EXAMIANS APP
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