Electrical Machines The commutator segments of DC machines are made up of brass copper alloy copper hard-drawn copper brass copper alloy copper hard-drawn copper 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 15.1 Ω 31.9 Ω 15.9 Ω 31.1 Ω 15.1 Ω 31.9 Ω 15.9 Ω 31.1 Ω ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines If Pi and Pc represent core and full load copper loss respectively, the maximum KVA delivered to load corresponding to maximum efficiency is equal to rated KVA is Pi/Pc (Pi/Pc)2 Pc/Pi √(Pi/Pc) Pi/Pc (Pi/Pc)2 Pc/Pi √(Pi/Pc) ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines For small value armature current Ia the torque developed by a DC series motor is proportional to Ia. √Ia. 1/Ia. Ia2. Ia. √Ia. 1/Ia. Ia2. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines The factors that are responsible for decrease in terminal voltage of a shunt generator are armature resistance, inter poles, armature. armature resistance, effect of armature reaction. armature resistance, effect of armature reaction. reduction in field current, effect of armature reaction, armature. armature resistance, inter poles, armature. armature resistance, effect of armature reaction. armature resistance, effect of armature reaction. reduction in field current, effect of armature reaction, armature. ANSWER DOWNLOAD EXAMIANS APP
Electrical Machines What is/are the necessary conditions for parallel operation of alternators? Both 1and 2 Speed of alternators should be same Terminal voltage is same Frequency should be same Both 1and 2 Speed of alternators should be same Terminal voltage is same Frequency should be same ANSWER DOWNLOAD EXAMIANS APP
EXAMIANS