Electrical Machines Sparkless commutation can be achieved by employing inter poles. compensating winding. 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. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A dc shunt motor runs at a no-load speed of 1140 rpm. At full load, armature reaction weakens the main flux by 5% whereas the armature circuit voltage drops by 10%. The motor full-load speed in rpm is 1080 1200 1203 1000 1080 1200 1203 1000 ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines When the armature current of 5 Amp is flowing through the dc motor the torque produced is 47 Nm. Keeping the speed constant if the armature current is increased to 7 amp, calculate the new torque. Assume losses to be constant. 27.73 Nm . 65.8 Nm. 38.5 Nm. 74 Nm. 27.73 Nm . 65.8 Nm. 38.5 Nm. 74 Nm. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines In which of the following generators negative voltage regulation can occur? over compound generator both B and C shunt generator series generators over compound generator both B and C shunt generator series generators ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If the number of rotor slots is equal to number of stator slots, then motor refuses to start. Hence it is known as relative speed. air gap. cogging. crawling. relative speed. air gap. cogging. crawling. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines A 240 V, dc shunt motor draws 15 A while supplying the rated load at a speed of 80 rad/s. The armature resistance is 0.5 W and the field winding resistance is 80 W. The external resistance to be added in the armature circuit to limit the armature current to 125% of its rated value is 15.9 Ω 31.9 Ω 31.1 Ω 15.1 Ω 15.9 Ω 31.9 Ω 31.1 Ω 15.1 Ω ANSWER DOWNLOAD EXAMIANS APP